@Configuration

 

1、通过配置文件注入类

@Configuration

@PropertySource("classpath:config/redis.properties")

2、注册bean

1)@Configuration+@Bean方式注册

public class TestBean {

    private String username;
    private String url;
    private String password;

    public void sayHello() {
        System.out.println("TestBean sayHello...");
    }

    public String toString() {
        return "username:" + this.username + ",url:" + this.url + ",password:" + this.password;
    }

    public void start() {
        System.out.println("TestBean 初始化。。。");
    }

    public void cleanUp() {
        System.out.println("TestBean 销毁。。。");
    }
}

@Configuration
public class TestConfiguration {
    public TestConfiguration() {
        System.out.println("TestConfiguration容器启动初始化。。。");
    }

    // @Bean注解注册bean,同时可以指定初始化和销毁方法
    // @Bean(name="testBean",initMethod="start",destroyMethod="cleanUp")
    @Bean
    @Scope("prototype")
    public TestBean testBean() {
        return new TestBean();
    }
}

public class TestMain {
    public static void main(String[] args) {

        // @Configuration注解的spring容器加载方式,用AnnotationConfigApplicationContext替换ClassPathXmlApplicationContext
        ApplicationContext context = new AnnotationConfigApplicationContext(TestConfiguration.class);
         //获取bean
        TestBean tb = (TestBean) context.getBean("testBean");
        tb.sayHello();
    }
}

2)@Configuration启动容器+@ComponentScan+@Component注册Bean
//添加注册bean的注解
@Component
public class TestBean {

    private String username;
    private String url;
    private String password;

    public void sayHello() {
        System.out.println("TestBean sayHello...");
    }

    public String toString() {
        return "username:" + this.username + ",url:" + this.url + ",password:" + this.password;
    }

    public void start() {
        System.out.println("TestBean 初始化。。。");
    }

    public void cleanUp() {
        System.out.println("TestBean 销毁。。。");
    }
}

@Configuration
//添加自动扫描注解,basePackages为TestBean包路径
@ComponentScan(basePackages = "com.dxz.demo.configuration")
public class TestConfiguration {
    public TestConfiguration() {
        System.out.println("TestConfiguration容器启动初始化。。。");
    }

    /*// @Bean注解注册bean,同时可以指定初始化和销毁方法
    // @Bean(name="testNean",initMethod="start",destroyMethod="cleanUp")
    @Bean
    @Scope("prototype")
    public TestBean testBean() {
        return new TestBean();
    }*/
}

public class TestMain {
    public static void main(String[] args) {

        // @Configuration注解的spring容器加载方式,用AnnotationConfigApplicationContext替换ClassPathXmlApplicationContext
        ApplicationContext context = new AnnotationConfigApplicationContext(TestConfiguration.class);
         //获取bean
        TestBean tb = (TestBean) context.getBean("testBean");
        tb.sayHello();
    }
}

备注1:可以使用基于 Java 的配置来管理 bean 的生命周期。@Bean 支持两种属性,即 initMethod 和destroyMethod,这些属性可用于定义生命周期方法。在实例化 bean 或即将销毁它时,容器便可调用生命周期方法。生命周期方法也称为回调方法,因为它将由容器调用。使用 @Bean 注释注册的 bean 也支持 JSR-250 规定的标准 @PostConstruct 和 @PreDestroy 注释。如果您正在使用 XML 方法来定义 bean,那么就应该使用 bean 元素来定义生命周期回调方法。

 

备注2:可以用两种方式获取注解上下文

1)ApplicationContext context = new AnnotationConfigApplicationContext(TestConfiguration.class);

2)ApplicationContext ctx = new AnnotationConfigApplicationContext();

  ctx.register(AppContext.class)

 

备注3:@Configuration+@Bean注册类时,如果有多个,则可以调用,相当于在application.xml中一个bean定义时引用另一个bean(注册bean的先后顺序)

 

备注4:如果是在controller这类受容器管理的类中调用,则直接如下定义即可使用

@Autowired

TestBean testBean;