大军
大军

spring学习之源码分析--DefaultListableBeanFactory

DefaultListableBeanFactory

DefaultListableBeanFactory，继承了AbstractAutowireCapableBeanFactory及实现了ConfigurableListableBeanFactory、BeanDefinitionRegistry接口。

类结构

略

字段

// JSR-330 支持
private static Class javaxInjectProviderClass;
// DefaultListableBeanFactory引用的缓存
private static final Map> serializableFactories = new ConcurrentHashMap<>(8);
// 序列号id
private String serializationId;
// 是否允许用相同的名称重新注册不同的定义
private boolean allowBeanDefinitionOverriding = true;
// 是否允许懒加载
private boolean allowEagerClassLoading = true;
// 依赖排序顺序
private Comparator dependencyComparator;
// 解析器，用于检查bean定义是否为自动装配候选
private AutowireCandidateResolver autowireCandidateResolver = new SimpleAutowireCandidateResolver();
// 依赖类型和自动注入值的映射
private final Map, Object> resolvableDependencies = new ConcurrentHashMap<>(16);
// BeanDefinition和beanName的映射
private final Map beanDefinitionMap = new ConcurrentHashMap<>(256);
// 依赖类型和单例、非单例bean的映射
private final Map, String[]> allBeanNamesByType = new ConcurrentHashMap<>(64);
// 依赖类型和单例bean的映射
private final Map, String[]> singletonBeanNamesByType = new ConcurrentHashMap<>(64);
// bean定义名称列表，按注册顺序排列。
private volatile List beanDefinitionNames = new ArrayList<>(256);
// 手动注册的单例，按注册顺序排列
private volatile Set manualSingletonNames = new LinkedHashSet<>(16);
// 固定配置的缓存的bean定义名数组
private volatile String[] frozenBeanDefinitionNames;
// 是否可以缓存所有bean的bean定义元数据
private volatile boolean configurationFrozen = false; 
 
方法解析
 
 
DefaultListableBeanFactory
 
 
构造方法
 
 
public DefaultListableBeanFactory() {
    super();
}
public DefaultListableBeanFactory(@Nullable BeanFactory parentBeanFactory) {
    super(parentBeanFactory);
}
 
 
setSerializationId
 
 
getSerializationId
 
 
序列号设置，同时设置到serializableFactories中。
 
 
public void setSerializationId(@Nullable String serializationId) {
    if (serializationId != null) {
        serializableFactories.put(serializationId, new WeakReference<>(this));
    }
    else if (this.serializationId != null) {
        serializableFactories.remove(this.serializationId);
    }
    this.serializationId = serializationId;
}
public String getSerializationId() {
    return this.serializationId;
}
 
 
setAllowBeanDefinitionOverriding
 
 
isAllowBeanDefinitionOverriding
 
 
setAllowEagerClassLoading
 
 
isAllowEagerClassLoading
 
 
setDependencyComparator
 
 
getDependencyComparator
 
 
setAutowireCandidateResolver
 
 
getAutowireCandidateResolver
 
 
allowAliasOverriding
 
 
set、get代码略
 
 
copyConfigurationFrom
 
 
复制其他配置信息
 
 
public void copyConfigurationFrom(ConfigurableBeanFactory otherFactory) {
    super.copyConfigurationFrom(otherFactory);
    if (otherFactory instanceof DefaultListableBeanFactory) {
        DefaultListableBeanFactory otherListableFactory = (DefaultListableBeanFactory) otherFactory;
        this.allowBeanDefinitionOverriding = otherListableFactory.allowBeanDefinitionOverriding;
        this.allowEagerClassLoading = otherListableFactory.allowEagerClassLoading;
        this.dependencyComparator = otherListableFactory.dependencyComparator;
        // A clone of the AutowireCandidateResolver since it is potentially BeanFactoryAware...
        setAutowireCandidateResolver(BeanUtils.instantiateClass(getAutowireCandidateResolver().getClass()));
        // Make resolvable dependencies (e.g. ResourceLoader) available here as well...
        this.resolvableDependencies.putAll(otherListableFactory.resolvableDependencies);
    }
}
 
 
getBean
 
 
获取bean
 
 
public  T getBean(Class requiredType) throws BeansException {
    // 根据class类型获取bean
    return getBean(requiredType, (Object[]) null);
}
public  T getBean(Class requiredType, @Nullable Object... args) throws BeansException {
    Object resolved = resolveBean(ResolvableType.forRawClass(requiredType), args, false);
    if (resolved == null) {
        throw new NoSuchBeanDefinitionException(requiredType);
    }
    return (T) resolved;
}
 
 
getBeanProvider
 
 
获取bean的提供者
 
 
public  ObjectProvider getBeanProvider(Class requiredType) throws BeansException {
    return getBeanProvider(ResolvableType.forRawClass(requiredType));
}
public  ObjectProvider getBeanProvider(ResolvableType requiredType) {
    return new BeanObjectProvider() {
        @Override
        public T getObject() throws BeansException {
            T resolved = resolveBean(requiredType, null, false);
            if (resolved == null) {
                throw new NoSuchBeanDefinitionException(requiredType);
            }
            return resolved;
        }
        @Override
        public T getObject(Object... args) throws BeansException {
            T resolved = resolveBean(requiredType, args, false);
            if (resolved == null) {
                throw new NoSuchBeanDefinitionException(requiredType);
            }
            return resolved;
        }
        @Override
        @Nullable
        public T getIfAvailable() throws BeansException {
            return resolveBean(requiredType, null, false);
        }
        @Override
        @Nullable
        public T getIfUnique() throws BeansException {
            return resolveBean(requiredType, null, true);
        }
        @Override
        public Stream stream() {
            return Arrays.stream(getBeanNamesForTypedStream(requiredType))
                    .map(name -> (T) getBean(name))
                    .filter(bean -> !(bean instanceof NullBean));
        }
        @Override
        public Stream orderedStream() {
            String[] beanNames = getBeanNamesForTypedStream(requiredType);
            Map matchingBeans = new LinkedHashMap<>(beanNames.length);
            for (String beanName : beanNames) {
                Object beanInstance = getBean(beanName);
                if (!(beanInstance instanceof NullBean)) {
                    matchingBeans.put(beanName, (T) beanInstance);
                }
            }
            Stream stream = matchingBeans.values().stream();
            return stream.sorted(adaptOrderComparator(matchingBeans));
        }
    };
}
 
 
resolveBean
 
 
private  T resolveBean(ResolvableType requiredType, @Nullable Object[] args, boolean nonUniqueAsNull) {
    NamedBeanHolder namedBean = resolveNamedBean(requiredType, args, nonUniqueAsNull);
    if (namedBean != null) {
        return namedBean.getBeanInstance();
    }
    BeanFactory parent = getParentBeanFactory();
    // 如果父类是DefaultListableBeanFactory，调用父类的resolveBean方法
    if (parent instanceof DefaultListableBeanFactory) {
        return ((DefaultListableBeanFactory) parent).resolveBean(requiredType, args, nonUniqueAsNull);
    }
    else if (parent != null) {
        // 如果父类不是DefaultListableBeanFactory，且不为空，获取父类的bean的提供者
        ObjectProvider parentProvider = parent.getBeanProvider(requiredType);
        if (args != null) {
            // 有参构造
            return parentProvider.getObject(args);
        }
        else {
            // 无参构造，getIfAvailable：实际存在才返回一个实例，*   getIfUnique： 有多个实例时，返回默认的实例（比如primary）
            return (nonUniqueAsNull ? parentProvider.getIfUnique() : parentProvider.getIfAvailable());
        }
    }
    return null;
}
 
 
getBeanNamesForTypedStream
 
 
通过ResolvableType获取bean名称
 
 
private String[] getBeanNamesForTypedStream(ResolvableType requiredType) {
    return BeanFactoryUtils.beanNamesForTypeIncludingAncestors(this, requiredType);
}
 
 
containsBeanDefinition
 
 
检查此bean工厂是否包含具有指定名称的bean定义。不考虑本工厂可能参与的任何层级
 
 
public boolean containsBeanDefinition(String beanName) {
    Assert.notNull(beanName, "Bean name must not be null");
    return this.beanDefinitionMap.containsKey(beanName);
}
 
 
getBeanDefinitionCount
 
 
获取bean定义的个数
 
 
public int getBeanDefinitionCount() {
    return this.beanDefinitionMap.size();
}
 
 
getBeanDefinitionNames
 
 
不考虑此工厂可能参与的任何层次结构，并且忽略通过bean定义以外的其他方式注册的任何单例bean
 
 
public String[] getBeanDefinitionNames() {
    String[] frozenNames = this.frozenBeanDefinitionNames;
    if (frozenNames != null) {
        return frozenNames.clone();
    }
    else {
        return StringUtils.toStringArray(this.beanDefinitionNames);
    }
}
 
 
getBeanNamesForType
 
 
根据bean定义或factorybean中getObjectType的值判断，返回与给定类型(包括子类)匹配的bean的名称。
 
 
public String[] getBeanNamesForType(ResolvableType type) {
    Class resolved = type.resolve();
    if (resolved != null && !type.hasGenerics()) {
        return getBeanNamesForType(resolved, true, true);
    }
    else {
        return doGetBeanNamesForType(type, true, true);
    }
}

public String[] getBeanNamesForType(@Nullable Class type) {
    return getBeanNamesForType(type, true, true);
}

@Override
public String[] getBeanNamesForType(@Nullable Class type, boolean includeNonSingletons, boolean allowEagerInit) {
    if (!isConfigurationFrozen() || type == null || !allowEagerInit) {
        return doGetBeanNamesForType(ResolvableType.forRawClass(type), includeNonSingletons, allowEagerInit);
    }
    Map, String[]> cache =
            (includeNonSingletons ? this.allBeanNamesByType : this.singletonBeanNamesByType);
    String[] resolvedBeanNames = cache.get(type);
    if (resolvedBeanNames != null) {
        return resolvedBeanNames;
    }
    resolvedBeanNames = doGetBeanNamesForType(ResolvableType.forRawClass(type), includeNonSingletons, true);
    if (ClassUtils.isCacheSafe(type, getBeanClassLoader())) {
        cache.put(type, resolvedBeanNames);
    }
    return resolvedBeanNames;
}
 
 
doGetBeanNamesForType
 
 
根据bean定义或factorybean中getObjectType的值判断，返回与给定类型(包括子类)匹配的bean的名称。
 
 
private String[] doGetBeanNamesForType(ResolvableType type, boolean includeNonSingletons, boolean allowEagerInit) {
    List result = new ArrayList<>();

