Spring Bean的属性赋值和注入

  

3 Spring Bean的属性赋值和注入

3.1 @Value

<context:property-placeholder location="classpath:/person.properties"/>
<bean id="person" class="domain.Person" init-method="" destroy-method="">
        <property name="age" value="1">property>
        <property name="name" value="zhangsan">property>
        <property name="addres" value="${address}">property>
bean>

1、创建person.propertie文件

person.address='xxx'

2、实体类

public class Person {

    @Value("zhangsan")
    private String name;

    //写Spring的表达式
    @Value("#{4+5}")
    private int age;

    @Value("${person.address}")
    private String address;

	//省略setter/getter/construct
	
    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", address='" + address + '\'' +
                '}';
    }
}

3、配置类

//读取外部配置文件中的 K/V 保存到运行的环境变量中
@PropertySource("classpath:/person.properties")
@Configuration
public class PropertyConfig {

    @Bean
    public Person person(){
        return new Person();
    }
}

4、测试类

public class PropertyTest {

    @Test
    public void test1(){
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(PropertyConfig.class);
        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        for (String s : beanDefinitionNames) {
            System.out.println(s);
        }
        Person person = (Person) applicationContext.getBean("person");
        System.out.println(person);

        Environment environment = applicationContext.getEnvironment();
        String address = environment.getProperty("person.address");
        System.out.println(address);

    }


}

5、结果

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
propertyConfig
person
Person{name='zhangsan', age=9, address=''xxx''}
'xxx'

Process finished with exit code 0

3.2 @AutoWired | @Qualifier | @Primary

自动装配：Spring利用依赖注入（DI）,完成对IOC容器中各个组件的依赖关系赋值

@Controller
public class BookController {

    @Autowired
    BookService bookService;

    @Override
    public String toString() {
        return "BookController{" +
                "bookService=" + bookService +
                '}';
    }
}

@Service
public class BookService {

    @Autowired
    BookDao bookDao;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao +
                '}';
    }
}

@Repository
public class BookDao {

    String name = "01";

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "BookDao{" +
                "name='" + name + '\'' +
                '}';
    }
}

@ComponentScan({"auto"})
@Configuration
public class AutoConfig {

    @Bean("bookDao2")
    public BookDao bookDao(){
        BookDao bookDao = new BookDao();
        bookDao.setName("2");
        return bookDao;
    }
}

public class AutoTest {
    
    @Test
    public void test1() {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(AutoConfig.class);
        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        for (String s : beanDefinitionNames) {
            System.out.println(s);
        }
        System.out.println("------");
        BookService bookService = (BookService) applicationContext.getBean("bookService");
        System.out.println(bookService.toString());
    }
}

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
autoConfig
bookController
bookDao
bookService
bookDao2
------
BookService{bookDao=BookDao{name='01'}}

Process finished with exit code 0

@AutoWired 是按照类型进行注入，如果存在两个相同类型的组件、则以属性的名称作为组件的id去容器中查找

@Service
public class BookService {

    @Autowired
    BookDao bookDao2;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao2 +
                '}';
    }
}

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
autoConfig
bookController
bookDao
bookService
bookDao2
------
BookService{bookDao=BookDao{name='2'}}

Process finished with exit code 0

有时候属性名虽然写的是bookDao2 但是还是想要为该属性注入bookDao1，这时就需要使用 @Qualifier 注解

@Service
public class BookService {

    @Qualifier("bookDao")
    @Autowired
    BookDao bookDao2;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao2 +
                '}';
    }
}

autoConfig
bookController
bookDao
bookService
bookDao2
------
BookService{bookDao=BookDao{name='01'}}

Process finished with exit code 0

自动装配默认一定要将属性赋值，没有就会报错

//@Repository
public class BookDao {
	//省略
}

@ComponentScan({"auto"})
@Configuration
public class AutoConfig {

    //@Bean("bookDao2")
    public BookDao bookDao(){
        BookDao bookDao = new BookDao();
        bookDao.setName("2");
        return bookDao;
    }
}

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'auto.BookDao' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Qualifier(value=bookDao), @org.springframework.beans.factory.annotation.Autowired(required=true)}
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
	... 52 more


