Spring Bean的初始化和销毁实例详解

<dependency>
  <groupId>javax.annotation</groupId>
  <artifactId>jsr250-api</artifactId>
  <version>1.0</version>
</dependency>

package com.wisely.highlight_spring4.ch2.prepost;
public class BeanWayService {
   public void init(){
      System.out.println("@Bean-init-method");
    }
    public BeanWayService() {
      super();
      System.out.println("初始化构造函数-BeanWayService");
    }
    public void destroy(){
      System.out.println("@Bean-destory-method");
    }
}

package com.wisely.highlight_spring4.ch2.prepost;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
public class JSR250WayService {
  @PostConstruct //在构造函数执行之后执行
  public void init(){
    System.out.println("jsr250-init-method");
  }
  public JSR250WayService() {
    super();
    System.out.println("初始化构造函数-JSR250WayService");
  }
  @PreDestroy //在Bean销毁之前执行
  public void destroy(){
    System.out.println("jsr250-destory-method");
  }
}

package com.wisely.highlight_spring4.ch2.prepost;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
@Configuration
@ComponentScan("com.wisely.highlight_spring4.ch2.prepost")
public class PrePostConfig {
  //initMethod和destroyMethod指定BeanWayService类的
  //init和destroy方法在构造函数之后、Bean销毁之前执行
  @Bean(initMethod="init",destroyMethod="destroy")
  BeanWayService beanWayService(){
    return new BeanWayService();
  }
  @Bean
  JSR250WayService jsr250WayService(){
    return new JSR250WayService();
  }
}

package com.wisely.highlight_spring4.ch2.prepost;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Main {
  public static void main(String[] args) {
    AnnotationConfigApplicationContext context =
        new AnnotationConfigApplicationContext(PrePostConfig.class);
    BeanWayService beanWayService = context.getBean(BeanWayService.class);
    JSR250WayService jsr250WayService = context.getBean(JSR250WayService.class);
    context.close();
  }
}