RxJava入门(5):功能性操作符

新年快乐,开工大吉

filter 过滤范围外的数据
Observable.just(1,2,3,4,5)

               .filter(new Predicate() {

                   @Override

                  public boolean test(Integer integer) throws Exception {

                              Log.e("yzh","filter");

                                return integer>3;

              }

              }).subscribe(new Observer() {

           @Override

          public void onSubscribe(Disposable d) {



           }

           @Override

           public void onNext(Integer integer) {

               Log.e("yzh","onNext--"+integer);

            }



           @Override

            public void onError(Throwable e) {

           }



           @Override

            public void onComplete() {



           }

        });

打印结果

       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: filter
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: filter
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: filter
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: filter
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: onNext--4
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: filter
       02-07 15:35:28.549 22207-22207/com.example.issuser.rxtest E/yzh: onNext--5
ofType 过滤掉某些类型的数据
        Observable.just("1",2,"abv",5,"qqq")

                .ofType(Integer.class)

                .subscribe(new Consumer() {

                    @Override

                    public void accept(Integer integer) throws Exception {

                            Log.e("yzh","accept--"+integer);

                    }

                }) ;

打印结果

 02-07 15:40:03.320 22735-22735/com.example.issuser.rxtest E/yzh: accept--2
 02-07 15:40:03.320 22735-22735/com.example.issuser.rxtest E/yzh: accept--5
skip去掉第一个数据 skiplast去掉最后一个数据
   Observable.intervalRange(0,5,1,1, TimeUnit.SECONDS)
                      .skip(1)
                      .skipLast(1)
                      .subscribe(new Consumer() {
                            @Override
                            public void accept(Long integer)throws Exception {
                                  Log.e("yzh","accept--"+integer);
                          }
});

打印结果

02-07 15:59:26.198 24724-24765/com.example.issuser.rxtest E/yzh: accept--1
02-07 15:59:27.198 24724-24765/com.example.issuser.rxtest E/yzh: accept--2
02-07 15:59:28.198 24724-24765/com.example.issuser.rxtest E/yzh: accept--3
distinct去掉重复数据
   Observable.just(1,2,3,2,1)
                     .distinct()
                    .subscribe(new Consumer() {
                        @Override
                        public void accept(Integer integer)throws Exception {
                              Log.e("yzh","accept--"+integer);
                    }
});

打印结果

accept--1
accept--2
accept--3
delay 使得被观察者延迟一段时间发送
  Observable.just(1,2,3)
                .delay(3, TimeUnit.SECONDS)
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {
                        Log.e("yzh","onSubscribe");
                    }

                    @Override
                    public void onNext(Integer integer) {
                        Log.e("yzh","onNext--"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });

打印结果

02-23 15:21:24.146 9436-9436/com.example.issuser.rxtest E/yzh: onSubscribe
02-23 15:21:27.148 9436-9478/com.example.issuser.rxtest E/yzh: onNext--1
02-23 15:21:27.148 9436-9478/com.example.issuser.rxtest E/yzh: onNext--2
02-23 15:21:27.148 9436-9478/com.example.issuser.rxtest E/yzh: onNext--3
do 在某个事件的生命周期中调用
 Observable.create(new ObservableOnSubscribe() {

            @Override
            public void subscribe(ObservableEmitter e) throws Exception {
                e.onNext(1);
                e.onNext(2);
                e.onNext(3);
                e.onError(new Throwable("发生错误了"));
            }
        })
                //当Observable每发送1次数据事件就会调用1次
                .doOnEach(new Consumer>() {
            @Override
            public void accept(Notification integerNotification) throws Exception {
                Log.e("yzh","doOnEach---"+integerNotification.getValue());
            }
        })
                //执行Next事件前调用
                .doOnNext(new Consumer() {
                    @Override
                    public void accept(Integer integer) throws Exception {
                        Log.e("yzh","doOnNext--"+integer);
                    }
                })
                //执行Next事件后调用
                .doAfterNext(new Consumer() {
                    @Override
                    public void accept(Integer integer) throws Exception {
                        Log.e("yzh","doAfterNext--"+integer);
                    }
                })
                //observable发送事件完毕后调用
                .doOnComplete(new Action() {
                    @Override
                    public void run() throws Exception {
                        Log.e("yzh","doOnComplete");
                    }
                })
                //observable发送错误事件时调用
                .doOnError(new Consumer() {
                    @Override
                    public void accept(Throwable throwable) throws Exception {
                        Log.e("yzh","doOnError--"+throwable.getMessage());
                    }
                })
                //观察者订阅时调用
                .doOnSubscribe(new Consumer() {
                    @Override
                    public void accept(Disposable disposable) throws Exception {
                        Log.e("yzh","donOnSubscribe");
                    }
                })
                //observable发送事件完毕后调用 无论正常发送完毕/异常终止
                .doAfterTerminate(new Action() {
                    @Override
                    public void run() throws Exception {
                        Log.e("yzh","doAfterTerminate");
                    }
                })
                //最后执行
                .doFinally(new Action() {
                    @Override
                    public void run() throws Exception {
                        Log.e("yzh","doFinally");
                    }
                })
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {
                    }

                    @Override
                    public void onNext(Integer integer) {
                        Log.e("yzh","onNext--"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onComplete() {

                    }
                });

