Guice 注解@Provides

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package com.ilucky.guice.test10;import com.google.inject.Guice;import com.google.inject.Injector;import com.google.inject.Key;/** * v1.0:20161114 * @author IluckySi *  * 注解@Provides. * 当使用@Provides方法创建对象时,该方法必须定义在Module类中,并且它必须加以@Provides注解, * 该方法的返回值类型就是被绑定的对象.当注入器需要该类型的实例时,它就会来调用该方法.注意:Provides和Provider的区别. * @Provides方法绑定方式是可以和注解绑定混合使用的.  * 如果在@Provides方法上有绑定注解(@AnnotationOne),Guice以绑定注解优先. * Guice在调用@Provides方法之前会先解析该方法的依赖. */public class MainTest {    public static void main(String[] args) {        Injector injector = Guice.createInjector(new MyModule());        MyService myService = injector.getInstance(MyService.class);        myService.service();        MyService myServiceOne = injector.getInstance(Key.get(MyService.class, AnnotationOne.class));        myServiceOne.service();        MyService myServiceTwo = injector.getInstance(Key.get(MyService.class, AnnotationTwo.class));        myServiceTwo.service();        System.out.println("-----------------@Provides的使用--------------------------");        Injector injector2 = Guice.createInjector(new MyModule2());        MyService myService2 = injector2.getInstance(MyService.class);        myService2.service();    }}/**==>one==>one==>two-----------------@Provides的使用--------------------------==>xxx*/

package com.ilucky.guice.test10;import com.google.inject.Binder;import com.google.inject.Key;import com.google.inject.Module;import com.google.inject.Provides;public class MyModule implements Module{    //默认使用AnnotationOne.    public void configure(Binder binder) {         binder.bind(MyService.class).to(Key.get(MyService.class, AnnotationOne.class));    }    @Provides @AnnotationOne    public MyService one() {        return new MyService("one");    }    @Provides @AnnotationTwo    public MyService two() {        return new MyService("two");    }}

package com.ilucky.guice.test10;import com.google.inject.Binder;import com.google.inject.Module;import com.google.inject.Provides;public class MyModule2 implements Module{    public void configure(Binder binder) {    }    @Provides     public MyService xxx() {        return new MyService("xxx");    }}

package com.ilucky.guice.test10;public class MyService {    private String type;    public MyService(String type) {        this.type = type;    }    public void service() {        System.out.println("==>" + type);    }}

package com.ilucky.guice.test10;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;import com.google.inject.BindingAnnotation;@Target({ ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD })@Retention(RetentionPolicy.RUNTIME)@BindingAnnotationpublic @interface AnnotationOne {}

package com.ilucky.guice.test10;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;import com.google.inject.BindingAnnotation;@Target({ ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD })@Retention(RetentionPolicy.RUNTIME)@BindingAnnotationpublic @interface AnnotationTwo {}

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