Spring学习五----------Bean的配置之Bean的生命周期

© 版权声明：本文为博主原创文章，转载请注明出处

Bean的生命周期

1.定义

2.初始化

3.使用

4.销毁

初始化和销毁的三种方式

1.实现org.springframework.beans.factory.InitializingBean和org.springframework.beans.factory.DisposableBean接口

2.配置init-method和destroy-method

3.配置全局默认初始化和销毁方法default-init-method和default-destroy-method

实例

1.项目结构

2.pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>org.spring</groupId>
	<artifactId>Spring</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>Spring</name>
	<url>http://maven.apache.org</url>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<spring.version>4.3.7.RELEASE</spring.version>
	</properties>

	<dependencies>
		<!-- junit依赖 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<!-- spring依赖 -->
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-core</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-beans</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-context</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-web</artifactId>
		    <version>${spring.version}</version>
		</dependency>
		<dependency>
		    <groupId>org.springframework</groupId>
		    <artifactId>spring-webmvc</artifactId>
		    <version>${spring.version}</version>
		</dependency>

	</dependencies>
</project>

3.spring-beanlifecycle.xml（三选一）

　　3.1 实现org.springframework.beans.factory.InitializingBean和org.springframework.beans.factory.DisposableBean接口

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

	<bean id="beanLifeCycle" class="org.spring.bean.BeanLifeCycle"/>        

</beans>

　　3.2 配置init-method和destroy-method

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

	<bean id="beanLifeCycle" class="org.spring.bean.BeanLifeCycle"
		init-method="start" destroy-method="stop"/>        

</beans>

　　3.3 配置全局默认初始化和销毁方法default-init-method和default-destroy-method

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd"
        default-init-method="defaultInit" default-destroy-method="defaultDestroy">

	<bean id="beanLifeCycle" class="org.spring.bean.BeanLifeCycle"/>        

</beans>

4.BeanLifeCycle.java（三选一）

　　4.1 实现org.springframework.beans.factory.InitializingBean和org.springframework.beans.factory.DisposableBean接口

package org.spring.bean;

import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;

public class BeanLifeCycle implements InitializingBean, DisposableBean {

	/**
	 * 初始化
	 */
	public void afterPropertiesSet() throws Exception {

		System.out.println("Bean Init.");

	}

	/**
	 * 销毁
	 */
	public void destroy() throws Exception {

		System.out.println("Bean Destroy.");

	}

}

　　4.2 配置init-method和destroy-method

package org.spring.bean;

public class BeanLifeCycle {

	/**
	 * 初始化
	 */
	public void start() throws Exception {

		System.out.println("Bean Start.");

	}

	/**
	 * 销毁
	 */
	public void stop() throws Exception {

		System.out.println("Bean Stop.");

	}

}

　　4.3 配置全局默认初始化和销毁方法default-init-method和default-destroy-method

package org.spring.bean;

public class BeanLifeCycle {

	/**
	 * 初始化
	 */
	public void defaultInit() throws Exception {

		System.out.println("Bean DefaultInit.");

	}

	/**
	 * 销毁
	 */
	public void defaultDestroy() throws Exception {

		System.out.println("Bean DefaultDestroy.");

	}

}

5.UnitTestBase

package org.spring.ioc.test;

import org.junit.After;
import org.junit.Before;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.util.StringUtils;

/**
 * 单元测试初始化类
 *
 */
public class UnitTestBase {

	private ClassPathXmlApplicationContext context;
	private String springXmlPath;

	/**
	 * 无参构造器
	 */
	public UnitTestBase() {

	}

	/**
	 * 含参构造器
	 *
	 * @param springXmlPath
	 * 						spring配置文件路径
	 */
	public UnitTestBase(String springXmlPath) {

		this.springXmlPath = springXmlPath;

	}

	/**
	 * 初始化spring配置文件
	 */
	@Before//在@Test注解的方法执行前执行
	public void before() {

		if(StringUtils.isEmpty(springXmlPath)) {//默认spring配置文件路径
			springXmlPath = "classpath*:spring-*.xml";
		}
		//加载配置文件，一个context表示一个容器
		context = new ClassPathXmlApplicationContext(springXmlPath.split("[,\\s]+"));
		//启动组件
		context.start();

	}

	/**
	 * 销毁spring组件
	 */
	@After//在@Test注解的方法执行后执行
	public void after() {

		context.destroy();//销毁组件

	}

	/**
	 * 获取spring中定义的bean实例
	 *
	 * @param beanId
	 *
	 * @return
	 */
	@SuppressWarnings("unchecked")
	protected <T extends Object> T getBean(String beanId) {

		return (T) context.getBean(beanId);

	}

	/**
	 * 获取spring中定义的bean实例
	 *
	 * @param clazz
	 *
	 * @return
	 */
	protected <T extends Object> T getBean(Class<T> clazz) {

		return (T) context.getBean(clazz);

	}

}

6.TestBeanLifeCycle

package org.spring.ioc.test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;
import org.spring.bean.BeanLifeCycle;

@RunWith(BlockJUnit4ClassRunner.class)//指定JUnit默认执行类
public class TestBeanLifeCycle extends UnitTestBase {

	public TestBeanLifeCycle() {//通过构造方法传入spring配置文件路径

		super("classpath*:spring-beanlifecycle.xml");

	}

	@Test
	public void testScope() {

		BeanLifeCycle bean = super.getBean("beanLifeCycle");

	}

}

7.效果预览

　　7.1 实现org.springframework.beans.factory.InitializingBean和org.springframework.beans.factory.DisposableBean接口

　　7.2 配置init-method和destroy-method

　　7.3 配置全局默认初始化和销毁方法default-init-method和default-destroy-method

　　7.4 三种方式一起执行

8.总结

　　1）实现接口方式的初始化和销毁 先于 配置init-method和destroy-method

　　2）当 实现接口方式的初始化和销毁或配置init-method和destroy-method 时，配置全局默认初始化和销毁方法default-init-method和default-destroy-method不生效

参考：http://www.imooc.com/video/3751