Spring学习十一----------Bean的配置之基于Java的容器注解@Bean

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@Bean

-@Bean标识一个用于配置和初始化一个由SpringIOC容器管理的新对象的方法，类似于XML配置文件的<bean/>

-可以在Spring的@Component注解的类中使用@Bean注解任何方法（仅仅是可以）

-在上一点中，通过使用的是@Configuration

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/maven-v4_0_0.xsd">

	<modelVersion>4.0.0</modelVersion>

	<groupId>org.springbean</groupId>
	<artifactId>Spring-JavaBean</artifactId>
	<packaging>war</packaging>
	<version>0.0.1-SNAPSHOT</version>
	<name>Spring-JavaBean Maven Webapp</name>
	<url>http://maven.apache.org</url>

	<properties>
		<spring.version>4.3.8.RELEASE</spring.version>
	</properties>

	<dependencies>
		<!-- junit依赖 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<!-- spring核心依赖 -->
		<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>
	</dependencies>

	<build>
		<finalName>Spring-JavaBean</finalName>
	</build>

</project>

3.spring-javabean.xml

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

	<context:component-scan base-package="org.spring.javabean"/>

</beans>

4.Store.java

package org.spring.javabean;

public interface Store {

}

5.StringStore.java

package org.spring.javabean;

public class StringStore implements Store {

	public void init() {

		System.out.println("执行了init方法");

	}

	public void destroy() {

		System.out.println("执行了destroy方法");

	}

}

6.StoreConfig.java

package org.spring.javabean;

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

@Configuration
public class StoreConfig {

	@Bean(name="stringStore", initMethod="init", destroyMethod="destroy")
	public Store stringStore() {

		return new StringStore();

	}

}

7.TestBase.java

package org.spring.javabean.test;

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

public class TestBase {

	private ClassPathXmlApplicationContext context;
	private String springXmlPath;

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

	}

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

		this.springXmlPath = springXmlPath;

	}

	/**
	 * 初始化加载spring配置文件到IOC容器中
	 */
	@Before
	public void before() {

		if(StringUtils.isEmpty(springXmlPath)){
			springXmlPath = "classpath:spring-*.xml";
		}
		context = new ClassPathXmlApplicationContext(springXmlPath.split("[,\\s]+"));
		context.start();

	}

	/**
	 * 销毁IOC容器
	 */
	@After
	public void after() {

		if(context != null){
			context.destroy();
		}

	}

	/**
	 * 通过bean ID获取bean对象
	 *
	 * @param beanId
	 * 				bean ID
	 * @return
	 */
	public Object getBean(String beanId) {

		return context.getBean(beanId);

	}

}

8.TestSpringJavaBean.java

package org.spring.javabean.test;

import org.junit.Test;
import org.spring.javabean.Store;

public class TestSpringJavaBean extends TestBase {

	public TestSpringJavaBean() {

		super("classpath:spring-javabean.xml");

	}

	@Test
	public void testJavaBean() {

		Store store = (Store) super.getBean("stringStore");
		System.out.println(store.getClass().getName());

	}

}

9.效果预览

参考：http://www.imooc.com/video/4033