有以下三种配置
在xml中配置
在java中配置
bean自动装配
自动装配
这里以转载CD为例子
首先需要建立CD概念
即,定义一个cd接口
只需要实现添加两个注解,
package com.ming;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
/**
* 定义cd接口
* @author ming
*/
@Configuration
@ComponentScan
public interface CompactDisc {
/**
* 规定方法为play
*/
void play();
}
package com.ming;
import org.springframework.stereotype.Component;
/**
*
* @author ming
*/
// 启用组件扫描
@Component
class SgtPeppers implements CompactDisc {
private String title = "标题";
private String artist = "内容";
/**
* 规定方法为play
*/
@Override
public void play() {
System.out.println(this.artist + this.title);
}
}
package com.ming;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import static org.junit.Assert.*;
public class CompactDiscTest {
private ApplicationContext applicationContext = null;
@Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@After
public void tearDown() throws Exception {
}
@Test
public void play() {
CompactDisc compactDisc = applicationContext.getBean(CompactDisc.class);
assertNotNull(compactDisc);
}
}
扫描的时候,会直接按照该类所在的包,作为基础包,进行扫描
对依赖的实现自动装配
添加注解以后,初始化bean以后,会尽可能的满足bean的依赖
目录如下
package com.ming;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
*
* @author ming
*/
@Component
public class CDPlay implements MediaPlayer {
CompactDisc compactDisc = null;
@Autowired
public CDPlay(CompactDisc compactDisc){
this.compactDisc = compactDisc;
}
/**
* 规定方法为play
*/
@Override
public void play() {
compactDisc.play();
}
}
package com.ming;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
/**
* 定义cd接口
* @author ming
*/
@Configuration
@ComponentScan
public interface CompactDisc {
/**
* 规定方法为play
*/
void play();
}
package com.ming;
import org.springframework.context.annotation.ComponentScan;
/**
* @author ming
*/
@ComponentScan
public interface MediaPlayer {
/**
* 规定方法为play
*/
public void play();
}
package com.ming;
import org.springframework.stereotype.Component;
/**
*
* @author ming
*/
// 启用组件扫描
@Component
class SgtPeppers implements CompactDisc {
private String title = "标题";
private String artist = "内容";
/**
* 规定方法为play
*/
@Override
public void play() {
System.out.println(this.artist + this.title);
}
}
<?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="com.ming"/>
</beans>
package com.ming;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import static org.junit.Assert.*;
public class CompactDiscTest {
private ApplicationContext applicationContext = null;
@Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
}
@After
public void tearDown() throws Exception {
}
@Test
public void play() {
MediaPlayer mediaPlayer = (MediaPlayer) applicationContext.getBean(MediaPlayer.class);
mediaPlayer.play();
assertNotNull(mediaPlayer);
}
}
运行结果
在这里,在装配的时候,尽量满足配置规则进行装配
Java代码装配bean
package com.ming;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
*
* @author ming
*/
@Configuration // 注解表明这是一个配置类
public class CDPlayerConfig {
@Bean
public CompactDisc sgtPeppers(){
// 此处进行装配
return new SgtPeppers();
}
/**
* 注入装配
* @return
*/
@Bean
public CDPlay cdPlay(){
return new CDPlay(this.sgtPeppers());
}
}
点击查看更多内容
为 TA 点赞
评论
共同学习,写下你的评论
评论加载中...
作者其他优质文章
正在加载中
感谢您的支持,我会继续努力的~
扫码打赏,你说多少就多少
赞赏金额会直接到老师账户
支付方式
打开微信扫一扫,即可进行扫码打赏哦