//创建一个注解形式的配置类
@Configuration//标记这个类为注解类==配置文件
public class UserConfig {
@Bean
public User user() {
return new User();
}
}
//测试
public class Test {
public static void main(String[] args) {
//加载配置文件并创建容器
ConfigurableApplicationContext context = new AnnotationConfigApplicationContext(UserConfig.class);
User user = (User) context.getBean("user");
System.out.println(user);
}
}
//创建一个读取注解的Bean定义读取器，并将其设置到容器中
private final AnnotatedBeanDefinitionReader reader;
//创建一个扫描指定类路径中注解Bean定义的扫描器，并将其设置到容器中
private final ClassPathBeanDefinitionScanner scanner;
public AnnotationConfigApplicationContext() {
1..... this.reader = new AnnotatedBeanDefinitionReader(this);
2..... this.scanner = new ClassPathBeanDefinitionScanner(this);
}
(1)1所处的行最终会执行
public AnnotatedBeanDefinitionReader(BeanDefinitionRegistry registry, Environment environment) {
Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
Assert.notNull(environment, "Environment must not be null");
//interface for registries that hold bean definitions
this.registry = registry;
//Internal class used to evaluate {@link Conditional} annotations.
this.conditionEvaluator = new ConditionEvaluator(registry, environment, null);
AnnotationConfigUtils.registerAnnotationConfigProcessors(this.registry);
}
(2)2所处的行最终会执行
public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry, boolean useDefaultFilters, Environment environment) {
super(useDefaultFilters, environment);
Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
this.registry = registry;
// Determine ResourceLoader to use.
if (this.registry instanceof ResourceLoader) {
setResourceLoader((ResourceLoader) this.registry);
}
}
3、register(annotatedClasses)方法
主要利用AnnotatedBeanDefinitionReader对注解bean进行解析并进行注册
1、AnnotationConfigApplicationContext.register
public void register(Class... annotatedClasses) {
Assert.notEmpty(annotatedClasses, "At least one annotated class must be specified");
this.reader.register(annotatedClasses);
}
2、AnnotatedBeanDefinitionReader.register
public void register(Class... annotatedClasses) {
for (Class annotatedClass : annotatedClasses) {
registerBean(annotatedClass);
}
}
3、AnnotatedBeanDefinitionReader.registerBean
public void registerBean(Class annotatedClass, String name,
@SuppressWarnings("unchecked") Class... qualifiers) {
//该类继承GenericBeanDefinition并实现AnnotatedBeanDefinition，
//AnnotatedGenericBeanDefinition 描述了一个注解bean实例，它具有属性值，构造函数参数值。
AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass);
//根据{@code @Conditional}注释确定是否应跳过某个项目
if (this.conditionEvaluator.shouldSkip(abd.getMetadata())) {
return;
}
//ScopeMetadata 描述了一个Spring管理的bean，包括范围名称和范围的代理行为范围的特点。(也就是spring的作用域）
ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(abd);
abd.setScope(scopeMetadata.getScopeName());
//获取传入注解配置类的bean
String beanName = (name != null ? name : this.beanNameGenerator.generateBeanName(abd, this.registry));
//处理该注解bean上的一些其他注解属性，比如@lazy，@Primary等注解
//有的话加入到AnnotatedGenericBeanDefinition 中
AnnotationConfigUtils.processCommonDefinitionAnnotations(abd);
//@qualifiers注解
if (qualifiers != null) {
for (Class qualifier : qualifiers) {
if (Primary.class == qualifier) {
abd.setPrimary(true);
}
else if (Lazy.class == qualifier) {
abd.setLazyInit(true);
}
else {
abd.addQualifier(new AutowireCandidateQualifier(qualifier));
}
}
}
//BeanDefinitionHolder拥有名称和别名的BeanDefinition的持有者。可以注册为内部bean的占位符。
BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName);
definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
//在BeanDefinitionRegistry中注册相应的获取的bean，definitionHolder.getBeanName()作为beanName
//definitionHolder.getBeanDefinition()作为value，如果有别名还要进行别名注册
BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);
}
public static void registerBeanPostProcessors(
ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {
//1、获取所有的 BeanPostProcessor（其实后置处理器都默认可以通过PriorityOrdered、Ordered接口来执行优先级）
String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);
// Register BeanPostProcessorChecker that logs an info message when
// a bean is created during BeanPostProcessor instantiation, i.e. when
// a bean is not eligible for getting processed by all BeanPostProcessors.
