装配Bean:JavaConfig@Bean@Configuration

使用JavaConfig方式进行Spring容器Bean装载

@Configuration

@Bean

@Autowired()

@Qualifier

@RunWith(SpringJUnit4ClassRunner.class)

@ContextConfiguration(classes={SpringJavaConfig.class})

我们模拟了两个bean，使用JavaConfig形式来加载beans,并使用单元测试方式，测试效果。

@Configuration –>指明该类为JavaConfig类

@Bean–>在方法上，表示方法最终要返回一个对象，这个对象将会出现在IOC容器中【默认的，bean的ID为方法名】。所以注意ID的唯一性，且使用@Bean在IOC中生成的bean为单例的。对于同一类型的Bean多次使用@Bean最终产生的还是同一个bean.

如

public MobilePhone iphone(){

return new IphoneMobilePhoneImpl()

}

public MobilePhone anotherIphone(){

return new IphoneMobilePhoneImpl()

}

最终实际为同一iphone

接口类，模拟业务方法

package com.xbz.learn.spring.autowire;

public interface MobilePhone {
/**
* 给XXX打电话
* @param phoneNumber
*/
public void callPerson(String phoneNumber);
}

实现类

package com.xbz.learn.spring.autowire;

/**
* MobilePhone接口的iphone实现类
* @author xbz
*
*/
public class IphoneMobilePhoneImpl implements MobilePhone{

public void callPerson(String phoneNumber) {
System.out.println("iphone 正在向【"+phoneNumber+"】打电话");
}

}

package com.xbz.learn.spring.autowire;

public class XiaoMiPhone implements MobilePhone {

public void callPerson(String phoneNumber) {
System.out.println("小米手机 正在向【"+phoneNumber+"】打电话");
}

}

JavaConfig类

package com.xbz.learn.spring.autowire.javaConfig;

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

import com.xbz.learn.spring.autowire.IphoneMobilePhoneImpl;
import com.xbz.learn.spring.autowire.MobilePhone;
import com.xbz.learn.spring.autowire.XiaoMiPhone;

@Configuration
public class SpringJavaConfig {

@Bean(name="iphone")
public MobilePhone setIphone(){
return new IphoneMobilePhoneImpl();
}

@Bean(name="xiaomi")
public MobilePhone setXiaomiPhone(){
return new XiaoMiPhone();
}

}

测试类

package com.xbz.learn.spring.autowire.javaConfig;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import com.xbz.learn.spring.autowire.MobilePhone;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes={SpringJavaConfig.class})
public class SpringJavaConfigTest {

@Autowired()@Qualifier("iphone")
private MobilePhone iphone;

@Autowired()@Qualifier("xiaomi")
private MobilePhone xiaomi;

@Test
public void testJavaConfig(){
System.out.println("iphone:"+iphone);
System.out.println("xiaomi:"+xiaomi);
System.out.println("is same?"+(iphone==xiaomi));
4000

}
}