Guice 学习（五）多接口的实现（ Many Interface Implementation）

1、接口

/*
 * Creation : 2015年6月30日
 */
package com.guice.InterfaceManyImpl;

public interface Service {
    public void execute();
}

2、两个实现类

package com.guice.InterfaceManyImpl;

public class OneService implements Service {
    @Override
    public void execute() {
        System.out.println("Hello!  I'M Service 1!");

    }
}

package com.guice.InterfaceManyImpl;

public class TwoService implements Service {

    @Override
    public void execute() {
        System.out.println("Hello!  I'M Service 2!");

    }

}

3、两个注解类

package com.guice.InterfaceManyImpl;

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;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.FIELD, ElementType.PARAMETER })
@BindingAnnotation
public @interface One {
}

package com.guice.InterfaceManyImpl;

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;

@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.FIELD, ElementType.PARAMETER })
@BindingAnnotation
public @interface Two {

}

4、多接口实现測试类

package com.guice.InterfaceManyImpl;

import com.google.inject.Binder;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Module;

/*
 * 接口的多实现：
 * 此类的结构是注入了两个service服务，注解One和OneService关联。第二个和它一样
 */
public class InterfaceManyImpl {
    @Inject
    @One
    private Service oneService;
    @Inject
    @Two
    private Service twoService;

    public static void main(String[] args) {
        InterfaceManyImpl instance = Guice.createInjector(new Module() {

            @Override
            public void configure(Binder binder) {
                //让注解类和实现类绑定
                binder.bind(Service.class).annotatedWith(One.class).to(OneService.class);
                binder.bind(Service.class).annotatedWith(Two.class).to(TwoService.class);
            }
        }).getInstance(InterfaceManyImpl.class);

        instance.oneService.execute();
        instance.twoService.execute();
    }

}

5、无注解的多接口实现測试类

package com.guice.InterfaceManyImpl;

import com.google.inject.Binder;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Module;
import com.google.inject.name.Named;
import com.google.inject.name.Names;

/**
 * TODO : 程序猿比較懒，不想写注解来区分多个服务则能够使用Google提供的一个叫Names的模板来生成注解
 * @author E468380
 */
public class NoAnnotationMultiInterfaceServiceDemo {
    @Inject
    @Named("One")
    private static Service oneService;

    @Inject
    @Named("Two")
    private static Service twoService;

    public static void main(String[] args) {
        Guice.createInjector(new Module() {

            @Override
            public void configure(Binder binder) {
                // 这里不同
                binder.bind(Service.class).annotatedWith(Names.named("One")).to(OneService.class);
                binder.bind(Service.class).annotatedWith(Names.named("Two")).to(TwoService.class);
                binder.requestStaticInjection(NoAnnotationMultiInterfaceServiceDemo.class);
            }
        });
        NoAnnotationMultiInterfaceServiceDemo.oneService.execute();
        NoAnnotationMultiInterfaceServiceDemo.twoService.execute();

    }

}

6、静态的多接口实现測试类

问题（1）静态注入多个服务怎么写？

package com.guice.InterfaceManyImpl;

import com.google.inject.Binder;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Module;

/**
 * TODO :也能够静态注入多个服务
 *
 * @author E468380
 */
public class StaticMultiInterfaceServiceDemo {

    @Inject
    @One
    private static Service oneService;

    @Inject
    @One
    private static Service twoService;

    public static void main(String[] args) {
        Guice.createInjector(new Module() {

            @Override
            public void configure(Binder binder) {
                binder.bind(Service.class).annotatedWith(One.class).to(OneService.class);
                binder.bind(Service.class).annotatedWith(Two.class).to(TwoService.class);
                binder.requestStaticInjection(StaticMultiInterfaceServiceDemo.class);
            }
        });
        StaticMultiInterfaceServiceDemo.oneService.execute();
        StaticMultiInterfaceServiceDemo.twoService.execute();

    }

}
// 假设不小心一个属性绑定了多个接口怎么办？ --》不能够绑定多个服务。