@Qualifier
@Retention(RetentionPolicy.RUNTIME)
public @interface A {}

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
public @interface B {}

@Module
public class SimpleModule {
 @Provides
 @A
 Cooker provideCookerA(){
 return new Cooker("James","Espresso");
 }

 @Provides
 @B
 Cooker provideCookerB(){
 return new Cooker("Karry","Machiato");
 }
}

public class ComplexMaker implements CoffeeMaker {
 Cooker cookerA;
 Cooker cookerB;
 @Inject
 public ComplexMaker(@A Cooker cookerA,@B Cooker cookerB){
 this.cookerA = cookerA;
 this.cookerB = cookerB;
 }
}

@Module
public class MainModule {
 @Provides
 @Named("red")
 public Cloth getRedCloth() {
 Cloth cloth = new Cloth();
 cloth.setColor("紅色");
 return cloth;
 }

 @Provides
 @Named("blue")
 public Cloth getBlueCloth() {
 Cloth cloth = new Cloth();
 cloth.setColor("藍色");
 return cloth;
 }

 @Provides
 public Clothes getClothes(@Named("blue") Cloth cloth){
 return new Clothes(cloth);
 }
}

public class MainActivity extends AppCompatActivity {
 ...
 @Inject
 @Named("red")
 Cloth redCloth;
 @Inject
 @Named("blue")
 Cloth blueCloth;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 ...
 tv.setText("我現(xiàn)在有" + redCloth + "和" + blueCloth );
 }
}

//PerActivity.java
@Scope
@Retention(RetentionPolicy.RUNTIME)
public @interface PerActivity {}

//ActivityModule.java
@Module
public class ActivityModule {
 @Provides
 CoffeeShop provideCoffeeShop(){
 return CoffeeShop.getInstance();//一個普通的單例
 }

 /**
 * 直接在這里說結(jié)果，@PerActivity是用@Scope注解的，除了在這里注解還需要在用到該Module類的Component的類名上方也要注解，然后該實例在注入到某個類里的時候用同一個Component就會不管有幾個字段都會只有一個實例。注意：如果用不同的Component實例的話仍然會新的CookerFactory實例，單例CookerFactory只存在一個Component實例里。所以叫局部單例。
 */
 @Provides
 @PerActivity
 CookerFactory provideCookerFactory(){
 return new CookerFactory();
 }

 @Provides
 CookerFactoryMulty provideCookerFactoryMulty(){
 return new CookerFactoryMulty();//非單例
 }
}

//CoffeeShop.java
public class CoffeeShop {
 private static CoffeeShop INSTANCE;
 private CoffeeShop(){
 Log.d("TAG","CoffeeShop New Instance");
 }

 public static CoffeeShop getInstance(){
 if(INSTANCE == null){
 INSTANCE = new CoffeeShop();
 }
 return INSTANCE;
 }
}

//CookerFactory.java
public class CookerFactory {
 public CookerFactory(){
 Log.d("TAG","CookerFactory New Instance");
 }
}

//CookerFactoryMulty.java
public class CookerFactoryMulty {
 public CookerFactoryMulty(){
 Log.d("TAG","CookerFactoryMulty New Instance");
 }
}

//除了在Module的Provides方法里寫上@Scope還需要在Component類名上方寫上，這里自定義的@Scope名字叫PerActivity
@PerActivity
@Component(modules = {ActivityModule.class})
public interface ActivityComponent {
 void inject(MainActivity simpleActivity);
}

public class MainActivity extends Activity {
 ActivityComponent activityComponent;
 @Inject
 CoffeeShop coffeeShop1;

 @Inject
 CoffeeShop coffeeShop2;

 @Inject
 CookerFactory cookerFactory1;

 @Inject
 CookerFactory cookerFactory2;

 @Inject
 CookerFactoryMulty cookerFactoryMulty1;

 @Inject
 CookerFactoryMulty cookerFactoryMulty2;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 activityComponent = DaggerActivityComponent.builder()
 //下面這句話可以不寫，因為Module有默認(rèn)構(gòu)造函數(shù)。如果Module的構(gòu)造器里有參數(shù)，并且該參數(shù)不是注入進去的，就需要用類似下面的方法手動設(shè)置實例到Component中
 .activityModule(provideModule())
 .applicationComponent(MyApplication.getComponent()).build();
 activityComponent.inject(this);
 coffeeFactory.run();
 }
 
 private ActivityModule provideModule(){
 return new ActivityModule();
 }
}

07-11 16:53:27.978 1927-1927/? D/TAG﹕ CoffeeShop New Instance
07-11 16:53:27.978 1927-1927/? D/TAG﹕ CookerFactory New Instance
07-11 16:53:27.978 1927-1927/? D/TAG﹕ CookerFactoryMulty New Instance
07-11 16:53:27.978 1927-1927/? D/TAG﹕ CookerFactoryMulty New Instance

//Person.java
public class Person {
}

//PerActivity.java
@Scope
@Retention(RetentionPolicy.RUNTIME)
public @interface PerActivity {}

//BaseModule.java
@Module
public class BaseModule {

 @Singleton
 @Provides
 public Person providePerson(){
 return new Person();
 }
}

//Module1.java
@Module
public class Module1 {

}

//Module2.java
@Module
public class Module2 {

}

//BaseComponent.java
@Singleton
@Component(modules = BaseModule.class)
public interface BaseComponent {
 public Person providePerson();
}

//Component1.java
@PerActivity
//@Singleton
//因為依賴（dependencies）的BaseComponent中用到了@Singleton，所以這個Component就不能再用了，否則會編譯錯誤，為什么這么設(shè)計還不是很清楚
@Component(modules = Module1.class,dependencies = BaseComponent.class)
public interface Component1 {
 void inject(TestScopeActivity1 simpleActivity);
}

//Component2.java
@PerActivity
//@Singleton 為什么不能用？原理同上
@Component(modules = Module2.class,dependencies = BaseComponent.class)
public interface Component2 {
 void inject(TestScopeActivity2 simpleActivity);
}

//MyApplication.java
public class MyApplication extends Application {

 private static BaseComponent baseComponent;

 @Override
 public void onCreate() {
 super.onCreate();
 baseComponent = DaggerBaseComponent.builder().build();
 }

 public static BaseComponent getBaseComponent() {
 return baseComponent;
 }
}

//TestScopeActivity1.java
public class TestScopeActivity1 extends Activity {

 @Inject
 Person p = null;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 DaggerComponent1.builder().baseComponent(MyApplication.getBaseComponent()).build().inject(this);
 TextView textView = findViewById(R.id.textView);
 textView.setText(p.toString());
 textView.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
  startActivity(new Intent(TestScopeActivity1.this,TestScopeActivity2.class));
  }
 });
 }
}

//TestScopeActivity2.java
public class TestScopeActivity2 extends Activity {

 @Inject
 Person p = null;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 DaggerComponent2.builder().baseComponent(MyApplication.getBaseComponent()).build().inject(this);
 TextView textView = findViewById(R.id.textView);
 textView.setText(p.toString());
 }
}