Process finished with exit code -

如果该属性不需要一定装配、使用 required 属性指定

@Service
public class BookService {

    @Qualifier("bookDao")
    @Autowired(required = false)
    BookDao bookDao2;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao2 +
                '}';
    }
}

autoConfig
bookController
bookService
------
BookService{bookDao=null}

Process finished with exit code 0

@Primary：让Spring进行自动装配的时候默认使用首选的bean

@Repository
public class BookDao {

    String name = "01";

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "BookDao{" +
                "name='" + name + '\'' +
                '}';
    }
}

@Service
public class BookService {

    
    @Autowired
    BookDao bookDao;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao +
                '}';
    }
}

@ComponentScan({"auto"})
@Configuration
public class AutoConfig {

    @Primary
    @Bean("bookDao2")
    public BookDao bookDao(){
        BookDao bookDao = new BookDao();
        bookDao.setName("2");
        return bookDao;
    }
}

autoConfig
bookController
bookDao
bookService
bookDao2
------
BookService{bookDao=BookDao{name='2'}}

Process finished with exit code 0

如果使用了 @ Primary之后再使用 @Qualifier 之后，以 @Qualifier指定的为准

3.3 @Resource | @Inject

Spring还支持@Resource（JSR250） | @Inject（JSR330）都是Java的注解
@Resource默认是按照名称进行注入，没有支持@Primary和@Autowire(require = false)的功能

@Service
public class BookService {


    @Resource(name = "bookDao")
    BookDao bookDao;

    @Override
    public String toString() {
        return "BookService{" +
                "bookDao=" + bookDao +
                '}';
    }
}

使用 @Inject 需要加入依赖

<dependency>
            <groupId>javax.injectgroupId>
            <artifactId>javax.injectartifactId>
            <version>1version>
dependency>

@Inject 支持 @Primary 但是不支持(require = false)功能，因为没有属性值

3.4 方法|构造器位置的自动装配

@Controller
public class BookController {

    BookService bookService;

    public BookService getBookService() {
        return bookService;
    }

    //标注在方法上，Spring容器创建当前对象就会调用方法完成赋值
    //方法使用的参数，自定义类型的值从IOC容器中获取
    @Autowired
    public void setBookService(BookService bookService) {
        this.bookService = bookService;
    }

    @Override
    public String toString() {
        return "BookController{" +
                "bookService=" + bookService +
                '}';
    }
}

public class ScanTest {
    public static void main(String[] args) {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(ImportConfig.class);
        String[] beanDefinitionNames = applicationContext.getBeanNamesForType(Person.class);

        //获取当前操作系统的名字
        Environment environment = applicationContext.getEnvironment();
        String property = environment.getProperty("os.name");
        System.out.println(property);

        for (String s : beanDefinitionNames) {
            System.out.println(s);
        }
        Map<String, Person> beansOfType = applicationContext.getBeansOfType(Person.class);
        System.out.println(beansOfType);

    }
}

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
autoConfig
bookController
bookDao
bookService
bookDao2
------
BookController{bookService=auto.BookService@5bfa9431}
auto.BookService@5bfa9431

@Controller
public class BookController {
    // 默认加在Ioc容器中的组件，容器启动会调用无参构造器创建对象，再进行初始化赋值操作

    BookService bookService;

    @Autowired
    //如果只有这一个有参构造器，AutoWired可以省略
    public BookController (BookService bookService){
        this.bookService = bookService;
        System.out.println("有参构造器");
    }

    public BookService getBookService() {
        return bookService;
    }


    public void setBookService(BookService bookService) {
        this.bookService = bookService;
    }

    @Override
    public String toString() {
        return "BookController{" +
                "bookService=" + bookService +
                '}';
    }
}

有参构造器
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
autoConfig
bookController
bookDao
bookService
bookDao2
------
BookController{bookService=auto.BookService@358ee631}
auto.BookService@358ee631

Process finished with exit code 0

@Controller
public class BookController {
    // 默认加在Ioc容器中的组件，容器启动会调用无参构造器创建对象，再进行初始化赋值操作

    BookService bookService;

    
    public BookController (@Autowired BookService bookService){
        this.bookService = bookService;
        System.out.println("有参构造器");
    }

    public BookService getBookService() {
        return bookService;
    }

    @Autowired
    public void setBookService(@Autowired BookService bookService) {
        this.bookService = bookService;
    }

