摘要：有以下三種配置在中配置在中配置自動裝配自動裝配這里以轉載為例子首先需要建立概念即，定義一個接口只需要實現添加兩個注解，定義接口規定方法為啟用組件掃描標題內容規定方法為掃描的時候，會直接按照該類所在的包，作為基礎包，進行掃描對依賴的實現自動裝

有以下三種配置
在xml中配置
在java中配置
bean自動裝配

這里以轉載CD為例子

首先需要建立CD概念

即，定義一個cd接口

只需要實現添加兩個注解，

package com.ming;

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

/**
 * 定義cd接口
 * @author ming
 */
@Configuration
@ComponentScan
public interface CompactDisc {
    /**
     * 規定方法為play
     */
    void play();
}

package com.ming;

import org.springframework.stereotype.Component;

/**
 *
 * @author ming
 */

// 啟用組件掃描
@Component
class SgtPeppers implements CompactDisc {
    private String title = "標題";
    private String artist = "內容";
    /**
     * 規定方法為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);
    }
}

掃描的時候，會直接按照該類所在的包，作為基礎包，進行掃描

添加注解以后，初始化bean以后，會盡可能的滿足bean的依賴

目錄如下

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;
    }

    /**
     * 規定方法為play
     */
    @Override
    public void play() {
        compactDisc.play();
    }
}

package com.ming;

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

/**
 * 定義cd接口
 * @author ming
 */
@Configuration
@ComponentScan
public interface CompactDisc {
    /**
     * 規定方法為play
     */
    void play();
}

package com.ming;

import org.springframework.context.annotation.ComponentScan;

/**
 * @author ming
 */
@ComponentScan
public interface MediaPlayer {
    /**
     * 規定方法為play
     */
    public void play();
}

package com.ming;

import org.springframework.stereotype.Component;

/**
 *
 * @author ming
 */

// 啟用組件掃描
@Component
class SgtPeppers implements CompactDisc {
    private String title = "標題";
    private String artist = "內容";
    /**
     * 規定方法為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.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);
    }
}

運行結果

在這里，在裝配的時候，盡量滿足配置規則進行裝配

package com.ming;

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

/**
 *
 * @author ming
 */
@Configuration  // 注解表明這是一個配置類
public class CDPlayerConfig {

    @Bean
    public CompactDisc sgtPeppers(){
        // 此處進行裝配
        return new SgtPeppers();
    }

    /**
     * 注入裝配
     * @return
     */
    @Bean
    public CDPlay cdPlay(){
        return new CDPlay(this.sgtPeppers());
    }
}