Dragger2的使用

依赖

compile 'com.google.dagger:dagger:2.11'
annotationProcessor 'com.google.dagger:dagger-compiler:2.11'

compile 'com.google.dagger:dagger-android:2.11'
// if you use the support libraries
compile 'com.google.dagger:dagger-android-support:2.11' 
annotationProcessor 'com.google.dagger:dagger-android-processor:2.11'

依赖冲突处理：

android{
    configurations.all {
        resolutionStrategy.force 'com.google.code.findbugs:jsr305:3.0.2'
    }
}

初级用法

/** Worm.java **/
public class Worm {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

/** WormModule **/
@Module
public class WormModule {
    private String name;

    public AppleModule(String name) {
        this.name = name;
    }

    @Provides
    public String provideName() {
        return name;
    }

    @Provides
    public Worm provideWorm(String name) {
        Worm worm = new Worm();
        worm.setName(name);
        return worm;
    }
}

/** WormComponent.java **/
@Component(modules = {WormModule.class})
public interface WormComponent {
    Worm provideWorm();
}

WormModule wormModule = new WormModule("goFuckYouSelf");
WormComponent wormComponent = DaggerWormComponent.builder().wormModule(wormModule).build();
System.out.println(wormComponent.provideWorm().getName());

多个Module

/** Apple2Module.java **/
@Module
public class Apple2Module {

    @Provides
    public Apple provideApple(String color) {
        Apple apple = new Apple();
        apple.setColor("bitch");
        return apple;
    }
}

/** MultComponent.java **/
@Component(modules = {Apple2Module.class, WormModule.class})
public interface MultComponent {
    Worm provideWorm();

    Apple provideApple();
}

/** MultProgram.java **/
public class MultProgram {
    public void mult() {
        MultComponent component = DaggerMultComponent.builder()
                .apple2Module(new Apple2Module())
                .wormModule(new WormModule())
                .build();
        System.out.println(component.provideApple().getColor());
        System.out.println(component.provideWorm().getName());
    }
}

MultComponent依赖的多个Module里面，不能有返回相同类型的方法。

Field Injection

/** InjectModule.java **/
@Module
public class InjectModule {
    @Provides
    public Worm provideWorm() {
        Worm worm = new Worm();
        worm.setName("another worm");
        return worm;
    }
}

/** InjectComponent.java **/
@Component(modules = {InjectModule.class})
public interface InjectComponent {
    void inject(InjectProgram program);
}

/** InjectProgram.java **/
public class InjectProgram {
    @Inject
    public Worm worm;

    public void worm() {
        InjectComponent component = DaggerInjectComponent.builder().injectModule(new InjectModule()).build();
        component.inject(this);
        System.out.println(worm.getName());
    }
}

Singleton注解

/** SingleWormModule.java **/
@Module
public class SingleWormModule {
    @Provides
    public String provideName() {
        return "goFuckYouSelf";
    }

    @Provides
    @Singleton
    public Worm provideWorm(String name) {
        Worm worm = new Worm();
        worm.setName(name);
        return worm;
    }
}

/** SingleWormModule.java **/
@Component(modules = {SingleWormModule.class})
@Singleton
public interface SingleWormComponent {
    Worm provideSingleWorm();
}

/** SingleProgram.java **/
public class SingleProgram {
    public void singleWorm() {
        SingleWormComponent component = DaggerSingleWormComponent.builder().singleWormModule(new SingleWormModule()).build();
        Worm worm1 = component.provideSingleWorm();
        Worm worm2 = component.provideSingleWorm();
        System.out.println(worm1 == worm2);
    }
}

/** output **/
true

Module和Component都要加，不然无效。如果Module加了，Component没加，则代码生成时会出错。