Android-->RxJava/RxAndroid 入门初体验

缩短篇幅,直入主题:
RxJava 主要的作用就是链式完成异步操作,并且非常强大.

在Android项目中添加

    compile 'io.reactivex:rxjava:1.1.0'
    compile 'io.reactivex:rxandroid:1.1.0'

写法:

 //1:定义一个 可以被观察的对象
 Observable observable = Observable.create(new Observable.OnSubscribe<String>() {

     @Override
     public void call(Subscriber<? super String> subscriber) {
         subscriber.onNext("Hello");
         subscriber.onNext("Hi");
         subscriber.onCompleted();
     }
 });

 //等效以上写法
 Observable observable1 = Observable.just("Hello", "Hi", "Aloha");

 //等效以上写法
 String[] words = {"Hello", "Hi", "Aloha"};
 Observable observable2 = Observable.from(words);

 //2:将可以被观察的对象,交给观察者执行
 observable.subscribe(new Observer<String>() {
     @Override
     public void onCompleted() {
         L.e("onCompleted");
     }

     @Override
     public void onError(Throwable e) {

     }

     @Override
     public void onNext(String s) {
         L.e("onNext -- " + s);
     }
 });

基本-使用示例:

  Observable.just("Hello").subscribe(new Action1<String>() {
      @Override
      public void call(String s) {
          Log.e("RSenL", "call -- " + s);//将在调用者线程执行
      }
  });

  Observable.just("Hello")
          .observeOn(AndroidSchedulers.mainThread())
          .subscribe(new Action1<String>() {
      @Override
      public void call(String s) {
          Log.e("RSenL", "call -- " + s);//将在主线程执行
      }
  });

 Observable.just("Hello")
         .observeOn(Schedulers.newThread())
         .subscribe(new Action1<String>() {
     @Override
     public void call(String s) {
         Log.e("RSenL", "call -- " + s);//将在新线程执行
     }
 });

前台调用-后台执行 写法:

   Observable.just("Hello")
           .doOnSubscribe(new Action0() {
               @Override
               public void call() {
                   Log.e("RSenL", "call -- On Main Thread" );//主线程
               }
           })
           .subscribeOn(AndroidSchedulers.mainThread())//必须此行,顺序必须在后
           .observeOn(Schedulers.newThread())
           .subscribe(new Action1<String>() {
       @Override
       public void call(String s) {
           Log.e("RSenL", "call -- " + s);//新线程
       }
   });

后台调用-前台执行 写法:

 Observable.just("Up Image").doOnSubscribe(new Action0() {
       @Override
       public void call() {
           try {
               Log.e("1", "tid:" + Thread.currentThread().getId());//io线程
               Thread.sleep(2000);
           } catch (InterruptedException e) {
               e.printStackTrace();
           }
       }
   }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread())//必须在后面
           .subscribe(new Action1<String>() {
               @Override
               public void call(String s) {
                   try {
                       Log.e("2", "tid:" + Thread.currentThread().getId());//主线程
                       Thread.sleep(2000);
                   } catch (InterruptedException e) {
                       e.printStackTrace();
                   }
               }
           }); 
    //或者 ---------------------
Observable.just("Hello")
   .map(new Func1<String, String>() {
           @Override
           public String call(String s) {
               Log.e("RSenL", "thread id:" + Thread.currentThread().getId());//新线程
               return null;
           }
       })
       .subscribeOn(Schedulers.newThread())
       .observeOn(AndroidSchedulers.mainThread())
       .subscribe(new Action1<String>() {
           @Override
           public void call(String s) {
               Log.e("RSenL", "thread id:" + Thread.currentThread().getId());//主线程
           }
       });

Rx 线程控制, 写法:

Observable.just("a", "b", "c").subscribeOn(Schedulers.io())//决定提交在io线程
          .doOnSubscribe(new Action0() {
              @Override
              public void call() {
                  Log.e("0", "tid:" + Thread.currentThread().getId());//主线程

              }
          })
          .subscribeOn(AndroidSchedulers.mainThread())
          .observeOn(Schedulers.newThread()).map(new Func1<String, String>() {
      @Override
      public String call(String s) {
          Log.e("1", "tid:" + Thread.currentThread().getId());//新线程

          return null;
      }
  }).observeOn(AndroidSchedulers.mainThread()).map(new Func1<String, String>() {
      @Override
      public String call(String s) {
          Log.e("2", "tid:" + Thread.currentThread().getId());//主线程
          return null;
      }
  }).observeOn(Schedulers.newThread()).map(new Func1<String, String>() {
      @Override
      public String call(String s) {
          Log.e("3", "tid:" + Thread.currentThread().getId());//新线程
          return null;
      }
  }).filter(new Func1<String, Boolean>() {
      @Override
      public Boolean call(String s) {
          Log.e("4-filter", "tid:" + Thread.currentThread().getId());//新线程
          return true;
      }
  }).take(4)
          .observeOn(Schedulers.io()).map(new Func1<String, Object>() {
      @Override
      public Object call(String s) {
          Log.e("4", "tid:" + Thread.currentThread().getId());//io线程
          return null;
      }
  }).subscribe(new Action1<Object>() {
      @Override
      public void call(Object o) {
          try {
              Thread.sleep(2000);
          } catch (InterruptedException e) {
              e.printStackTrace();
          }
          Log.e("5", "tid:" + Thread.currentThread().getId());//io线程
      }
  });

RxJava的异常捕捉:

Observable.create(new Observable.OnSubscribe<String>() {
    @Override
    public void call(Subscriber<? super String> subscriber) {
        p("-->OnSubscribe");
        subscriber.onNext("next");
        subscriber.onNext("next");
        subscriber.onNext("next");
        subscriber.onNext("next");
        int i = 100/0;
        subscriber.onCompleted();//必须放在最后,否则异常捕捉不到
    }
}).subscribe(new Subscriber<String>() {
    @Override
    public void onCompleted() {
        p("-->onCompleted");
    }

    @Override
    public void onError(Throwable throwable) {
        p("-->onError");
    }

    @Override
    public void onNext(String s) {
        p("-->onNext");
    }
});

Observable.just("--").doOnCompleted(new Action0() {
    @Override
    public void call() {
        bottomTip.setText("-->doOnCompleted");
        p("-->doOnCompleted");
    }
}).doOnError(new Action1<Throwable>() {
    @Override
    public void call(Throwable throwable) {
        bottomTip.setText("-->doOnError");
        p("-->doOnError");
    }
}).doOnNext(new Action1<String>() {
    @Override
    public void call(String s) {
        bottomTip.setText("-->doOnNext");
        p("-->doOnNext");
// int i = 100/0;
    }
}).subscribe(new Action1<String>() {
    @Override
    public void call(String s) {
        bottomTip.setText("-->subscribe");
// int i = 100/0;
        p("-->subscribe");
    }
}, new Action1<Throwable>() {
    @Override
    public void call(Throwable throwable) {
        p("-->onError");
    }
});

未完待续…

参考文献

http://gank.io/post/560e15be2dca930e00da1083
http://segmentfault.com/a/1190000004160294

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