    // Check all bean definitions.
    // 遍历所有的beanName
    for (String beanName : this.beanDefinitionNames) {
        // Only consider bean as eligible if the bean name
        // is not defined as alias for some other bean.
        // 没有别名
        if (!isAlias(beanName)) {
            try {
                // 合并bean的定义
                RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
                // Only check bean definition if it is complete.
                if (!mbd.isAbstract() && (allowEagerInit ||
                        (mbd.hasBeanClass() || !mbd.isLazyInit() || isAllowEagerClassLoading()) &&
                                !requiresEagerInitForType(mbd.getFactoryBeanName()))) {
                    // In case of FactoryBean, match object created by FactoryBean.
                    // 是否是FactoryBean
                    boolean isFactoryBean = isFactoryBean(beanName, mbd);
                    BeanDefinitionHolder dbd = mbd.getDecoratedDefinition();
                    boolean matchFound =
                            (allowEagerInit || !isFactoryBean ||
                                    (dbd != null && !mbd.isLazyInit()) || containsSingleton(beanName)) &&
                            (includeNonSingletons ||
                                    (dbd != null ? mbd.isSingleton() : isSingleton(beanName))) &&
                            isTypeMatch(beanName, type);
                    if (!matchFound && isFactoryBean) {
                        // In case of FactoryBean, try to match FactoryBean instance itself next.
                        beanName = FACTORY_BEAN_PREFIX + beanName;
                        matchFound = (includeNonSingletons || mbd.isSingleton()) && isTypeMatch(beanName, type);
                    }
                    if (matchFound) {
                        result.add(beanName);
                    }
                }
            }
            catch (CannotLoadBeanClassException ex) {
                if (allowEagerInit) {
                    throw ex;
                }
                // Probably a class name with a placeholder: let's ignore it for type matching purposes.
                if (logger.isTraceEnabled()) {
                    logger.trace("Ignoring bean class loading failure for bean '" + beanName + "'", ex);
                }
                onSuppressedException(ex);
            }
            catch (BeanDefinitionStoreException ex) {
                if (allowEagerInit) {
                    throw ex;
                }
                // Probably some metadata with a placeholder: let's ignore it for type matching purposes.
                if (logger.isTraceEnabled()) {
                    logger.trace("Ignoring unresolvable metadata in bean definition '" + beanName + "'", ex);
                }
                onSuppressedException(ex);
            }
        }
    }

    // Check manually registered singletons too.
    for (String beanName : this.manualSingletonNames) {
        try {
            // In case of FactoryBean, match object created by FactoryBean.
            if (isFactoryBean(beanName)) {
                if ((includeNonSingletons || isSingleton(beanName)) && isTypeMatch(beanName, type)) {
                    result.add(beanName);
                    // Match found for this bean: do not match FactoryBean itself anymore.
                    continue;
                }
                // In case of FactoryBean, try to match FactoryBean itself next.
                beanName = FACTORY_BEAN_PREFIX + beanName;
            }
            // Match raw bean instance (might be raw FactoryBean).
            if (isTypeMatch(beanName, type)) {
                result.add(beanName);
            }
        }
        catch (NoSuchBeanDefinitionException ex) {
            // Shouldn't happen - probably a result of circular reference resolution...
            if (logger.isTraceEnabled()) {
                logger.trace("Failed to check manually registered singleton with name '" + beanName + "'", ex);
            }
        }
    }

    return StringUtils.toStringArray(result);
}
 
 
requiresEagerInitForType
 
 
是否马上返回bean以确定类型
 
 
private boolean requiresEagerInitForType(@Nullable String factoryBeanName) {
    return (factoryBeanName != null && isFactoryBean(factoryBeanName) && !containsSingleton(factoryBeanName));
}
 
 
getBeansOfType
 
 
获取bean名称和实例的映射
 
 
public  Map getBeansOfType(@Nullable Class type) throws BeansException {
    return getBeansOfType(type, true, true);
}

public  Map getBeansOfType(@Nullable Class type, boolean includeNonSingletons, boolean allowEagerInit)
        throws BeansException {
    // 根据类型获取到bean名称
    String[] beanNames = getBeanNamesForType(type, includeNonSingletons, allowEagerInit);
    Map result = new LinkedHashMap<>(beanNames.length);
    // 遍历所有名称，通过bean名称获取实例，如果不是NullBean加入到result
    for (String beanName : beanNames) {
        try {
            Object beanInstance = getBean(beanName);
            if (!(beanInstance instanceof NullBean)) {
                result.put(beanName, (T) beanInstance);
            }
        }
        catch (BeanCreationException ex) {
            Throwable rootCause = ex.getMostSpecificCause();
            if (rootCause instanceof BeanCurrentlyInCreationException) {
                BeanCreationException bce = (BeanCreationException) rootCause;
                String exBeanName = bce.getBeanName();
                if (exBeanName != null && isCurrentlyInCreation(exBeanName)) {
                    if (logger.isTraceEnabled()) {
                        logger.trace("Ignoring match to currently created bean '" + exBeanName + "': " +
                                ex.getMessage());
                    }
                    onSuppressedException(ex);
                    // Ignore: indicates a circular reference when autowiring constructors.
                    // We want to find matches other than the currently created bean itself.
                    continue;
                }
            }
            throw ex;
        }
    }
    return result;
}
 
 
getBeanNamesForAnnotation
 
 
根据注解获取bean的名称
 
 
public String[] getBeanNamesForAnnotation(Class annotationType) {
    List result = new ArrayList<>();
    // 遍历所有的bean的，把不是抽象类的，以及有annotationType注解的加入到result
    for (String beanName : this.beanDefinitionNames) {
        BeanDefinition beanDefinition = getBeanDefinition(beanName);
        if (!beanDefinition.isAbstract() && findAnnotationOnBean(beanName, annotationType) != null) {
            result.add(beanName);
        }
    }
    // 遍历所有的manualSingletonNames，把没有加入到result的以及有annotationType注解的加入到result
    for (String beanName : this.manualSingletonNames) {
        if (!result.contains(beanName) && findAnnotationOnBean(beanName, annotationType) != null) {
            result.add(beanName);
        }
    }
    return StringUtils.toStringArray(result);
}
 
 
getBeansWithAnnotation
 
 
根据注解获取bean的实例
 
 
public Map getBeansWithAnnotation(Class annotationType) {
    // 根据注解获取bean的名称
    String[] beanNames = getBeanNamesForAnnotation(annotationType);
    Map result = new LinkedHashMap<>(beanNames.length);
    // 遍历bean的名称，获取bean的实例
    for (String beanName : beanNames) {
        Object beanInstance = getBean(beanName);
        if (!(beanInstance instanceof NullBean)) {
            result.put(beanName, beanInstance);
        }
    }
    return result;
}
 
 
findAnnotationOnBean
 
 
根据beanName获取注解
 
 
public  A findAnnotationOnBean(String beanName, Class annotationType)
        throws NoSuchBeanDefinitionException {

    A ann = null;
    // 获取class
    Class beanType = getType(beanName);
    if (beanType != null) {
        // class不为空，获取注解
        ann = AnnotationUtils.findAnnotation(beanType, annotationType);
    }
    // 没获取到注解，且有定义过，从定义里的beanClass获取
    if (ann == null && containsBeanDefinition(beanName)) {
        BeanDefinition bd = getMergedBeanDefinition(beanName);
        if (bd instanceof AbstractBeanDefinition) {
            AbstractBeanDefinition abd = (AbstractBeanDefinition) bd;
            if (abd.hasBeanClass()) {
                ann = AnnotationUtils.findAnnotation(abd.getBeanClass(), annotationType);
            }
        }
    }
    return ann;
}
 
 
registerResolvableDependency
 
 
注册依赖类型和自动注入值
 
 
public void registerResolvableDependency(Class dependencyType, @Nullable Object autowiredValue) {
    Assert.notNull(dependencyType, "Dependency type must not be null");
    if (autowiredValue != null) {
        if (!(autowiredValue instanceof ObjectFactory || dependencyType.isInstance(autowiredValue))) {
            throw new IllegalArgumentException("Value [" + autowiredValue +
                    "] does not implement specified dependency type [" + dependencyType.getName() + "]");
        }
        this.resolvableDependencies.put(dependencyType, autowiredValue);
    }
}
 
 
isAutowireCandidate
 
 
指定的bean是否是自动注入的候选
 
 
public boolean isAutowireCandidate(String beanName, DependencyDescriptor descriptor)
        throws NoSuchBeanDefinitionException {

    return isAutowireCandidate(beanName, descriptor, getAutowireCandidateResolver());
}

protected boolean isAutowireCandidate(String beanName, DependencyDescriptor descriptor, AutowireCandidateResolver resolver)
        throws NoSuchBeanDefinitionException {

    String beanDefinitionName = BeanFactoryUtils.transformedBeanName(beanName);
    // 定义过的，从定义里找
    if (containsBeanDefinition(beanDefinitionName)) {
        return isAutowireCandidate(beanName, getMergedLocalBeanDefinition(beanDefinitionName), descriptor, resolver);
    }
    // 创建过的单例，重新创建RootBeanDefinition
    else if (containsSingleton(beanName)) {
        return isAutowireCandidate(beanName, new RootBeanDefinition(getType(beanName)), descriptor, resolver);
    }
    // 都没找到，从父类找
    BeanFactory parent = getParentBeanFactory();
    if (parent instanceof DefaultListableBeanFactory) {
        // No bean definition found in this factory -> delegate to parent.
        return ((DefaultListableBeanFactory) parent).isAutowireCandidate(beanName, descriptor, resolver);
    }
    else if (parent instanceof ConfigurableListableBeanFactory) {
        // If no DefaultListableBeanFactory, can't pass the resolver along.
        return ((ConfigurableListableBeanFactory) parent).isAutowireCandidate(beanName, descriptor);
    }
    else {
        return true;
    }
}

protected boolean isAutowireCandidate(String beanName, RootBeanDefinition mbd,
        DependencyDescriptor descriptor, AutowireCandidateResolver resolver) {

