Android自助餐之RxJava手冊

• Android自助餐之RxJava手冊
  • • 下載完整原始碼
    • 觀察者
    • 被觀察物件
    • 方法封裝
    • 型別轉換
    • 執行緒控制

下載完整原始碼

觀察者

1. Observer
   
   • onNext()
   • onCompleted();
   • onError();
2. Subscriber
   
   • 繼承Observer
   • onStart();在開始傳送事件前
   • subscriber.unsubscribe();取消訂閱

被觀察物件

1. Observable.create(Observable.OnSubscribe());

   Observable.create(new Observable.OnSubscribe<String>(){
   
    @Override
    public void call(Subscriber<? super String> subscriber) {
        subscriber.onNext("a");
        subscriber.onNext("aa"
    
   );
        subscriber.onNext("aaa");
        subscriber.onCompleted();
    }
   });

2. Observable.just();
   
Observable.just("a","aa","aaa");

3. Observable.from();
   
ArrayList<String> strings = new ArrayList<>();
Observable.from(strings);


方法封裝

1. FuncX
   封裝帶有x個引數的帶返回值方法。

2. ActionX
   封裝帶有x個引數的無返回值方法。

   public static void demoOfAction() {
       Observable.from(DataManager.getInstance().getData())
               .subscribe(new Action1<String>() {
                   @Override
                   public void call(String s) {
                       LogUtil.e("next",s);
   
                   }
               });//將事件發給訂閱者
   }

型別轉換

1. map()一對一轉換

   public static void demoOfMap(){
       Observable.from(DataManager.getInstance().getData())
               .map(new Func1<String, Car>() {
                   private int count=0;
                   @Override
                   public Car call(String s) {
                       return new Car(count++,s);
                   }
               })//將事件內容轉型
               .subscribe(new Action1<Car>() {
                   @Override
                   public void call(Car car) {
                       LogUtil.e("next",car.getStyle());
   
                   }
               });//將事件發給訂閱者
   }

2. flatMap()一對多轉換
   
public static void demoOfFlatMap() {
//一個人有多輛車，輸出每個人的每個車
Observable.from(DataManager.getInstance().getPserson())
.flatMap(new Func1<Person, Observable<Car>>() {
@Override
public Observable<Car> call(Person person) {
return Observable.from(person.getCars());
}
})
.subscribe(new Action1<Car>() {
@Override
public void call(Car car) {
LogUtil.e("car",car.getStyle());
}
});
}


執行緒控制

1. subscribeOn()指定被觀察物件執行緒
2. observeOn()指定觀察者執行緒
3. Schedulers.immediate();當前執行緒
4. Schedulers.newThread();新開一個執行緒
5. Schedulers.io();與newThread()差不多，但io()中內建無數量上限的執行緒池。注意不要把計算操作放在這裡，避免建立多餘的執行緒。
6. Schedulers.computation();與io()的區別在於其執行緒池大小固定，大小為CPU核心數。注意不要把I/O操作放在這裡，避免浪費CPU。
7. AndroidSchedulers.mainThread();UI執行緒。

public static void demoOfScheduler() {
    //建立觀察者
    Subscriber<String> subscriber = new Subscriber<String>() {
        @Override
        public void onCompleted() {}

        @Override
        public void onError(Throwable e) {}

        @Override
        public void onNext(String s) {
            LogUtil.e("next-thread",Thread.currentThread().getId()+"<->"+Thread.currentThread().getName());
        }
    };

    //建立被觀察物件
    Observable.OnSubscribe<String> observable = new Observable.OnSubscribe<String>() {

        @Override
        public void call(Subscriber<? super String> subscriber) {
            LogUtil.e("send-thread",Thread.currentThread().getId()+"<->"+Thread.currentThread().getName());
            subscriber.onNext("gfsdh");
            subscriber.onNext("dfshs");
            subscriber.onNext("fdsa");
            subscriber.onCompleted();
        }
    };

    //開始搞起
    Observable.create(observable)
            .subscribeOn(Schedulers.io())//指定事件發生執行緒
            .observeOn(Schedulers.newThread())//指定下一個事件處理執行緒
            .map(new Func1<String, Car>() {
                private int count=0;
                @Override
                public Car call(String s) {
                    LogUtil.e("to-car-thread",Thread.currentThread().getId()+"<->"+Thread.currentThread().getName());
                    return new Car(count++,s);
                }
            })//將事件內容轉型
            .observeOn(Schedulers.newThread())//指定一下一個事件處理執行緒
            .map(new Func1<Car, Person>() {
                private int count=0;
                @Override
                public Person call(Car car) {
                    LogUtil.e("to-person-thread",Thread.currentThread().getId()+"<->"+Thread.currentThread().getName());
                    return new Person(car.getStyle(),count++);
                }
            })//將事件內容轉型
            .observeOn(Schedulers.computation())//指定一下一個事件處理執行緒
            .map(new Func1<Person, String>() {
                @Override
                public String call(Person person) {
                    LogUtil.e("to-string-thread",Thread.currentThread().getId()+"<->"+Thread.currentThread().getName());
                    return person.getName();
                }
            })//將事件內容轉型
            .observeOn(AndroidSchedulers.mainThread())//指定一下一個事件處理執行緒
            .subscribe(subscriber);//將事件發給訂閱者
}

E/send-thread: 6412<->RxCachedThreadScheduler-1
E/to-car-thread: 6410<->RxNewThreadScheduler-2
E/to-car-thread: 6410<->RxNewThreadScheduler-2
E/to-person-thread: 6409<->RxNewThreadScheduler-1
E/to-car-thread: 6410<->RxNewThreadScheduler-2
E/to-person-thread: 6409<->RxNewThreadScheduler-1
E/to-person-thread: 6409<->RxNewThreadScheduler-1
E/to-string-thread: 6408<->RxComputationThreadPool-3
E/to-string-thread: 6408<->RxComputationThreadPool-3
E/to-string-thread: 6408<->RxComputationThreadPool-3
E/next-thread: 1<->main
E/next-thread: 1<->main
E/next-thread: 1<->main