Spring @Qualifier Example

@Qualifier often appear in an interface, a number of implementation class calls in the case, in some choice processing, give the use of examples, realize this kind of beauty.

package spring;import org.springframework.beans.factory.annotation.autowired;import  org.springframework.beans.factory.annotation.qualifier;import  org.springframework.context.annotation.annotationconfigapplicationcontext;import  org.springframework.context.annotation.componentscan;import  org.springframework.context.annotation.configuration;import org.springframework.stereotype.component; import javax.annotation.postconstruct;import java.lang.annotation.elementtype;import  java.lang.annotation.retention;import java.lang.annotation.retentionpolicy;import  Java.lang.annotation.target;import static spring. Spring.platform, @Configuration @componentscanpublic class spring {    public  static void main (String[] args)  {        new  annotationconfigapplicationcontext (spring.class);     }    @autowired     @Platform (Platform.OperatingSystems.ANDROID)     private  MarketPlace android;     @Autowired      @Platform ( Platform.OperatingSystems.IOS)     private MarketPlace ios;      @PostConstruct     public void qualifythetweets ()  {         system.out.println ("ios:"  + this.ios);         system.out.println ("android:"  + this.android);    }     // the type has to be public!     @Target ({ Elementtype.field,            elementtype.method,             ElementType.TYPE,          &nbsP;  elementtype.parameter})      @Retention (retentionpolicy.runtime)       @Qualifier     public static  @interface  Platform {         operatingsystems value ();         public static enum OperatingSystems {             IOS,             android        }    }}

Interface:

Interface MarketPlace {}

Implementing Class One:

@Component @platform (Platform.OperatingSystems.IOS) class Applemarketplace implements MarketPlace {@Override public S    Tring toString () {return ' Apple '; }}

Implementing Class Two:

@Component @platform (Platform.OperatingSystems.ANDROID) class Googlemarketplace implements MarketPlace {@Override pub    Lic String toString () {return ' Android '; }}

Spring @Qualifier Example