    @Override
    public String toString() {
        return "BookController{" +
                "bookService=" + bookService +
                '}';
    }
}

加到参数上是一样的下效果

@ComponentScan({"auto"})
@Configuration
public class AutoConfig {

	//@Autowired 也可不写
    @Bean
    public BookController bookController(@Autowired BookService bookService) {
        BookController bookController = new BookController(bookService);
        return bookController;

    }
}

3.5 Aware注入Spring底层组件&原理

  自定义组件要想使用Spring容器底层的一些组件(ApplicationContext,BeanFactory,xxx);自定义组件需要实现xxxAware接口。在创建对象的时候，会调用接口规定的方法注入相关组件，一个 bean实现了ApplicationContextAware接口，对应的有一个ApplicationContextAwareProcessor接口在init方法之前将容器注入到自定义组件中

@Component
public class Red implements ApplicationContextAware, BeanNameAware, EmbeddedValueResolverAware {

    private ApplicationContext applicationContext;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    //获取当前bean的name值
    @Override
    public void setBeanName(String name) {
        System.out.println("RedBean的名字" + name);
    }

    //解析spring的表达式解析器  ${}可以取出环境变量和配置文件中的值
    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        String s = resolver.resolveStringValue("#{1+2}" + "${os.name}");
        System.out.println(s);
    }

    @Override
    public String toString() {
        return "Red{" +
                "applicationContext=" + applicationContext +
                '}';
    }
}

RedBean的名字red
3Windows 10
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
autoConfig
red
------
Red{applicationContext=org.springframework.context.annotation.AnnotationConfigApplicationContext@2eafffde: startup date [Fri Sep 20 15:08:09 CST 2019]; root of context hierarchy}
org.springframework.context.annotation.AnnotationConfigApplicationContext@2eafffde: startup date [Fri Sep 20 15:08:09 CST 2019]; root of context hierarchy

Process finished with exit code 0

在此处打断点，查看方法的调用栈

3.6 @Profile环境搭建

  Spring为我们提供的可以根据当前环境，动态的激活和切换一系列组件的功能
这里以数据源为例：创建不同环境的数据源

        <dependency>
            <groupId>c3p0groupId>
            <artifactId>c3p0artifactId>
            <version>0.9.1.1version>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>5.1.5version>
        dependency>

dbconfig.properties

username=root
password=a123456
driverclass=com.mysql.jdbc.Driver

package profile;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.EmbeddedValueResolverAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;
import org.springframework.util.StringValueResolver;

import javax.sql.DataSource;
import java.beans.PropertyVetoException;

/**
 *Desc:
 *@author:chengli
 *@date:2019/9/20 15:39
 */
@Configuration
@PropertySource("classpath:/dbconfig.properties")
public class MianConfigOfProfile implements EmbeddedValueResolverAware {

    @Value("${username}")
    private String username;

    private StringValueResolver valueResolver;
    private String driverclass;

    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        this.valueResolver = resolver;
        driverclass = valueResolver.resolveStringValue("${driverclass}");
    }

    @Bean
    public DataSource dataSourceDev (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }

    @Bean
    public DataSource dataSourceSit (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }
    @Bean
    public DataSource dataSourcePro (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }
}

public class ProfileTest {

    @Test
    public void test1() {
        ApplicationContext applicationContext = new AnnotationConfigApplicationContext(MianConfigOfProfile.class);
        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        System.out.println("------");
        for (String s : beanDefinitionNames) {
            System.out.println(s);
        }
        System.out.println("------");
    }
}

------
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
mianConfigOfProfile
dataSourceDev
dataSourceSit
dataSourcePro
------

Process finished with exit code 0

3.7 @Profile根据环境注册

@Profile用来指定组件在哪个环境下才能被注册到容器中，不指定的话在任何情况下都能注册这个组件。
1、加了环境标识的bean,只有这个环境激活的情况下才能注册到容器中，默认是default

@Configuration
@PropertySource("classpath:/dbconfig.properties")
public class MianConfigOfProfile implements EmbeddedValueResolverAware {

    @Value("${username}")
    private String username;

    private StringValueResolver valueResolver;
    private String driverclass;