    String beanDefinitionName = BeanFactoryUtils.transformedBeanName(beanName);
    // 解析
    resolveBeanClass(mbd, beanDefinitionName);
    if (mbd.isFactoryMethodUnique && mbd.factoryMethodToIntrospect == null) {
        new ConstructorResolver(this).resolveFactoryMethodIfPossible(mbd);
    }
    // 从别名里找
    return resolver.isAutowireCandidate(
            new BeanDefinitionHolder(mbd, beanName, getAliases(beanDefinitionName)), descriptor);
}
 
 
getBeanDefinition
 
 
从beanDefinitionMap找bean的定义
 
 
public BeanDefinition getBeanDefinition(String beanName) throws NoSuchBeanDefinitionException {
    BeanDefinition bd = this.beanDefinitionMap.get(beanName);
    if (bd == null) {
        if (logger.isTraceEnabled()) {
            logger.trace("No bean named '" + beanName + "' found in " + this);
        }
        throw new NoSuchBeanDefinitionException(beanName);
    }
    return bd;
}
 
 
getBeanNamesIterator
 
 
获取bean的迭代名称，包括自定的和手动注册的
 
 
public Iterator getBeanNamesIterator() {
    CompositeIterator iterator = new CompositeIterator<>();
    iterator.add(this.beanDefinitionNames.iterator());
    iterator.add(this.manualSingletonNames.iterator());
    return iterator;
}
 
 
clearMetadataCache
 
 
public void clearMetadataCache() {
    super.clearMetadataCache();
    clearByTypeCache();
}
 
 
freezeConfiguration
 
 
冻结当前的bean的信息
 
 
public void freezeConfiguration() {
    this.configurationFrozen = true;
    this.frozenBeanDefinitionNames = StringUtils.toStringArray(this.beanDefinitionNames);
}
 
 
isConfigurationFrozen
 
 
public boolean isConfigurationFrozen() {
    return this.configurationFrozen;
}
 
 
isBeanEligibleForMetadataCaching
 
 
是否已经冻结了或者是否已创建
 
 
protected boolean isBeanEligibleForMetadataCaching(String beanName) {
    return (this.configurationFrozen || super.isBeanEligibleForMetadataCaching(beanName));
}
 
 
preInstantiateSingletons
 
 
确保实例化了所有非lazy-init单例
 
 
public void preInstantiateSingletons() throws BeansException {
    if (logger.isTraceEnabled()) {
        logger.trace("Pre-instantiating singletons in " + this);
    }

    // Iterate over a copy to allow for init methods which in turn register new bean definitions.
    // While this may not be part of the regular factory bootstrap, it does otherwise work fine.
    List beanNames = new ArrayList<>(this.beanDefinitionNames);

    // Trigger initialization of all non-lazy singleton beans...
    // 遍历beanNames
    for (String beanName : beanNames) {
        RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);
        // 不是抽象的，并且是单例且没有懒加载
        if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
            //FactoryBean的情况
            if (isFactoryBean(beanName)) {
                Object bean = getBean(FACTORY_BEAN_PREFIX + beanName);
                if (bean instanceof FactoryBean) {
                    final FactoryBean factory = (FactoryBean) bean;
                    boolean isEagerInit;
                    if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
                        isEagerInit = AccessController.doPrivileged((PrivilegedAction)
                                        ((SmartFactoryBean) factory)::isEagerInit,
                                getAccessControlContext());
                    }
                    else {
                        isEagerInit = (factory instanceof SmartFactoryBean &&
                                ((SmartFactoryBean) factory).isEagerInit());
                    }
                    if (isEagerInit) {
                        getBean(beanName);
                    }
                }
            }
            else {
                // 直接获取
                getBean(beanName);
            }
        }
    }

    // Trigger post-initialization callback for all applicable beans...
    // 获取单例bean后，如果是SmartInitializingSingleton类型，再调用afterSingletonsInstantiated方法
    for (String beanName : beanNames) {
        Object singletonInstance = getSingleton(beanName);
        if (singletonInstance instanceof SmartInitializingSingleton) {
            final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance;
            if (System.getSecurityManager() != null) {
                AccessController.doPrivileged((PrivilegedAction) () -> {
                    smartSingleton.afterSingletonsInstantiated();
                    return null;
                }, getAccessControlContext());
            }
            else {
                smartSingleton.afterSingletonsInstantiated();
            }
        }
    }
} 
 
registerBeanDefinition
 
 
public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition)
        throws BeanDefinitionStoreException {

    Assert.hasText(beanName, "Bean name must not be empty");
    Assert.notNull(beanDefinition, "BeanDefinition must not be null");
    
    if (beanDefinition instanceof AbstractBeanDefinition) {
        try {
            ((AbstractBeanDefinition) beanDefinition).validate();
        }
        catch (BeanDefinitionValidationException ex) {
            throw new BeanDefinitionStoreException(beanDefinition.getResourceDescription(), beanName,
                    "Validation of bean definition failed", ex);
        }
    }
    // 获取bean的定义
    BeanDefinition existingDefinition = this.beanDefinitionMap.get(beanName);
    if (existingDefinition != null) {
        // 存在的情况
        if (!isAllowBeanDefinitionOverriding()) {
            throw new BeanDefinitionOverrideException(beanName, beanDefinition, existingDefinition);
        }
        else if (existingDefinition.getRole() < beanDefinition.getRole()) {
            // e.g. was ROLE_APPLICATION, now overriding with ROLE_SUPPORT or ROLE_INFRASTRUCTURE
            if (logger.isInfoEnabled()) {
                logger.info("Overriding user-defined bean definition for bean '" + beanName +
                        "' with a framework-generated bean definition: replacing [" +
                        existingDefinition + "] with [" + beanDefinition + "]");
            }
        }
        else if (!beanDefinition.equals(existingDefinition)) {
            if (logger.isDebugEnabled()) {
                logger.debug("Overriding bean definition for bean '" + beanName +
                        "' with a different definition: replacing [" + existingDefinition +
                        "] with [" + beanDefinition + "]");
            }
        }
        else {
            if (logger.isTraceEnabled()) {
                logger.trace("Overriding bean definition for bean '" + beanName +
                        "' with an equivalent definition: replacing [" + existingDefinition +
                        "] with [" + beanDefinition + "]");
            }
        }
        this.beanDefinitionMap.put(beanName, beanDefinition);
    }
    else {
        // 不存在的情况，有bean创建了
        if (hasBeanCreationStarted()) {
            // Cannot modify startup-time collection elements anymore (for stable iteration)
            // 加锁
            synchronized (this.beanDefinitionMap) {
                // 设置以下三个信息
                this.beanDefinitionMap.put(beanName, beanDefinition);
                List updatedDefinitions = new ArrayList<>(this.beanDefinitionNames.size() + 1);
                updatedDefinitions.addAll(this.beanDefinitionNames);
                updatedDefinitions.add(beanName);
                this.beanDefinitionNames = updatedDefinitions;
                if (this.manualSingletonNames.contains(beanName)) {
                    Set updatedSingletons = new LinkedHashSet<>(this.manualSingletonNames);
                    updatedSingletons.remove(beanName);
                    this.manualSingletonNames = updatedSingletons;
                }
            }
        }
        else {
            // bean还没创建，赶紧设置以下三个信息
            // Still in startup registration phase
            this.beanDefinitionMap.put(beanName, beanDefinition);
            this.beanDefinitionNames.add(beanName);
            this.manualSingletonNames.remove(beanName);
        }
        this.frozenBeanDefinitionNames = null;
    }

    if (existingDefinition != null || containsSingleton(beanName)) {
        resetBeanDefinition(beanName);
    }
}
 
 
removeBeanDefinition
 
 
public void removeBeanDefinition(String beanName) throws NoSuchBeanDefinitionException {
    Assert.hasText(beanName, "'beanName' must not be empty");
    // 移除
    BeanDefinition bd = this.beanDefinitionMap.remove(beanName);
    // 为空说明之前不存在
    if (bd == null) {
        if (logger.isTraceEnabled()) {
            logger.trace("No bean named '" + beanName + "' found in " + this);
        }
        throw new NoSuchBeanDefinitionException(beanName);
    }
    // 已经创建bean了，要加锁
    if (hasBeanCreationStarted()) {
        // Cannot modify startup-time collection elements anymore (for stable iteration)
        synchronized (this.beanDefinitionMap) {
            List updatedDefinitions = new ArrayList<>(this.beanDefinitionNames);
            updatedDefinitions.remove(beanName);
            this.beanDefinitionNames = updatedDefinitions;
        }
    }
    else {
        // Still in startup registration phase
        // 还没创建，直接移除
        this.beanDefinitionNames.remove(beanName);
    }
    this.frozenBeanDefinitionNames = null;

    resetBeanDefinition(beanName);
}
 
 
resetBeanDefinition
 
 
重置bean的定义
 
 
protected void resetBeanDefinition(String beanName) {
    // Remove the merged bean definition for the given bean, if already created.
    // bean定义删除
    clearMergedBeanDefinition(beanName);

    // Remove corresponding bean from singleton cache, if any. Shouldn't usually
    // be necessary, rather just meant for overriding a context's default beans
    // (e.g. the default StaticMessageSource in a StaticApplicationContext).
    // bean销毁
    destroySingleton(beanName);

    // Notify all post-processors that the specified bean definition has been reset.
    for (BeanPostProcessor processor : getBeanPostProcessors()) {
        if (processor instanceof MergedBeanDefinitionPostProcessor) {
            ((MergedBeanDefinitionPostProcessor) processor).resetBeanDefinition(beanName);
        }
    }

    // Reset all bean definitions that have the given bean as parent (recursively).
    // 子类重置
    for (String bdName : this.beanDefinitionNames) {
        if (!beanName.equals(bdName)) {
            BeanDefinition bd = this.beanDefinitionMap.get(bdName);
            if (beanName.equals(bd.getParentName())) {
                resetBeanDefinition(bdName);
            }
        }
    }
}
 
 
registerSingleton
 
 
注册单例，手动注册的单例，保存在manualSingletonNames
 
 
public void registerSingleton(String beanName, Object singletonObject) throws IllegalStateException {
    super.registerSingleton(beanName, singletonObject);

    if (hasBeanCreationStarted()) {
        // Cannot modify startup-time collection elements anymore (for stable iteration)
        synchronized (this.beanDefinitionMap) {
            if (!this.beanDefinitionMap.containsKey(beanName)) {
                Set updatedSingletons = new LinkedHashSet<>(this.manualSingletonNames.size() + 1);
                updatedSingletons.addAll(this.manualSingletonNames);
                updatedSingletons.add(beanName);
                this.manualSingletonNames = updatedSingletons;
            }
        }
    }
    else {
        // Still in startup registration phase
        if (!this.beanDefinitionMap.containsKey(beanName)) {
            this.manualSingletonNames.add(beanName);
        }
    }

    clearByTypeCache();
}
 
 
destroySingleton
 
 
销毁bean，还要移除manualSingletonNames的bean
 
 
public void destroySingleton(String beanName) {
    super.destroySingleton(beanName);
    this.manualSingletonNames.remove(beanName);
    clearByTypeCache();
}
 
 
destroySingletons
 
 
销毁所有bean，还要移除manualSingletonNames的所有bean
 
 
public void destroySingletons() {
    super.destroySingletons();
    this.manualSingletonNames.clear();
    clearByTypeCache();
}
 
 
clearByTypeCache
 
 
清除依赖类型的映射
 
 
private void clearByTypeCache() {
    this.allBeanNamesByType.clear();
    this.singletonBeanNamesByType.clear();
}
 
 
resolveNamedBean
 
 
通过类型解析bean
 
 
public  NamedBeanHolder resolveNamedBean(Class requiredType) throws BeansException {
    NamedBeanHolder namedBean = resolveNamedBean(ResolvableType.forRawClass(requiredType), null, false);
    if (namedBean != null) {
        return namedBean;
    }
    // 为空去父类查找
    BeanFactory parent = getParentBeanFactory();
    if (parent instanceof AutowireCapableBeanFactory) {
        return ((AutowireCapableBeanFactory) parent).resolveNamedBean(requiredType);
    }
    throw new NoSuchBeanDefinitionException(requiredType);
}

private  NamedBeanHolder resolveNamedBean(
        ResolvableType requiredType, @Nullable Object[] args, boolean nonUniqueAsNull) throws BeansException {

