01_RxJava操作符示例程式碼
阿新 • • 發佈：2018-11-11
抽時間研究了下RxJava，因為網路博文講述描述性文字較多，示例較少，很多時候不知道怎麼開始入手學習RxJava，因此在此發文讓想入門的看了博文之後實操一下，步驟很簡單：
1.在網上下載一個RxJava的jar包，我找到一個1.1.5jar包，也不用管版本的高低，先入門是沒問題的，寫幾個例子一點問題沒有，什麼RxJava2，大家大可不必慌張去學習，研究低版本的，是讓我們知道低層版本是怎樣做的，在發展到RxJava2的時候，又做了哪些改進，所以遵從一個由低到高的順序，你不會吃虧的。（扯遠了）
2.在Eclipse裡面建一個java工程，新建一個libs目錄，將下載到的RxJava 的jar包放到該目錄下，然後新增到構建路徑（add lib to build path）.
3.接下來就可以建一個包，然後建一個類，開始在main()裡面寫示例程式碼了，學東西先讓它執行起來再看是怎麼回事兒。接下來貼一下我學習時寫的hello world與操作符使用的示例程式碼，供大家參考，希望對入門的人有所幫助。
package com.gdc.rxjava;
import java.util.ArrayList;
import java.util.concurrent.TimeUnit;
import rx.Observable;
import rx.Observable.OnSubscribe;
import rx.functions.Func0;
import rx.Subscriber;
public class HelloWorld {
public static void main(String[] args) {
// helloworld();
// create();
// just();
// from();
// defer();
// empty();
// never();
// throwtest();
// interval();
// range();
repeat();
}
private static void create() {
Observable.create(new OnSubscribe<String>() {
@Override
public void call(Subscriber<? super String> subscriber) {
subscriber.onNext("中華人民共和國 RxJava學習");
}
}).subscribe(new Subscriber<String>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(String arg0) {
System.out.println("onNext():" + arg0);
}
});
}
private static void just() {
Observable.just("中華人民共和國 RxJava學習").subscribe(new Subscriber<String>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(String arg0) {
System.out.println("onNext():" + arg0);
}
});
}
private static void from() {
// 1: 陣列、
// 2:列表
// 3:Iterable
// 4:Future
// 5:Future,Scheduler
// 6:Future,timout,timeUnit
Integer[] a = new Integer[] { 1, 2, 3, 4, 5, 6, 7 };
// 支援2
ArrayList<Integer> items = new ArrayList<Integer>();
items.add(1);
items.add(2);
items.add(3);
items.add(4);
items.add(5);
items.add(6);
Observable.from(items).subscribe(new Subscriber<Integer>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Integer arg0) {
System.out.println("onNext():" + arg0);
}
});
}
private static String valuestr;
private static void defer() {
// Observable observable = Observable.just(valuestr);
Observable observable = Observable.defer(new Func0<Observable<String>>() {
@Override
public Observable<String> call() {
return Observable.just(valuestr);
}
});
valuestr = "中華人民共和國RxJava學習";
observable.subscribe(new Subscriber<String>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(String arg0) {
System.out.println("onNext():" + arg0);
}
});
}
private static void empty() {
Observable.empty().subscribe(new Subscriber() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Object arg0) {
System.out.println("onNext()");
}
});
}
private static void never() {
Observable.never().subscribe(new Subscriber() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Object arg0) {
System.out.println("onNext()");
}
});
}
private static void throwtest() {
Observable.error(new NullPointerException()).subscribe(new Subscriber() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Object arg0) {
System.out.println("onNext()");
}
});
}
private static void interval(){
Observable.interval(1000,TimeUnit.MICROSECONDS).subscribe(new Subscriber() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Object arg0) {
System.out.println("onNext()");
}
});
}
private static void range(){
Observable observable = Observable.range(1, 5);
observable.subscribe(new Subscriber<Integer>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Integer arg0) {
System.out.println("onNext()" + arg0);
}
});
}
private static void repeat(){
Observable observable = Observable.range(1, 5).repeat(2);
observable.subscribe(new Subscriber<Integer>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError():" + arg0);
}
@Override
public void onNext(Integer arg0) {
System.out.println("onNext()" + arg0);
}
});
}
private static void helloworld() {
// s1.建立被觀察者
Observable myObservable = Observable.create(new OnSubscribe<String>() {
@Override
public void call(Subscriber<? super String> subscriber) {
subscriber.onNext("hello world!!!");
// subscriber.onCompleted();
throw new NullPointerException();
}
});
// s2.建立觀察者
Subscriber subscriber = new Subscriber<String>() {
@Override
public void onCompleted() {
System.out.println("onCompleted()");
}
@Override
public void onError(Throwable arg0) {
System.out.println("onError()");
}
@Override
public void onNext(String arg0) {
System.out.println("onNext():" + arg0);
}
};
// s3.訂閱事件
myObservable.subscribe(subscriber);
}
}