int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));
List priorityOrderedPostProcessors = new ArrayList();
List internalPostProcessors = new ArrayList();
List orderedPostProcessorNames = new ArrayList();
List nonOrderedPostProcessorNames = new ArrayList();
for (String ppName : postProcessorNames) {
if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
priorityOrderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
orderedPostProcessorNames.add(ppName);
}
else {
nonOrderedPostProcessorNames.add(ppName);
}
}
//2、先注册PriorityOrdered优先级接口的BeanPostProcessor
sortPostProcessors(beanFactory, priorityOrderedPostProcessors);
registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);
//3、再注册Ordered接口的
List orderedPostProcessors = new ArrayList();
for (String ppName : orderedPostProcessorNames) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
orderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
sortPostProcessors(beanFactory, orderedPostProcessors);
registerBeanPostProcessors(beanFactory, orderedPostProcessors);
//4、最后注册没有实现任何优先级接口的
List nonOrderedPostProcessors = new ArrayList();
for (String ppName : nonOrderedPostProcessorNames) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
nonOrderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);
//5、最终注册 internal BeanPostProcessors.（比如MergedBeanDefinitionPostProcessor）
sortPostProcessors(beanFactory, internalPostProcessors);
ApplicationListenerDetector
registerBeanPostProcessors(beanFactory, internalPostProcessors);
//6、在Bean创建完成后检查是否是ApplicationListener，如果是注册一个
beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
}
7、初始化MessageSource组件（做国际化功能；消息绑定，消息解析）
protected void initMessageSource() {
//1、获取BeanFactory
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
//2、看容器中是否有id为messageSource的，类型是MessageSource的组件，如果有赋值给messageSource，如果没有自己创建一个DelegatingMessageSource
if (beanFactory.containsLocalBean(MESSAGE_SOURCE_BEAN_NAME)) {
this.messageSource = beanFactory.getBean(MESSAGE_SOURCE_BEAN_NAME, MessageSource.class);
// Make MessageSource aware of parent MessageSource.
if (this.parent != null && this.messageSource instanceof HierarchicalMessageSource) {
HierarchicalMessageSource hms = (HierarchicalMessageSource) this.messageSource;
if (hms.getParentMessageSource() == null) {
// Only set parent context as parent MessageSource if no parent MessageSource
// registered already.
hms.setParentMessageSource(getInternalParentMessageSource());
}
}
if (logger.isDebugEnabled()) {
logger.debug("Using MessageSource [" + this.messageSource + "]");
}
}
else {
// Use empty MessageSource to be able to accept getMessage calls.
DelegatingMessageSource dms = new DelegatingMessageSource();
dms.setParentMessageSource(getInternalParentMessageSource());
this.messageSource = dms;
//3、把创建好的MessageSource注册在容器中，以后获取国际化配置文件的值的时候，可以自动注入MessageSource； beanFactory.registerSingleton(MESSAGE_SOURCE_BEAN_NAME, this.messageSource);
if (logger.isDebugEnabled()) {
logger.debug("Unable to locate MessageSource with name '" + MESSAGE_SOURCE_BEAN_NAME +
"': using default [" + this.messageSource + "]");
}
}
}
8、初始化事件派发器
protected void initApplicationEventMulticaster() {
//1、获取BeanFactory
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
//2、从BeanFactory中获取applicationEventMulticaster的ApplicationEventMulticaster；
if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {
this.applicationEventMulticaster =
beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);
if (logger.isDebugEnabled()) {
logger.debug("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]");
}
}
else {
//3、如果上一步没有配置；创建一个SimpleApplicationEventMulticaster
this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);
//4、将创建的ApplicationEventMulticaster添加到BeanFactory中，以后其他组件直接自动注入 beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);
if (logger.isDebugEnabled()) {
logger.debug("Unable to locate ApplicationEventMulticaster with name '" +
APPLICATION_EVENT_MULTICASTER_BEAN_NAME +
"': using default [" + this.applicationEventMulticaster + "]");
}
}
}
#!/bin/bash
#
# Script to start LVS DR real server.
# description: LVS DR real server
#
#. /etc/rc.d/init.d/functions
VIP=10.10.6.252
host='/bin/hostname'
case "$1" in
sta
大多数java开发者使用的都是eclipse，今天感兴趣去eclipse官网搜了一下eclipse.ini的配置，供大家参考，我会把关键的部分给大家用中文解释一下。还是推荐有问题不会直接搜谷歌，看官方文档，这样我们会知道问题的真面目是什么，对问题也有一个全面清晰的认识。
Overview
1、Eclipse.ini的作用
Eclipse startup is controlled by th
import java.util.Arrays;
/**
* 最早是在陈利人老师的微博看到这道题：
* #面试题#An array with n elements which is K most sorted，就是每个element的初始位置和它最终的排序后的位置的距离不超过常数K
* 设计一个排序算法。It should be faster than O(n*lgn)。
原网页被墙，放这里备用。 MySQLdb User's Guide
Contents
Introduction
Installation
_mysql
MySQL C API translation
MySQL C API function mapping
Some _mysql examples
MySQLdb