    Assert.notNull(requiredType, "Required type must not be null");
    // 获取候选bean
    String[] candidateNames = getBeanNamesForType(requiredType);

    if (candidateNames.length > 1) {
        List autowireCandidates = new ArrayList<>(candidateNames.length);
        for (String beanName : candidateNames) {
            if (!containsBeanDefinition(beanName) || getBeanDefinition(beanName).isAutowireCandidate()) {
                autowireCandidates.add(beanName);
            }
        }
        if (!autowireCandidates.isEmpty()) {
            candidateNames = StringUtils.toStringArray(autowireCandidates);
        }
    }
    // 只有一个候选，就确定是这个了
    if (candidateNames.length == 1) {
        String beanName = candidateNames[0];
        return new NamedBeanHolder<>(beanName, (T) getBean(beanName, requiredType.toClass(), args));
    }
    else if (candidateNames.length > 1) {
        Map candidates = new LinkedHashMap<>(candidateNames.length);
        for (String beanName : candidateNames) {
            // 无参，直接获取bean的类型
            if (containsSingleton(beanName) && args == null) {
                Object beanInstance = getBean(beanName);
                candidates.put(beanName, (beanInstance instanceof NullBean ? null : beanInstance));
            }
            else {
                // 有参，通过beanName获取类型
                candidates.put(beanName, getType(beanName));
            }
        }
        // 获取主要的一个
        String candidateName = determinePrimaryCandidate(candidates, requiredType.toClass());
        if (candidateName == null) {
            // 没获取到，从最高级的获取
            candidateName = determineHighestPriorityCandidate(candidates, requiredType.toClass());
        }
        if (candidateName != null) {
            // 获取到了，创建一个NamedBeanHolder返回
            Object beanInstance = candidates.get(candidateName);
            if (beanInstance == null || beanInstance instanceof Class) {
                beanInstance = getBean(candidateName, requiredType.toClass(), args);
            }
            return new NamedBeanHolder<>(candidateName, (T) beanInstance);
        }
        if (!nonUniqueAsNull) {
            throw new NoUniqueBeanDefinitionException(requiredType, candidates.keySet());
        }
    }

    return null;
}
 
 
resolveDependency
 
 
根据工厂中定义的bean解析指定的依赖项
 
 
public Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName,
        @Nullable Set autowiredBeanNames, @Nullable TypeConverter typeConverter) throws BeansException {

    descriptor.initParameterNameDiscovery(getParameterNameDiscoverer());
    if (Optional.class == descriptor.getDependencyType()) {
        return createOptionalDependency(descriptor, requestingBeanName);
    }
    else if (ObjectFactory.class == descriptor.getDependencyType() ||
            ObjectProvider.class == descriptor.getDependencyType()) {
        return new DependencyObjectProvider(descriptor, requestingBeanName);
    }
    else if (javaxInjectProviderClass == descriptor.getDependencyType()) {
        return new Jsr330Factory().createDependencyProvider(descriptor, requestingBeanName);
    }
    else {
        Object result = getAutowireCandidateResolver().getLazyResolutionProxyIfNecessary(
                descriptor, requestingBeanName);
        if (result == null) {
            result = doResolveDependency(descriptor, requestingBeanName, autowiredBeanNames, typeConverter);
        }
        return result;
    }
}
 
 
doResolveDependency
 
 
根据工厂中定义的bean解析指定的依赖项
 
 
public Object doResolveDependency(DependencyDescriptor descriptor, @Nullable String beanName,
        @Nullable Set autowiredBeanNames, @Nullable TypeConverter typeConverter) throws BeansException {

    InjectionPoint previousInjectionPoint = ConstructorResolver.setCurrentInjectionPoint(descriptor);
    try {
        // spring第一次创建依赖的时候，会存放在shortcut，后面就不用再解析了
        Object shortcut = descriptor.resolveShortcut(this);
        if (shortcut != null) {
            return shortcut;
        }
        // 获取注入属性的类型
        Class type = descriptor.getDependencyType();
        // 处理@Value的值
        Object value = getAutowireCandidateResolver().getSuggestedValue(descriptor);
        if (value != null) {
            // 解析value
            if (value instanceof String) {
                String strVal = resolveEmbeddedValue((String) value);
                BeanDefinition bd = (beanName != null && containsBean(beanName) ?
                        getMergedBeanDefinition(beanName) : null);
                value = evaluateBeanDefinitionString(strVal, bd);
            }
            TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
            try {
                return converter.convertIfNecessary(value, type, descriptor.getTypeDescriptor());
            }
            catch (UnsupportedOperationException ex) {
                // A custom TypeConverter which does not support TypeDescriptor resolution...
                return (descriptor.getField() != null ?
                        converter.convertIfNecessary(value, type, descriptor.getField()) :
                        converter.convertIfNecessary(value, type, descriptor.getMethodParameter()));
            }
        }
        // 对数组容器的处理，
        Object multipleBeans = resolveMultipleBeans(descriptor, beanName, autowiredBeanNames, typeConverter);
        if (multipleBeans != null) {
            return multipleBeans;
        }
        // 对非数组、容器对象的处理，键值对
        Map matchingBeans = findAutowireCandidates(beanName, type, descriptor);
        if (matchingBeans.isEmpty()) {
            // 为空，且required为true，抛异常
            if (isRequired(descriptor)) {
                raiseNoMatchingBeanFound(type, descriptor.getResolvableType(), descriptor);
            }
            return null;
        }

        String autowiredBeanName;
        Object instanceCandidate;
        // 有多个的情况，筛选一个
        if (matchingBeans.size() > 1) {
            autowiredBeanName = determineAutowireCandidate(matchingBeans, descriptor);
            if (autowiredBeanName == null) {
                if (isRequired(descriptor) || !indicatesMultipleBeans(type)) {
                    return descriptor.resolveNotUnique(descriptor.getResolvableType(), matchingBeans);
                }
                else {
                    // In case of an optional Collection/Map, silently ignore a non-unique case:
                    // possibly it was meant to be an empty collection of multiple regular beans
                    // (before 4.3 in particular when we didn't even look for collection beans).
                    return null;
                }
            }
            instanceCandidate = matchingBeans.get(autowiredBeanName);
        }
        else {
            // We have exactly one match.
            // 只有一个，直接返回
            Map.Entry entry = matchingBeans.entrySet().iterator().next();
            autowiredBeanName = entry.getKey();
            instanceCandidate = entry.getValue();
        }

        if (autowiredBeanNames != null) {
            autowiredBeanNames.add(autowiredBeanName);
        }
        if (instanceCandidate instanceof Class) {
            instanceCandidate = descriptor.resolveCandidate(autowiredBeanName, type, this);
        }
        Object result = instanceCandidate;
        if (result instanceof NullBean) {
            if (isRequired(descriptor)) {
                raiseNoMatchingBeanFound(type, descriptor.getResolvableType(), descriptor);
            }
            result = null;
        }
        if (!ClassUtils.isAssignableValue(type, result)) {
            throw new BeanNotOfRequiredTypeException(autowiredBeanName, type, instanceCandidate.getClass());
        }
        return result;
    }
    finally {
        ConstructorResolver.setCurrentInjectionPoint(previousInjectionPoint);
    }
}
 
 
resolveMultipleBeans
 
 
数组容器的情况
 
 
private Object resolveMultipleBeans(DependencyDescriptor descriptor, @Nullable String beanName,
        @Nullable Set autowiredBeanNames, @Nullable TypeConverter typeConverter) {
    
    final Class type = descriptor.getDependencyType();
    
    if (descriptor instanceof StreamDependencyDescriptor) {
        Map matchingBeans = findAutowireCandidates(beanName, type, descriptor);
        if (autowiredBeanNames != null) {
            autowiredBeanNames.addAll(matchingBeans.keySet());
        }
        Stream stream = matchingBeans.keySet().stream()
                .map(name -> descriptor.resolveCandidate(name, type, this))
                .filter(bean -> !(bean instanceof NullBean));
        if (((StreamDependencyDescriptor) descriptor).isOrdered()) {
            stream = stream.sorted(adaptOrderComparator(matchingBeans));
        }
        return stream;
    }
    else if (type.isArray()) {
        // 数组的情况
        Class componentType = type.getComponentType();
        ResolvableType resolvableType = descriptor.getResolvableType();
        Class resolvedArrayType = resolvableType.resolve(type);
        if (resolvedArrayType != type) {
            componentType = resolvableType.getComponentType().resolve();
        }
        if (componentType == null) {
            return null;
        }
        Map matchingBeans = findAutowireCandidates(beanName, componentType,
                new MultiElementDescriptor(descriptor));
        if (matchingBeans.isEmpty()) {
            return null;
        }
        if (autowiredBeanNames != null) {
            autowiredBeanNames.addAll(matchingBeans.keySet());
        }
        TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
        Object result = converter.convertIfNecessary(matchingBeans.values(), resolvedArrayType);
        if (result instanceof Object[]) {
            Comparator comparator = adaptDependencyComparator(matchingBeans);
            if (comparator != null) {
                Arrays.sort((Object[]) result, comparator);
            }
        }
        return result;
    }
    else if (Collection.class.isAssignableFrom(type) && type.isInterface()) {
        // 容器的情况
        Class elementType = descriptor.getResolvableType().asCollection().resolveGeneric();
        if (elementType == null) {
            return null;
        }
        Map matchingBeans = findAutowireCandidates(beanName, elementType,
                new MultiElementDescriptor(descriptor));
        if (matchingBeans.isEmpty()) {
            return null;
        }
        if (autowiredBeanNames != null) {
            autowiredBeanNames.addAll(matchingBeans.keySet());
        }
        TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
        Object result = converter.convertIfNecessary(matchingBeans.values(), type);
        if (result instanceof List) {
            Comparator comparator = adaptDependencyComparator(matchingBeans);
            if (comparator != null) {
                ((List) result).sort(comparator);
            }
        }
        return result;
    }
    else if (Map.class == type) {
        // map的情况
        ResolvableType mapType = descriptor.getResolvableType().asMap();
        Class keyType = mapType.resolveGeneric(0);
        if (String.class != keyType) {
            return null;
        }
        Class valueType = mapType.resolveGeneric(1);
        if (valueType == null) {
            return null;
        }
        Map matchingBeans = findAutowireCandidates(beanName, valueType,
                new MultiElementDescriptor(descriptor));
        if (matchingBeans.isEmpty()) {
            return null;
        }
        if (autowiredBeanNames != null) {
            autowiredBeanNames.addAll(matchingBeans.keySet());
        }
        return matchingBeans;
    }
    else {
        return null;
    }
} 
 
