Rxjava框架的使用

添加如下依赖即可开始使用：

compile 'io.reactivex.rxjava2:rxandroid:2.0.1'

map的使用，注意map是一对一，flatmap是一对多

String filePath = "/storage/emulated/0/1.jpg";///storage/emulated/0这个路径是手机内存的路径，不是存储卡的路径
Observable sender = Observable.just(filePath).subscribeOn(Schedulers.newThread()).observeOn(Schedulers.io()).map(new Function() {//这里的subscribeOn(Schedulers.newThread())是新创建一个线程来发射事件，.observeOn(Schedulers.io())是将接下来的map操作放在io线程上进行
            @Override
            public Bitmap apply(@NonNull String s) throws Exception {
                Log.i("xian", Thread.currentThread().getName());
                return BitmapFactory.decodeFile(s);
            }
        });
        Observer receiver = new Observer() {
            @Override
            public void onError(Throwable e) {

            }

            @Override
            public void onComplete() {

            }

            @Override
            public void onSubscribe(@NonNull Disposable d) {

            }

            @Override
            public void onNext(Bitmap bitmap) {
                imageView.setImageBitmap(bitmap);
                Log.i("xian", Thread.currentThread().getName());
            }
        };
        sender.observeOn(AndroidSchedulers.mainThread()).subscribe(receiver);//需要先添加Rxandroid库，才能使用AndroidSchedulers.mainThread()，先切换回主线程，然后执行receiver这个Observer中的代码
        Observable.just("dd").subscribe();

 Observable.just(1, 2, 3, 4).subscribe(new Consumer() {//Consumer是比Observer精简的
            @Override
            public void accept(Integer integer) throws Exception {
                Log.i("xinxi",integer+"");
            }
        });

 Observable observable = Observable.create(new ObservableOnSubscribe() {//自己创建Observable，没有用just，from之类的
            @Override
            public void subscribe(@NonNull ObservableEmitter e) throws Exception {
                e.onNext("R");
                e.onNext("x");
                e.onNext("j");
                e.onNext("a");
                e.onNext("v");
                e.onNext("a");
            }
        });
         Observer observer = new Observer() {
            @Override
            public void onSubscribe(@NonNull Disposable d) {

            }

            @Override
            public void onNext(@NonNull String s) {
                Log.i("xinxi", s);
            }

            @Override
            public void onError(@NonNull Throwable e) {

            }

            @Override
            public void onComplete() {

            }
        };
        observable.subscribe(observer);

repeat的用法

 Observable.just("1","2","3").repeat(3).subscribe(new Consumer() {//repeat是重复的次数
            @Override
            public void accept(String s) throws Exception {
                Log.i("hh",s);
            }
        });

repeatWhen的用法

Observable.just("1","2","3").repeatWhen(new Function, ObservableSource>() {
            @Override
            public ObservableSource apply(Observable