SPRING IN ACTION 第4版笔记-第二章WIRING BEANS-008-在Java配置文件中引入xml配置文件@Import、@ImportResource

1.

package soundsystem;
import org.springframework.beans.factory.annotation.Autowired;

public class CDPlayer implements MediaPlayer {
  private CompactDisc cd;

  @Autowired
  public CDPlayer(CompactDisc cd) {
    this.cd = cd;
  }

  public void play() {
    cd.play();
  }

}

2.

public class SgtPeppers implements CompactDisc {

  private String title = "Sgt. Pepper's Lonely Hearts Club Band";  
  private String artist = "The Beatles";
  
  public void play() {
    System.out.println("Playing " + title + " by " + artist);
  }

}

3.

package soundsystem;

import java.util.List;

public class BlankDisc implements CompactDisc {

  private String title;
  private String artist;
  private List<String> tracks;

  public BlankDisc(String title, String artist, List<String> tracks) {
    this.title = title;
    this.artist = artist;
    this.tracks = tracks;
  }

  public void play() {
    System.out.println("Playing " + title + " by " + artist);
    for (String track : tracks) {
      System.out.println("-Track: " + track);
    }
  }

}

一、在Java配置文件中引入Java配置文件

1.

package soundsystem;

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

@Configuration
public class CDConfig {
  @Bean
  public CompactDisc compactDisc() {
    return new SgtPeppers();
  }
}

2.则在CDPlayerConfig中可直接用@import引入上面的配置或新建一个文件引入这两个配置文件

(1)

@Configuration
@Import(CDConfig.class)
public class CDPlayerConfig {
@Bean
public CDPlayer cdPlayer(CompactDisc compactDisc) {
return new CDPlayer(compactDisc);
}
}

(2)

package soundsystem;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
@Configuration
@Import({CDPlayerConfig.class, CDConfig.class})
public class SoundSystemConfig {
}

二、在Java配置文件中引入xml配置文件，可用@ImportResource

1.cd-config.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:c="http://www.springframework.org/schema/c"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

  <bean id="compactDisc"
        class="soundsystem.BlankDisc"
        c:_0="Sgt. Pepper's Lonely Hearts Club Band"
        c:_1="The Beatles">
    <constructor-arg>
      <list>
        <value>Sgt. Pepper's Lonely Hearts Club Band</value>
        <value>With a Little Help from My Friends</value>
        <value>Lucy in the Sky with Diamonds</value>
        <value>Getting Better</value>
        <value>Fixing a Hole</value>
        <!-- ...other tracks omitted for brevity... -->
      </list>
    </constructor-arg>
  </bean>

</beans>

2.SoundSystemConfig.java

package soundsystem;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.ImportResource;

@Configuration
@Import(CDPlayerConfig.class)
@ImportResource("classpath:cd-config.xml")
public class SoundSystemConfig {

}

Both beans— CDPlayer configured in JavaConfig and BlankDisc configured in XML —
will be loaded into the Spring container. And because CDPlayer ’s @Bean method
accepts a CompactDisc as a parameter, the BlankDisc bean will be wired into it, even
though it’s configured in XML .