isRequired
 
 
Required是否为true
 
 
private boolean isRequired(DependencyDescriptor descriptor) {
    return getAutowireCandidateResolver().isRequired(descriptor);
}
 
 
indicatesMultipleBeans
 
 
注入属性是数组或者容器
 
 
private boolean indicatesMultipleBeans(Class type) {
    return (type.isArray() || (type.isInterface() &&
            (Collection.class.isAssignableFrom(type) || Map.class.isAssignableFrom(type))));
}
 
 
adaptDependencyComparator
 
 
private Comparator adaptDependencyComparator(Map matchingBeans) {
    Comparator comparator = getDependencyComparator();
    if (comparator instanceof OrderComparator) {
        return ((OrderComparator) comparator).withSourceProvider(
                createFactoryAwareOrderSourceProvider(matchingBeans));
    }
    else {
        return comparator;
    }
} 
 
adaptOrderComparator
 
 
private Comparator adaptOrderComparator(Map matchingBeans) {
    Comparator dependencyComparator = getDependencyComparator();
    OrderComparator comparator = (dependencyComparator instanceof OrderComparator ?
            (OrderComparator) dependencyComparator : OrderComparator.INSTANCE);
    return comparator.withSourceProvider(createFactoryAwareOrderSourceProvider(matchingBeans));
} 
 
createFactoryAwareOrderSourceProvider
 
 
private OrderComparator.OrderSourceProvider createFactoryAwareOrderSourceProvider(Map beans) {
    IdentityHashMap instancesToBeanNames = new IdentityHashMap<>();
    beans.forEach((beanName, instance) -> instancesToBeanNames.put(instance, beanName));
    return new FactoryAwareOrderSourceProvider(instancesToBeanNames);
}
 
 
findAutowireCandidates
 
 
protected Map findAutowireCandidates(
        @Nullable String beanName, Class requiredType, DependencyDescriptor descriptor) {
    // 获取批评类型的beanName
    String[] candidateNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
            this, requiredType, true, descriptor.isEager());
    // 存放结果
    Map result = new LinkedHashMap<>(candidateNames.length);
    // 如果遍历的类型是指定的类型或者子类的话，报错在result
    for (Map.Entry, Object> classObjectEntry : this.resolvableDependencies.entrySet()) {
        Class autowiringType = classObjectEntry.getKey();
        if (autowiringType.isAssignableFrom(requiredType)) {
            Object autowiringValue = classObjectEntry.getValue();
            autowiringValue = AutowireUtils.resolveAutowiringValue(autowiringValue, requiredType);
            if (requiredType.isInstance(autowiringValue)) {
                result.put(ObjectUtils.identityToString(autowiringValue), autowiringValue);
                break;
            }
        }
    }
    for (String candidate : candidateNames) {
        // 如果不是自引用，且符合注入的条件
        if (!isSelfReference(beanName, candidate) && isAutowireCandidate(candidate, descriptor)) {
            addCandidateEntry(result, candidate, descriptor, requiredType);
        }
    }
    // result为空
    if (result.isEmpty()) {
        // 注入属性是数组和容器类型，对泛型检查
        boolean multiple = indicatesMultipleBeans(requiredType);
        // Consider fallback matches if the first pass failed to find anything...
        DependencyDescriptor fallbackDescriptor = descriptor.forFallbackMatch();
        for (String candidate : candidateNames) {
            if (!isSelfReference(beanName, candidate) && isAutowireCandidate(candidate, fallbackDescriptor) &&
                    (!multiple || getAutowireCandidateResolver().hasQualifier(descriptor))) {
                addCandidateEntry(result, candidate, descriptor, requiredType);
            }
        }
        // 为空，且不是数组和容器类型，添加自引用
        if (result.isEmpty() && !multiple) {
            // Consider self references as a final pass...
            // but in the case of a dependency collection, not the very same bean itself.
            for (String candidate : candidateNames) {
                if (isSelfReference(beanName, candidate) &&
                        (!(descriptor instanceof MultiElementDescriptor) || !beanName.equals(candidate)) &&
                        isAutowireCandidate(candidate, fallbackDescriptor)) {
                    addCandidateEntry(result, candidate, descriptor, requiredType);
                }
            }
        }
    }
    return result;
}
 
 
addCandidateEntry
 
 
加入到candidate，在主候选项选择之前防止早期的bean初始化。
 
 
private void addCandidateEntry(Map candidates, String candidateName,
        DependencyDescriptor descriptor, Class requiredType) {

    if (descriptor instanceof MultiElementDescriptor) {
        Object beanInstance = descriptor.resolveCandidate(candidateName, requiredType, this);
        if (!(beanInstance instanceof NullBean)) {
            candidates.put(candidateName, beanInstance);
        }
    }
    else if (containsSingleton(candidateName) || (descriptor instanceof StreamDependencyDescriptor &&
            ((StreamDependencyDescriptor) descriptor).isOrdered())) {
        Object beanInstance = descriptor.resolveCandidate(candidateName, requiredType, this);
        candidates.put(candidateName, (beanInstance instanceof NullBean ? null : beanInstance));
    }
    else {
        candidates.put(candidateName, getType(candidateName));
    }
}
 
 
determineAutowireCandidate
 
 
protected String determineAutowireCandidate(Map candidates, DependencyDescriptor descriptor) {
    Class requiredType = descriptor.getDependencyType();
    // 如果是主要的，直接返回
    String primaryCandidate = determinePrimaryCandidate(candidates, requiredType);
    if (primaryCandidate != null) {
        return primaryCandidate;
    }
    // 如果是最高级的，直接返回
    String priorityCandidate = determineHighestPriorityCandidate(candidates, requiredType);
    if (priorityCandidate != null) {
        return priorityCandidate;
    }
    // Fallback
    // 如果不是主要和最高级的
    for (Map.Entry entry : candidates.entrySet()) {
        String candidateName = entry.getKey();
        Object beanInstance = entry.getValue();
        if ((beanInstance != null && this.resolvableDependencies.containsValue(beanInstance)) ||
                matchesBeanName(candidateName, descriptor.getDependencyName())) {
            return candidateName;
        }
    }
    return null;
}
 
 
determinePrimaryCandidate
 
 
如果是主要的情况
 
 
protected String determinePrimaryCandidate(Map candidates, Class requiredType) {
    String primaryBeanName = null;
    for (Map.Entry entry : candidates.entrySet()) {
        String candidateBeanName = entry.getKey();
        Object beanInstance = entry.getValue();
        if (isPrimary(candidateBeanName, beanInstance)) {
            if (primaryBeanName != null) {
                boolean candidateLocal = containsBeanDefinition(candidateBeanName);
                boolean primaryLocal = containsBeanDefinition(primaryBeanName);
                if (candidateLocal && primaryLocal) {
                    throw new NoUniqueBeanDefinitionException(requiredType, candidates.size(),
                            "more than one 'primary' bean found among candidates: " + candidates.keySet());
                }
                else if (candidateLocal) {
                    primaryBeanName = candidateBeanName;
                }
            }
            else {
                primaryBeanName = candidateBeanName;
            }
        }
    }
    return primaryBeanName;
}
 
 
determineHighestPriorityCandidate
 
 
如果是最高级的情况
 
 
protected String determineHighestPriorityCandidate(Map candidates, Class requiredType) {
    String highestPriorityBeanName = null;
    Integer highestPriority = null;
    for (Map.Entry entry : candidates.entrySet()) {
        String candidateBeanName = entry.getKey();
        Object beanInstance = entry.getValue();
        if (beanInstance != null) {
            Integer candidatePriority = getPriority(beanInstance);
            if (candidatePriority != null) {
                if (highestPriorityBeanName != null) {
                    if (candidatePriority.equals(highestPriority)) {
                        throw new NoUniqueBeanDefinitionException(requiredType, candidates.size(),
                                "Multiple beans found with the same priority ('" + highestPriority +
                                "') among candidates: " + candidates.keySet());
                    }
                    else if (candidatePriority < highestPriority) {
                        highestPriorityBeanName = candidateBeanName;
                        highestPriority = candidatePriority;
                    }
                }
                else {
                    highestPriorityBeanName = candidateBeanName;
                    highestPriority = candidatePriority;
                }
            }
        }
    }
    return highestPriorityBeanName;
}
 
 
isPrimary
 
 
是否为主要的，即有primary
 
 
protected boolean isPrimary(String beanName, Object beanInstance) {
    if (containsBeanDefinition(beanName)) {
        return getMergedLocalBeanDefinition(beanName).isPrimary();
    }
    BeanFactory parent = getParentBeanFactory();
    return (parent instanceof DefaultListableBeanFactory &&
            ((DefaultListableBeanFactory) parent).isPrimary(beanName, beanInstance));
}
 
 
getPriority
 
 
获取优先级
 
 
protected Integer getPriority(Object beanInstance) {
    Comparator comparator = getDependencyComparator();
    if (comparator instanceof OrderComparator) {
        return ((OrderComparator) comparator).getPriority(beanInstance);
    }
    return null;
} 
 
matchesBeanName
 
 
确定给定的候选名称是否与bean名或别名匹配存储在这个bean定义中
 
 
protected boolean matchesBeanName(String beanName, @Nullable String candidateName) {
    return (candidateName != null &&
            (candidateName.equals(beanName) || ObjectUtils.containsElement(getAliases(beanName), candidateName)));
}
 
 
isSelfReference
 
 
是否自引用
 
 
private boolean isSelfReference(@Nullable String beanName, @Nullable String candidateName) {
    return (beanName != null && candidateName != null &&
            (beanName.equals(candidateName) || (containsBeanDefinition(candidateName) &&
                    beanName.equals(getMergedLocalBeanDefinition(candidateName).getFactoryBeanName()))));
}
 
 
raiseNoMatchingBeanFound
 
 
没有匹配，抛异常
 
 
private void raiseNoMatchingBeanFound(
        Class type, ResolvableType resolvableType, DependencyDescriptor descriptor) throws BeansException {

    checkBeanNotOfRequiredType(type, descriptor);

    throw new NoSuchBeanDefinitionException(resolvableType,
            "expected at least 1 bean which qualifies as autowire candidate. " +
            "Dependency annotations: " + ObjectUtils.nullSafeToString(descriptor.getAnnotations()));
}
 
 
checkBeanNotOfRequiredType
 
 
private void checkBeanNotOfRequiredType(Class type, DependencyDescriptor descriptor) {
    
    for (String beanName : this.beanDefinitionNames) {
        RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
        Class targetType = mbd.getTargetType();
        // 指定的的类型是mbd的targetType子类且符合自动注入条件
        if (targetType != null && type.isAssignableFrom(targetType) &&
                isAutowireCandidate(beanName, mbd, descriptor, getAutowireCandidateResolver())) {
            // Probably a proxy interfering with target type match -> throw meaningful exception.
            Object beanInstance = getSingleton(beanName, false);
            // 获取bean的类型
            Class beanType = (beanInstance != null && beanInstance.getClass() != NullBean.class ?
                    beanInstance.getClass() : predictBeanType(beanName, mbd));
            // 实际类型不是指定类型的子类
            if (beanType != null && !type.isAssignableFrom(beanType)) {
                throw new BeanNotOfRequiredTypeException(beanName, type, beanType);
            }
        }
    }
    // 从父类检查
    BeanFactory parent = getParentBeanFactory();
    if (parent instanceof DefaultListableBeanFactory) {
        ((DefaultListableBeanFactory) parent).checkBeanNotOfRequiredType(type, descriptor);
    }
}
 
 
createOptionalDependency
 
 
创建一个Optional的依赖
 
 
private Optional createOptionalDependency(
        DependencyDescriptor descriptor, @Nullable String beanName, final Object... args) {

