Spring学习--5 Bean生命周期管理

Bean生命周期管理

目的：掌握Bean生命周期管理方法，主要是标明initMethod和destroyMethod方法。
两种形式可用来管理Bean的初始化和销毁，一种是在配置中采用@Bean注解，@Bean(initMethod=”INIT_METHOD”, destroyMethod=”DESTROY_METHOD”)；另外一种是在Bean的方法上分别注解@PostConstruct和@PreDestroy，用来标明initMethod和destroyMethod方法。

1、@Bean形式的Bean

package com.prepost;

import org.springframework.context.annotation.Bean;

/**@Bean形式的Bean
 * @author apple
 *
 */
public class BeanWayService {
    public void init() {
        System.out.println("@Bean-init-method");
    }

    public void destroy() {
        System.out.println("@Bean-destory-method");
    }

    public BeanWayService() {
        super();
        System.out.println("初始化构造函数-BeanWayService");
    }
}

2、JSR250形式的Bean

package com.prepost;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

/**JSR250形式的Bean
 * @author apple
 *
 */
public class JSR250WayService {
    @PostConstruct
    public void init() {
        System.out.println("JSR250-init-method");
    }

    @PreDestroy
    public void destroy() {
        System.out.println("JSR250-destroy-method");
    }

    public JSR250WayService() {
        super();
        System.out.println("初始化构造函数-JSR250WayService");
    }

}

3、Configuration配置类

package com.prepost;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan("com.prepost")
public class PrePostConfig {
    //@Bean形式声明初始化方法和销毁方法
    @Bean(initMethod="init", destroyMethod="destroy")   public BeanWayService beanWayService() {
        return new BeanWayService();
    }

    @Bean
    public JSR250WayService jsr250WayService() {
        return new JSR250WayService();
    }

}

4、测试

package com.prepost;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Bootrap {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext(PrePostConfig.class);

        context.getBean(BeanWayService.class);
        context.getBean(JSR250WayService.class);

        context.close();
    }
}