spring bean的初始化方式（init,destroy）

快来打我* 2021-10-29 08:44 324阅读 0赞

spring容器中bean的初始化方式大体有三种：

@PostConstruct ，@PreDestroy：  从Java EE5规范开始，Servlet中增加了两个影响Servlet生命周期的注解，@PostConstruct和@PreDestroy。@PostConstruct会在Servlet构造函数之后，初始化之前执行

package com.edu.bean;
    
    
    import org.springframework.stereotype.Component;
    
    import javax.annotation.PostConstruct;
    import javax.annotation.PreDestroy;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    @Component
    public class Color {
    
        @PostConstruct
        public void init(){
            System.out.println("init......");
    
        }
    
        @PreDestroy
        public void destroy(){
            System.out.println("destroy.........");
    
        }
    
    
    }
    
    package com.edu.bean;
    
    import org.springframework.context.annotation.AnnotationConfigApplicationContext;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    public class Test1 {
        public static void main(String[] args) {
    
            AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext("com.edu.bean");
            context.close();
    
        }
    }

输出：

init......

destroy.........

*  @Bean中指定initMethod，destroyMethod方法

package com.edu.bean;
    
    
    import javax.annotation.PostConstruct;
    import javax.annotation.PreDestroy;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    
    public class Color {
    
        @PostConstruct
        public void init(){
            System.out.println("init......");
    
        }
    
        public void init1(){
            System.out.println("init1......");
    
        }
    
        @PreDestroy
        public void destroy(){
            System.out.println("destroy.........");
    
        }
    
        public void destroy1(){
            System.out.println("destroy1.........");
    
        }
    
    
    }
    
    
    package com.edu.bean;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    @Configuration
    class Config {
    
        @Bean(name = "color",initMethod = "init1",destroyMethod = "destroy1")
        public  Color getColor(){
    
            return new Color();
        }
    
    }
    
    
    package com.edu.bean;
    
    import org.springframework.context.annotation.AnnotationConfigApplicationContext;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    public class Test1 {
        public static void main(String[] args) {
    
            AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(Config.class);
            context.close();
    
        }
    }

输出：

init......  
init1......

destroy.........  
destroy1.........

证明@PostConstruct 修饰的方法是在initMethod标注的方法之前执行，@PreDestroy修饰的方法是在destroyMethod 标注的方法之前执行

*  interface InitializingBean，DisposableBean：重写afterPropertiesSet，destroy方法

package com.edu.bean;
    
    
    import org.springframework.beans.factory.DisposableBean;
    import org.springframework.beans.factory.InitializingBean;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.PostConstruct;
    import javax.annotation.PreDestroy;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    @Component
    public class Color implements InitializingBean, DisposableBean {
    
        @PostConstruct
        public void init(){
            System.out.println("init......");
    
        }
        @PreDestroy
        public void destroy(){
            System.out.println("destroy.........");
    
        }
        @Override
        public void afterPropertiesSet() throws Exception {
            System.out.println("init1.........");
        }
    
        @Override
        public void destroy() throws Exception {
            System.out.println("destroy1......");
        }
    }
    
    
    package com.edu.bean;
    
    import org.springframework.context.annotation.AnnotationConfigApplicationContext;
    
    /**
     * Created by IntelliJ IDEA.
     * User: chenzhubing
     * Date: 2019/6/17
     */
    public class Test1 {
        public static void main(String[] args) {
    
            AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext("com.edu.bean");
            context.close();
    
        }
    }

输出：

init......  
init1.........

destroy.........  
destroy1......

转载于:https://www.cnblogs.com/chenzhubing/p/11041360.html