    DependencyDescriptor descriptorToUse = new NestedDependencyDescriptor(descriptor) {
        @Override
        public boolean isRequired() {
            return false;
        }
        @Override
        public Object resolveCandidate(String beanName, Class requiredType, BeanFactory beanFactory) {
            return (!ObjectUtils.isEmpty(args) ? beanFactory.getBean(beanName, args) :
                    super.resolveCandidate(beanName, requiredType, beanFactory));
        }
    };
    Object result = doResolveDependency(descriptorToUse, beanName, null, null);
    return (result instanceof Optional ? (Optional) result : Optional.ofNullable(result));
}
 
 
toString
 
 
重写toString方法
 
 
public String toString() {
    StringBuilder sb = new StringBuilder(ObjectUtils.identityToString(this));
    sb.append(": defining beans [");
    sb.append(StringUtils.collectionToCommaDelimitedString(this.beanDefinitionNames));
    sb.append("]; ");
    BeanFactory parent = getParentBeanFactory();
    if (parent == null) {
        sb.append("root of factory hierarchy");
    }
    else {
        sb.append("parent: ").append(ObjectUtils.identityToString(parent));
    }
    return sb.toString();
}
 

                            
                        
                    
                    
                    

                    
                    
                    

                
                

                    
                

            
        
    
    

        
你可能感兴趣的:(源码分析,spring,java)

        

            

                
    
                    
  • Long类型前后端数据不一致
                        igotyback
前端
                        
    响应给前端的数据浏览器控制台中response中看到的Long类型的数据是正常的到前端数据不一致前后端数据类型不匹配是一个常见问题，尤其是当后端使用Java的Long类型（64位）与前端JavaScript的Number类型（最大安全整数为2^53-1，即16位）进行数据交互时，很容易出现精度丢失的问题。这是因为JavaScript中的Number类型无法安全地表示超过16位的整数。为了解决这个问
    
                    
    • 
                    
  • LocalDateTime 转 String
                        igotyback
java开发语言
                        
    importjava.time.LocalDateTime;importjava.time.format.DateTimeFormatter;publicclassMain{publicstaticvoidmain(String[]args){//获取当前时间LocalDateTimenow=LocalDateTime.now();//定义日期格式化器DateTimeFormatterformat
    
                    
    • 
                    
  • Linux下QT开发的动态库界面弹出操作（SDL2）
                        13jjyao
QT类qt开发语言sdl2linux
                        
    需求：操作系统为linux，开发框架为qt，做成需带界面的qt动态库，调用方为java等非qt程序难点：调用方为java等非qt程序，也就是说调用方肯定不带QApplication::exec()，缺少了这个，QTimer等事件和QT创建的窗口将不能弹出(包括opencv也是不能弹出)；这与qt调用本身qt库是有本质的区别的思路：1.调用方缺QApplication::exec()，那么我们在接口
    
                    
    • 
                    
  • DIV+CSS+JavaScript技术制作网页（旅游主题网页设计与制作）云南大理
                        STU学生网页设计
网页设计期末网页作业html静态网页html5期末大作业网页设计web大作业
                        
    ️精彩专栏推荐作者主页:【进入主页—获取更多源码】web前端期末大作业：【HTML5网页期末作业(1000套)】程序员有趣的告白方式：【HTML七夕情人节表白网页制作(110套)】文章目录二、网站介绍三、网站效果▶️1.视频演示2.图片演示四、网站代码HTML结构代码CSS样式代码五、更多源码二、网站介绍网站布局方面：计划采用目前主流的、能兼容各大主流浏览器、显示效果稳定的浮动网页布局结构。网站程
    
                    
    • 
                    
  • 【华为OD机试真题2023B卷 JAVA&JS】We Are A Team
                        若博豆
java算法华为javascript
                        
    华为OD2023（B卷）机试题库全覆盖，刷题指南点这里WeAreATeam时间限制：1秒|内存限制：32768K|语言限制：不限题目描述：总共有n个人在机房，每个人有一个标号（1<=标号<=n），他们分成了多个团队，需要你根据收到的m条消息判定指定的两个人是否在一个团队中，具体的：1、消息构成为：abc，整数a、b分别代
    
                    
    • 
                    
  • 关于城市旅游的HTML网页设计——(旅游风景云南 5页)HTML+CSS+JavaScript
                        二挡起步
web前端期末大作业javascripthtmlcss旅游风景
                        
    ⛵源码获取文末联系✈Web前端开发技术描述网页设计题材，DIV+CSS布局制作,HTML+CSS网页设计期末课程大作业|游景点介绍|旅游风景区|家乡介绍|等网站的设计与制作|HTML期末大学生网页设计作业，Web大学生网页HTML：结构CSS：样式在操作方面上运用了html5和css3，采用了div+css结构、表单、超链接、浮动、绝对定位、相对定位、字体样式、引用视频等基础知识JavaScrip
    
                    
    • 
                    
  • HTML网页设计制作大作业（div+css） 云南我的家乡旅游景点 带文字滚动
                        二挡起步
web前端期末大作业web设计网页规划与设计htmlcssjavascriptdreamweaver前端
                        
    Web前端开发技术描述网页设计题材，DIV+CSS布局制作,HTML+CSS网页设计期末课程大作业游景点介绍|旅游风景区|家乡介绍|等网站的设计与制作HTML期末大学生网页设计作业HTML：结构CSS：样式在操作方面上运用了html5和css3，采用了div+css结构、表单、超链接、浮动、绝对定位、相对定位、字体样式、引用视频等基础知识JavaScript：做与用户的交互行为文章目录前端学习路线
    
                    
    • 
                    
  • node.js学习
                        小猿L
node.jsnode.js学习vim
                        
    node.js学习实操及笔记温故node.js，node.js学习实操过程及笔记~node.js学习视频node.js官网node.js中文网实操笔记githubcsdn笔记为什么学node.js可以让别人访问我们编写的网页为后续的框架学习打下基础，三大框架vuereactangular离不开node.jsnode.js是什么官网：node.js是一个开源的、跨平台的运行JavaScript的运行
    
                    
    • 
                    
  • SpringBlade dict-biz/list 接口 SQL 注入漏洞
                        文章永久免费只为良心
oracle数据库
                        
    SpringBladedict-biz/list接口SQL注入漏洞POC:构造请求包查看返回包你的网址/api/blade-system/dict-biz/list?updatexml(1,concat(0x7e,md5(1),0x7e),1)=1漏洞概述在SpringBlade框架中，如果dict-biz/list接口的后台处理逻辑没有正确地对用户输入进行过滤或参数化查询（PreparedSta
    
                    
    • 
                    
  • Java 重写(Override)与重载(Overload)
                        叨唧唧的

                        
    Java重写(Override)与重载(Overload)重写(Override)重写是子类对父类的允许访问的方法的实现过程进行重新编写,返回值和形参都不能改变。即外壳不变，核心重写！重写的好处在于子类可以根据需要，定义特定于自己的行为。也就是说子类能够根据需要实现父类的方法。重写方法不能抛出新的检查异常或者比被重写方法申明更加宽泛的异常。例如：父类的一个方法申明了一个检查异常IOExceptio
    
                    
    • 
                    
  • 简单了解 JVM
                        记得开心一点啊
jvm
                        
    目录♫什么是JVM♫JVM的运行流程♫JVM运行时数据区♪虚拟机栈♪本地方法栈♪堆♪程序计数器♪方法区/元数据区♫类加载的过程♫双亲委派模型♫垃圾回收机制♫什么是JVMJVM是JavaVirtualMachine的简称，意为Java虚拟机。虚拟机是指通过软件模拟的具有完整硬件功能的、运行在一个完全隔离的环境中的完整计算机系统（如：JVM、VMwave、VirtualBox）。JVM和其他两个虚拟机
    
                    
    • 
                    
  • 1分钟解决 -bash: mvn: command not found，在Centos 7中安装Maven
                        Energet!c
开发语言
                        
    1分钟解决-bash:mvn:commandnotfound，在Centos7中安装Maven检查Java环境1下载Maven2解压Maven3配置环境变量4验证安装5常见问题与注意事项6总结检查Java环境Maven依赖Java环境，请确保系统已经安装了Java并配置了环境变量。可以通过以下命令检查：java-version如果未安装，请先安装Java。1下载Maven从官网下载：前往Apach
    
                    
    • 
                    
  • Java企业面试题3
                        马龙强_
java
                        
    1.break和continue的作用(智*图)break：用于完全退出一个循环（如for,while）或一个switch语句。当在循环体内遇到break语句时，程序会立即跳出当前循环体，继续执行循环之后的代码。continue：用于跳过当前循环体中剩余的部分，并开始下一次循环。如果是在for循环中使用continue，则会直接进行条件判断以决定是否执行下一轮循环。2.if分支语句和switch分
    
                    
    • 
                    
  • JVM、JRE和 JDK：理解Java开发的三大核心组件
                        Y雨何时停T
Javajava
                        
    Java是一门跨平台的编程语言，它的成功离不开背后强大的运行环境与开发工具的支持。在Java的生态中，JVM（Java虚拟机）、JRE（Java运行时环境）和JDK（Java开发工具包）是三个至关重要的核心组件。本文将探讨JVM、JDK和JRE的区别，帮助你更好地理解Java的运行机制。1.JVM：Java虚拟机（JavaVirtualMachine）什么是JVM？JVM，即Java虚拟机，是Ja
    
                    
    • 
                    
  • Java面试题精选：消息队列(二)
                        芒果不是芒
Java面试题精选javakafka
                        
    一、Kafka的特性1.消息持久化：消息存储在磁盘，所以消息不会丢失2.高吞吐量：可以轻松实现单机百万级别的并发3.扩展性：扩展性强，还是动态扩展4.多客户端支持：支持多种语言（Java、C、C++、GO、）5.KafkaStreams（一个天生的流处理）:在双十一或者销售大屏就会用到这种流处理。使用KafkaStreams可以快速的把销售额统计出来6.安全机制：Kafka进行生产或者消费的时候会
    