打印结果

 02-23 11:27:09.946 31016-31016/com.example.issuser.rxtest E/yzh: donOnSubscribe
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnEach---1
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnNext--1
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: onNext--1
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doAfterNext--1
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnEach---2
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnNext--2
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: onNext--2
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doAfterNext--2
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnEach---3
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnNext--3
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: onNext--3
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doAfterNext--3
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnEach---null
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doOnError--发生错误了
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doFinally
        02-23 11:27:09.947 31016-31016/com.example.issuser.rxtest E/yzh: doAfterTerminate
onErrorReturn 遇到错误时,发送1个特殊事件 ,然后 正常终止
 Observable.create(new ObservableOnSubscribe() {
            @Override
            public void subscribe(ObservableEmitter e) throws Exception {
                e.onNext(1);
                e.onNext(2);
                e.onError(new Throwable("发生错误了"));
            }
        })
                //遇到错误时,发送一个特殊事件&正常终止
                .onErrorReturn(new Function() {
                    @Override
                    public Integer apply(Throwable throwable) throws Exception {
                        Log.e("yzh","onErrorReturn--"+throwable.getMessage());

                        return 123;
                    }
                })
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(Integer integer) {
                            Log.e("yzh","onNext--"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.e("yzh","onError--"+e.toString());
                    }

                    @Override
                    public void onComplete() {
                        Log.e("yzh","onComplete");
                    }
                });

打印结果

 02-23 11:46:07.620 2761-2761/com.example.issuser.rxtest E/yzh: onNext--1
        02-23 11:46:07.620 2761-2761/com.example.issuser.rxtest E/yzh: onNext--2
        02-23 11:46:07.620 2761-2761/com.example.issuser.rxtest E/yzh: onErrorReturn--发生错误了
        02-23 11:46:07.620 2761-2761/com.example.issuser.rxtest E/yzh: onNext--123
        02-23 11:46:07.620 2761-2761/com.example.issuser.rxtest E/yzh: onComplete
onErrorResumeNext 发送一个新的observable
Observable.create(new ObservableOnSubscribe() {
            @Override
            public void subscribe(ObservableEmitter e) throws Exception {
                e.onNext(1);
                e.onNext(2);
                e.onError(new Exception("发生错误了"));
            }
        })
                //遇到错误时,发送1个新的Observable 不分Throwable 和Exception
                .onErrorResumeNext(new Function>() {
                    @Override
                    public ObservableSource apply(Throwable throwable) throws Exception {
                        Log.e("yzh","onErrorResumeNext--"+throwable.getMessage());
                        return Observable.just(3,4);
                    }
                })
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(Integer integer) {
                        Log.e("yzh","onNext--"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.e("yzh","onError--"+e.getMessage());
                    }

                    @Override
                    public void onComplete() {

                    }
                });

打印结果

注意 被观察者中发送onError事件时,不区分Throwable和Exception
02-23 11:59:30.439 5596-5596/? E/yzh: onNext--1
02-23 11:59:30.439 5596-5596/? E/yzh: onNext--2
02-23 11:59:30.439 5596-5596/? E/yzh: onErrorResumeNext--发生错误了
02-23 11:59:30.439 5596-5596/? E/yzh: onNext--3
02-23 11:59:30.439 5596-5596/? E/yzh: onNext--4
onExceptionResumeNext与onErrorResumeNext 差不多,但是区分Throwable和Exception
Observable.create(new ObservableOnSubscribe() {
            @Override
            public void subscribe(ObservableEmitter e) throws Exception {
                e.onNext(1);
                e.onNext(2);
                e.onError(new Exception("发生错误了"));
            }
        })
                .onExceptionResumeNext(new ObservableSource() {
                    @Override
                    public void subscribe(Observer observer) {
                        observer.onNext(11);
                        observer.onNext(22);
                        observer.onComplete();
                    }
                })
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(Integer integer) {
                        Log.e("yzh","onNext--"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.e("yzh","onError--"+e.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.e("yzh","onComplete");
                    }
                });

打印结果

注意区分Throwable和Exception的不同
 Throwable
        02-23 14:38:58.163 30725-30725/com.example.issuser.rxtest E/yzh: onNext--1
        02-23 14:38:58.163 30725-30725/com.example.issuser.rxtest E/yzh: onNext--2
        02-23 14:38:58.163 30725-30725/com.example.issuser.rxtest E/yzh: onError--发生错误了
   Exception
   onNext--1
   onNext--2
   onNext--1
   onNext--2
   onComplete
retry 重试,即当出现错误时,让被观察者(Observable)重新发射数据,类似作用还有repeat
Observable.create(new ObservableOnSubscribe() {
            @Override
            public void subscribe(ObservableEmitter e) throws Exception {
                e.onNext(1);
                e.onNext(2);
                e.onError(new Exception("发生错误了"));
                e.onNext(3);
            }
        })
                .retry()
                .subscribe(new Observer() {
                    @Override
                    public void onSubscribe(Disposable d) {

                    }

                    @Override
                    public void onNext(Integer integer) {
                        Log.e("yzh","onNext-"+integer);
                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.e("yzh","onError--"+e.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.e("yzh","onComplete");
                    }
                });

打印结果

 3 14:45:31.130 31188-31188/com.example.issuser.rxtest E/yzh: onNext-1
        02-23 14:45:31.130 31188-31188/com.example.issuser.rxtest E/yzh: onNext-2
        02-23 14:45:31.130 31188-31188/com.example.issuser.rxtest E/yzh: onNext-1
        02-23 14:45:31.130 31188-31188/com.example.issuser.rxtest E/yzh: onNext-2
        .....无限循环

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