    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        this.valueResolver = resolver;
        driverclass = valueResolver.resolveStringValue("${driverclass}");
    }

    @Profile("default")
    @Bean
    public DataSource dataSourceDev (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }
    @Profile("sit")
    @Bean
    public DataSource dataSourceSit (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }

    @Profile("pro")
    @Bean
    public DataSource dataSourcePro (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;

    }
}

------
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
mianConfigOfProfile
dataSourceDev
------

Process finished with exit code 0

2、通过运行参数指定激活哪个环境

@Configuration
@PropertySource("classpath:/dbconfig.properties")
public class MianConfigOfProfile implements EmbeddedValueResolverAware {

    @Value("${username}")
    private String username;

    private StringValueResolver valueResolver;
    private String driverclass;

    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        this.valueResolver = resolver;
        driverclass = valueResolver.resolveStringValue("${driverclass}");
    }
    @Profile("dev")
    @Bean
    public Person person () {
        return new Person();
    }


    @Profile("dev")
    @Bean
    public DataSource dataSourceDev (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }
    @Profile("sit")
    @Bean
    public DataSource dataSourceSit (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }

    @Profile("pro")
    @Bean
    public DataSource dataSourcePro (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;

    }
}

------
org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
mianConfigOfProfile
person
dataSourceDev
------

Process finished with exit code 0

2、通过无参构造获取容器

public class ProfileTest {

    @Test
    public void test1() {
        //1、设置一个applicationContext
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
        //2、设置需要激活的环境
        applicationContext.getEnvironment().setActiveProfiles("dev","sit");
        //3、注册配置类
        applicationContext.register(MianConfigOfProfile.class);
        //4、启动刷新
        applicationContext.refresh();

        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        Arrays.asList(beanDefinitionNames).stream().forEach(s -> System.out.println(s));

    }
}

org.springframework.context.annotation.internalConfigurationAnnotationProcessor
org.springframework.context.annotation.internalAutowiredAnnotationProcessor
org.springframework.context.annotation.internalRequiredAnnotationProcessor
org.springframework.context.annotation.internalCommonAnnotationProcessor
org.springframework.context.event.internalEventListenerProcessor
org.springframework.context.event.internalEventListenerFactory
mianConfigOfProfile
person
dataSourceDev
dataSourceSit

Process finished with exit code 0

3、@Profile写在类上：表示只有是指定环境整个配置类上的bean才能生效

@Profile("pro")
@Configuration
@PropertySource("classpath:/dbconfig.properties")
public class MianConfigOfProfile implements EmbeddedValueResolverAware {

    @Value("${username}")
    private String username;

    private StringValueResolver valueResolver;
    private String driverclass;

    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        this.valueResolver = resolver;
        driverclass = valueResolver.resolveStringValue("${driverclass}");
    }
    @Profile("dev")
    @Bean
    public Person person () {
        return new Person();
    }


    @Profile("dev")
    @Bean
    public DataSource dataSourceDev (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }
    @Profile("sit")
    @Bean
    public DataSource dataSourceSit (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;
    }

    @Profile("pro")
    @Bean
    public DataSource dataSourcePro (@Value("${password}")String password) throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setJdbcUrl("jdbc:msyql:localhost:3306/test");
        dataSource.setDriverClass(driverclass);
        return dataSource;

    }
}

public class ProfileTest {

    @Test
    public void test1() {
        //1、设置一个applicationContext
        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
        //2、设置需要激活的环境
        applicationContext.getEnvironment().setActiveProfiles("dev");
        //3、注册配置类
        applicationContext.register(MianConfigOfProfile.class);
        //4、启动刷新
        applicationContext.refresh();

        String[] beanDefinitionNames = applicationContext.getBeanDefinitionNames();
        Arrays.asList(beanDefinitionNames).stream().forEach(s -> System.out.println(s));

    }
}

虽然底下的bean指定了配置环境，但是由于整个配置类都没有激活，所以加载不出来任何的ben
4、没有指定配置环境的bean在任何环境都会被加载

3.8 IOC小结

  1、@Conditional和 @Import 这两个注解在Spring底层使用的非常的频繁。
  2、更多的功能应该多翻阅Spring的官方文档
  3、只有给组件注入Spring的底层组件，才能实现Aop、声明式事务等等