                    
    • 
                    
  • 白骑士的Java教学基础篇 2.5 控制流语句
                        白骑士所长
Java教学java开发语言
                        
    欢迎继续学习Java编程的基础篇！在前面的章节中，我们了解了Java的变量、数据类型和运算符。接下来，我们将探讨Java中的控制流语句。控制流语句用于控制程序的执行顺序，使我们能够根据特定条件执行不同的代码块，或重复执行某段代码。这是编写复杂程序的基础。通过学习这一节内容，你将掌握如何使用条件语句和循环语句来编写更加灵活和高效的代码。条件语句条件语句用于根据条件的真假来执行不同的代码块。if语句‘
    
                    
    • 
                    
  • python语法——三目运算符
                        HappyRocking
pythonpython三目运算符
                        
    在java中，有三目运算符，如：intc=(a>b)?a:b表示c取两者中的较大值。但是在python，不能直接这样使用，估计是因为冒号在python有分行的关键作用。那么在python中，如何实现类似功能呢？可以使用ifelse语句，也是一行可以完成，格式为：aifbelsec表示如果b为True，则表达式等于a，否则等于c。如：c=(aif(a>b)elseb)同样是完成了取最大值的功能。
    
                    
    • 
                    
  • spring如何整合druid连接池？
                        惜.己
springspringjunit数据库javaidea后端xml
                        
    目录spring整合druid连接池1.新建maven项目2.新建mavenModule3.导入相关依赖4.配置log4j2.xml5.配置druid.xml1)xml中如何引入properties2)下面是配置文件6.准备jdbc.propertiesJDBC配置项解释7.配置druid8.测试spring整合druid连接池1.新建maven项目打开IDE（比如IntelliJIDEA,Ecl
    
                    
    • 
                    
  • ArrayList 源码解析
                        程序猿进阶
Java基础ArrayListListjava面试性能优化架构设计idea
                        
    ArrayList是Java集合框架中的一个动态数组实现，提供了可变大小的数组功能。它继承自AbstractList并实现了List接口，是顺序容器，即元素存放的数据与放进去的顺序相同，允许放入null元素，底层通过数组实现。除该类未实现同步外，其余跟Vector大致相同。每个ArrayList都有一个容量capacity，表示底层数组的实际大小，容器内存储元素的个数不能多于当前容量。当向容器中添
    
                    
    • 
                    
  • Java爬虫框架（一）--架构设计
                        狼图腾-狼之传说
java框架java任务html解析器存储电子商务
                        
    一、架构图那里搜网络爬虫框架主要针对电子商务网站进行数据爬取，分析，存储，索引。爬虫：爬虫负责爬取，解析，处理电子商务网站的网页的内容数据库：存储商品信息索引：商品的全文搜索索引Task队列：需要爬取的网页列表Visited表：已经爬取过的网页列表爬虫监控平台：web平台可以启动，停止爬虫，管理爬虫，task队列，visited表。二、爬虫1.流程1)Scheduler启动爬虫器，TaskMast
    
                    
    • 
                    
  • Java：爬虫框架
                        dingcho
Javajava爬虫
                        
    一、ApacheNutch2【参考地址】Nutch是一个开源Java实现的搜索引擎。它提供了我们运行自己的搜索引擎所需的全部工具。包括全文搜索和Web爬虫。Nutch致力于让每个人能很容易,同时花费很少就可以配置世界一流的Web搜索引擎.为了完成这一宏伟的目标,Nutch必须能够做到:每个月取几十亿网页为这些网页维护一个索引对索引文件进行每秒上千次的搜索提供高质量的搜索结果简单来说Nutch支持分
    
                    
    • 
                    
  • python怎么将png转为tif_png转tif
                        weixin_39977276

                        
    发国外的文章要求图片是tif，cmyk色彩空间的。大小尺寸还有要求。比如网上大神多，找到了一段代码，感谢！https://www.jianshu.com/p/ec2af4311f56https://github.com/KevinZc007/image2Tifimportjava.awt.image.BufferedImage;importjava.io.File;importjava.io.Fi
    
                    
    • 
                    
  • SpringCloudAlibaba—Sentinel(限流)
                        菜鸟爪哇

                        
    前言：自己在学习过程的记录，借鉴别人文章，记录自己实现的步骤。借鉴文章：https://blog.csdn.net/u014494148/article/details/105484410Sentinel介绍Sentinel诞生于阿里巴巴，其主要目标是流量控制和服务熔断。Sentinel是通过限制并发线程的数量（即信号隔离）来减少不稳定资源的影响，而不是使用线程池，省去了线程切换的性能开销。当资源
    
                    
    • 
                    
  • springboot+vue项目实战一-创建SpringBoot简单项目
                        苹果酱0567
面试题汇总与解析springboot后端java中间件开发语言
                        
    这段时间抽空给女朋友搭建一个个人博客，想着记录一下建站的过程，就当做笔记吧。虽然复制zjblog只要一个小时就可以搞定一个网站，或者用cms系统，三四个小时就可以做出一个前后台都有的网站，而且想做成啥样也都行。但是就是要从新做，自己做的意义不一样，更何况，俺就是专门干这个的，嘿嘿嘿要做一个网站，而且从零开始，首先呢就是技术选型了，经过一番思量决定选择-SpringBoot做后端，前端使用Vue做一
    
                    
    • 
                    
  • JavaScript 中，深拷贝（Deep Copy）和浅拷贝（Shallow Copy）
                        跳房子的前端
前端面试javascript开发语言ecmascript
                        
    在JavaScript中，深拷贝（DeepCopy）和浅拷贝（ShallowCopy）是用于复制对象或数组的两种不同方法。了解它们的区别和应用场景对于避免潜在的bugs和高效地处理数据非常重要。以下是对深拷贝和浅拷贝的详细解释，包括它们的概念、用途、优缺点以及实现方式。1.浅拷贝（ShallowCopy）概念定义：浅拷贝是指创建一个新的对象或数组，其中包含了原对象或数组的基本数据类型的值和对引用数
    
                    
    • 
                    
  • JAVA·一个简单的登录窗口
                        MortalTom
java开发语言学习
                        
    文章目录概要整体架构流程技术名词解释技术细节资源概要JavaSwing是Java基础类库的一部分，主要用于开发图形用户界面（GUI）程序整体架构流程新建项目，导入sql.jar包（链接放在了文末），编译项目并运行技术名词解释一、特点丰富的组件提供了多种可视化组件，如按钮（JButton）、文本框（JTextField）、标签（JLabel）、下拉列表（JComboBox）等，可以满足不同的界面设计
    
                    
    • 
                    
  • Spring MVC 全面指南：从入门到精通的详细解析
                        一杯梅子酱
技术栈学习springmvcjava
                        
    引言：SpringMVC，作为Spring框架的一个重要模块，为构建Web应用提供了强大的功能和灵活性。无论是初学者还是有一定经验的开发者，掌握SpringMVC都将显著提升你的Web开发技能。本文旨在为初学者提供一个全面且易于理解的学习路径，通过详细的知识点分析和实际案例，帮助你快速上手SpringMVC，让学习过程既深刻又高效。一、SpringMVC简介1.1什么是SpringMVC？Spri
    
                    
    • 
                    
  • Spring Boot中实现跨域请求
                        BABA8891
springboot后端java
                        
    在SpringBoot中实现跨域请求（CORS，Cross-OriginResourceSharing）可以通过多种方式，以下是几种常见的方法：1.使用@CrossOrigin注解在SpringBoot中，你可以在控制器或者具体的请求处理方法上使用@CrossOrigin注解来允许跨域请求。在控制器上应用：importorg.springframework.web.bind.annotation.
    
                    
    • 
                    
  • WebMagic：强大的Java爬虫框架解析与实战
                        Aaron_945
Javajava爬虫开发语言
                        
    文章目录引言官网链接WebMagic原理概述基础使用1.添加依赖2.编写PageProcessor高级使用1.自定义Pipeline2.分布式抓取优点结论引言在大数据时代，网络爬虫作为数据收集的重要工具，扮演着不可或缺的角色。Java作为一门广泛使用的编程语言，在爬虫开发领域也有其独特的优势。WebMagic是一个开源的Java爬虫框架，它提供了简单灵活的API，支持多线程、分布式抓取，以及丰富的
    
                    
    • 
                    
  • 博客网站制作教程
                        2401_85194651
javamaven
                        
    首先就是技术框架：后端：Java+SpringBoot数据库：MySQL前端：Vue.js数据库连接：JPA(JavaPersistenceAPI)1.项目结构blog-app/├──backend/│├──src/main/java/com/example/blogapp/││├──BlogApplication.java││├──config/│││└──DatabaseConfig.java
    
                    
    • 
                                
  • Dom
                                    周华华
JavaScripthtml
                                    
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml&q
    
                                
    • 
                                
  • 【Spark九十六】RDD API之combineByKey
                                    bit1129
spark
                                    
    1. combineByKey函数的运行机制 
  
RDD提供了很多针对元素类型为(K,V)的API，这些API封装在PairRDDFunctions类中，通过Scala隐式转换使用。这些API实现上是借助于combineByKey实现的。combineByKey函数本身也是RDD开放给Spark开发人员使用的API之一 
  
首先看一下combineByKey的方法说明：
    
                                
    • 
                                
  • msyql设置密码报错：ERROR 1372 (HY000): 解决方法详解
                                    daizj
mysql设置密码
                                    
    MySql给用户设置权限同时指定访问密码时，会提示如下错误： 
ERROR 1372 (HY000): Password hash should be a 41-digit hexadecimal number； 
  
问题原因：你输入的密码是明文。不允许这么输入。 
  
解决办法：用select password('你想输入的密码');查询出你的密码对应的字符串， 
然后
    
                                
    • 
                                
  • 路漫漫其修远兮 吾将上下而求索
                                    周凡杨
学习 思索
                                    
    王国维在他的《人间词话》中曾经概括了为学的三种境界古今之成大事业、大学问者，罔不经过三种之境界。“昨夜西风凋碧树。独上高楼，望尽天涯路。”此第一境界也。“衣带渐宽终不悔，为伊消得人憔悴。”此第二境界也。“众里寻他千百度，蓦然回首，那人却在灯火阑珊处。”此第三境界也。学习技术，这也是你必须经历的三种境界。第一层境界是说，学习的路是漫漫的，你必须做好充分的思想准备，如果半途而废还不如不要开始。这里，注
    
                                
    • 
                                
  • Hadoop(二)对话单的操作
                                    朱辉辉33
hadoop
                                    
    Debug： 
 
1、 
 
A = LOAD '/user/hue/task.txt' USING PigStorage(' ') 
AS (col1,col2,col3); 
DUMP A; 
 
//输出结果前几行示例： 
(>ggsnPDPRecord(21),,) 
(-->recordType(0),,) 
(-->networkInitiation(1),,) 

    
                                
    • 
                                
  • web报表工具FineReport常用函数的用法总结（日期和时间函数）
                                    老A不折腾
finereport报表工具web开发
                                    
    web报表工具FineReport常用函数的用法总结（日期和时间函数） 
  
说明：凡函数中以日期作为参数因子的，其中日期的形式都必须是yy/mm/dd。而且必须用英文环境下双引号(" ")引用。 
  
DATE 
DATE(year,month,day):返回一个表示某一特定日期的系列数。 
Year:代表年，可为一到四位数。 
Month:代表月份。
    
                                
    • 
                                
  • c++ 宏定义中的##操作符
                                    墙头上一根草
C++
                                    
    #与##在宏定义中的--宏展开 #include <stdio.h> #define f(a,b) a##b #define g(a)   #a #define h(a) g(a) int main() {       &nbs
    
                                
    • 
                                
  • 分析Spring源代码之，DI的实现
                                    aijuans
springDI现源代码
                                    
    (转) 
   
分析Spring源代码之，DI的实现  
2012/1/3 by tony 
                接着上次的讲，以下这个sample    
[java]  
view plain 
copy 
print 

    
                                
    • 
                                
  • for循环的进化
                                    alxw4616
JavaScript
                                    
    // for循环的进化
// 菜鸟
for (var i = 0; i < Things.length ; i++) {
	// Things[i]
}

// 老鸟
for (var i = 0, len = Things.length; i < len; i++) {
	// Things[i]
}

// 大师
for (var i = Things.le
    
                                
    • 
                                
  • 网络编程Socket和ServerSocket简单的使用
                                    百合不是茶
网络编程基础IP地址端口
                                    
      
网络编程;TCP/IP协议 
  
网络:实现计算机之间的信息共享,数据资源的交换 
  
协议:数据交换需要遵守的一种协议,按照约定的数据格式等写出去 
  
端口:用于计算机之间的通信 
     每运行一个程序，系统会分配一个编号给该程序，作为和外界交换数据的唯一标识 
0~65535 
  
查看被使用的
    
                                
    • 
                                
  • JDK1.5 生产消费者
                                    bijian1013
javathread生产消费者java多线程
                                    
    ArrayBlockingQueue： 
       一个由数组支持的有界阻塞队列。此队列按 FIFO（先进先出）原则对元素进行排序。队列的头部 是在队列中存在时间最长的元素。队列的尾部 是在队列中存在时间最短的元素。新元素插入到队列的尾部，队列检索操作则是从队列头部开始获得元素。 
ArrayBlockingQueue的常用方法： 

    
                                
    • 
                                
  • JAVA版身份证获取性别、出生日期及年龄
                                    bijian1013
java性别出生日期年龄
                                    
            工作中需要根据身份证获取性别、出生日期及年龄，且要还要支持15位长度的身份证号码，网上搜索了一下，经过测试好像多少存在点问题，干脆自已写一个。 
CertificateNo.java 
package com.bijian.study;

import java.util.Calendar;
import 
    
                                
    • 
                                
  • 【Java范型六】范型与枚举
                                    bit1129
java
                                    
    首先，枚举类型的定义不能带有类型参数，所以，不能把枚举类型定义为范型枚举类，例如下面的枚举类定义是有编译错的 
  
public enum EnumGenerics<T> { //编译错，提示枚举不能带有范型参数
    OK, ERROR;
    public <T> T get(T type) {
        return null;
    
    
                                
    • 
                                
  • 【Nginx五】Nginx常用日志格式含义
                                    bit1129
nginx
                                    
    1. log_format 
1.1 log_format指令用于指定日志的格式，格式： 
  
log_format name(格式名称) type(格式样式) 
  
1.2 如下是一个常用的Nginx日志格式： 
  
log_format      main    '[$time_local]|$request_time|$status|$body_bytes
    
                                
    • 
                                
  • Lua 语言 15 分钟快速入门
                                    ronin47
lua 基础
                                    
    -
- 
单行注释   
-
-
[[   
    
[多行注释]   
-
-
]]       
-
-
-
-
-
-
-
-
-
-   
- 
1. 
变量 & 控制流   
-
-
-
-
-
-
-
-
-
-   
num 
= 
23 
-
- 
数字都是双精度   
str 
= 
'aspythonstring' 

    
                                
    • 
                                
  • java-35.求一个矩阵中最大的二维矩阵 ( 元素和最大 )
                                    bylijinnan
java
                                    
    the idea is from: 
http://blog.csdn.net/zhanxinhang/article/details/6731134 
 


public class MaxSubMatrix {

	/**see http://blog.csdn.net/zhanxinhang/article/details/6731134
	 * Q35
求一个矩阵中最大的二维
    
                                
    • 
                                
  • mongoDB文档型数据库特点
                                    开窍的石头
mongoDB文档型数据库特点
                                    
    MongoDD: 文档型数据库存储的是Bson文档-->json的二进制 
 
特点：内部是执行引擎是js解释器，把文档转成Bson结构，在查询时转换成js对象。 
 
mongoDB传统型数据库对比 
   传统类型数据库：结构化数据，定好了表结构后每一个内容符合表结构的。也就是说每一行每一列的数据都是一样的 
   文档型数据库：不用定好数据结构，
    
                                
    • 
                                
  • [毕业季节]欢迎广大毕业生加入JAVA程序员的行列
                                    comsci
java
                                    
     
    一年一度的毕业季来临了。。。。。。。。 
 
     正在投简历的学弟学妹们。。。如果觉得学校推荐的单位和公司不适合自己的兴趣和专业，可以考虑来我们软件行业，做一名职业程序员。。。 
 
     软件行业的开发工具中，对初学者最友好的就是JAVA语言了，网络上不仅仅有大量的
    
                                
    • 
                                
  • PHP操作Excel – PHPExcel 基本用法详解
                                    cuiyadll
PHPExcel
                                    
    导出excel属性设置//Include classrequire_once('Classes/PHPExcel.php');require_once('Classes/PHPExcel/Writer/Excel2007.php');$objPHPExcel = new PHPExcel();//Set properties 设置文件属性$objPHPExcel->getProperties
    
                                
    • 
                                
  • IBM Webshpere MQ Client User Issue (MCAUSER)
                                    darrenzhu
IBMjmsuserMQMCAUSER
                                    
    IBM MQ JMS Client去连接远端MQ Server的时候，需要提供User和Password吗？ 
答案是根据情况而定，取决于所定义的Channel里面的属性Message channel agent user identifier (MCAUSER)的设置。 
 
 
http://stackoverflow.com/questions/20209429/how-mca-user-i
    
                                
    • 
                                
  • 网线的接法
                                    dcj3sjt126com

                                    
    一、PC连HUB (直连线)A端：（标准568B）：白橙，橙，白绿，蓝，白蓝，绿，白棕，棕。 B端：（标准568B）：白橙，橙，白绿，蓝，白蓝，绿，白棕，棕。 二、PC连PC （交叉线）A端：(568A)： 白绿，绿，白橙，蓝，白蓝，橙，白棕，棕； B端：（标准568B）：白橙，橙，白绿，蓝，白蓝，绿，白棕，棕。 三、HUB连HUB&nb
    
                                
    • 
                                
  • Vimium插件让键盘党像操作Vim一样操作Chrome
                                    dcj3sjt126com
chromevim
                                    
    什么是键盘党？ 
 
 键盘党是指尽可能将所有电脑操作用键盘来完成，而不去动鼠标的人。鼠标应该说是新手们的最爱，很直观，指哪点哪，很听话！不过常常使用电脑的人，如果一直使用鼠标的话，手会发酸，因为操作鼠标的时候，手臂不是在一个自然的状态，臂肌会处于绷紧状态。而使用键盘则双手是放松状态，只有手指在动。而且尽量少的从鼠标移动到键盘来回操作，也省不少事。 
 在chrome里安装 vimium 插件 

    
                                
    • 
                                
  • MongoDB查询（2）——数组查询[六]
                                    eksliang
mongodbMongoDB查询数组
                                    
    MongoDB查询数组 
转载请出自出处：http://eksliang.iteye.com/blog/2177292 一、概述 
 MongoDB查询数组与查询标量值是一样的，例如，有一个水果列表，如下所示： 
> db.food.find()
{ "_id" : "001", "fruits" : [ "苹
    
                                
    • 
                                
  • cordova读写文件（1）
                                    gundumw100
JavaScriptCordova
                                    
    使用cordova可以很方便的在手机sdcard中读写文件。 
 
首先需要安装cordova插件：file 
命令为： 
 
cordova plugin add org.apache.cordova.file 
 
然后就可以读写文件了，这里我先是写入一个文件，具体的JS代码为： 
 


var datas=null;//datas need write
var directory=&
    
                                
    • 
                                
  • HTML5 FormData 进行文件jquery ajax 上传 到又拍云
                                    ileson
jqueryAjaxhtml5FormData
                                    
    html5 新东西：FormData  可以提交二进制数据。 
 
 
页面test.html 
 

<!DOCTYPE>
<html>
<head>
<title> formdata file jquery ajax upload</title>
</head>

<body>
<
    
                                
    • 
                                
  • swift appearanceWhenContainedIn:(version1.2 xcode6.4)
                                    啸笑天
version
                                    
      
swift1.2中没有oc中对应的方法： 
+ (instancetype)appearanceWhenContainedIn:(Class <UIAppearanceContainer>)ContainerClass, ... NS_REQUIRES_NIL_TERMINATION; 
 解决方法： 
在swift项目中新建oc类如下： 
#import &
    
                                
    • 
                                
  • java实现SMTP邮件服务器
                                    macroli
java编程
                                    
    电子邮件传递可以由多种协议来实现。目前，在Internet 网上最流行的三种电子邮件协议是SMTP、POP3 和 IMAP，下面分别简单介绍。 
　　◆ SMTP 协议 
　　简单邮件传输协议(Simple Mail Transfer Protocol,SMTP)是一个运行在TCP/IP之上的协议，用它发送和接收电子邮件。SMTP 服务器在默认端口25上监听。SMTP客户使用一组简单的、基于文本的
    
                                
    • 
                                
  • mongodb group by having where 查询sql
                                    qiaolevip
每天进步一点点学习永无止境mongo纵观千象
                                    
    SELECT cust_id,
       SUM(price) as total
FROM orders
WHERE status = 'A'
GROUP BY cust_id
HAVING total > 250

db.orders.aggregate( [
   { $match: { status: 'A' } },
   {
     $group: {

    
                                
    • 
                                
  • Struts2 Pojo（六）
                                    Luob.
POJOstrust2
                                    
    注意：附件中有完整案例 
1.采用POJO对象的方法进行赋值和传值 
2.web配置 
 

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee&q
    
                                
    • 
                                
  • struts2步骤
                                    wuai
struts
                                    
    1、添加jar包 
2、在web.xml中配置过滤器 
 <filter> 
       <filter-name>struts2</filter-name> 
       <filter-class>org.apache.st
    
                                
    •