安卓中Rxjava
RxJava的核心原理其实就是典型的响应者模式，这并不难，但是它很巧妙的把这种响应者模式进行了链式的连接，这应该就是一种响应式编程的方式了吧。我把整个学习过程分成了三步，一步一步解密RxJava（代码尽量贴近RxJava源码）。同时为了练习Kotlin，因此决定用Kotlin来进行书写。
Observable 即被观察者，它决定什么时候触发事件以及触发怎样的事件。 RxJava 使用 create() 方法来创建一个 Observable ，并为它定义事件触发规则
public class Rxjava {
public static void main(String[] args) {
/* new Observable(){
@Override
protected void subscribeActual(Observer observer) {
observer.onNext("玻璃瓶");
observer.onNext("啤酒瓶");
observer.onComplete();
}
}.subscribe(new Observer() {
@Override
public void onSubscribe(Disposable d) {
}
@Override
public void onNext(String s) {
System.out.println("接收到了：" + s);
}
@Override
public void onError(Throwable e) {
}
@Override
public void onComplete() {
System.out.println("接收数据完毕");
}
});*/
// mapOpretor();
// flatMapOpretor();
// groupByOperator();
// filterOperator();
// distinctOperator();
// ignoreElements();
// elementAtOperator();
windowOperator();
}
//map操作符
public static void mapOpretor(){
Observable.just("HELLO")
.map(new Function() {
@Override
public String apply(String s) throws Exception {
return s.toLowerCase();
}
})
.map(new Function() {
@Override
public String apply(String s) throws Exception {
return s + ",world";
}
})
.subscribe(new Observer() {
@Override
public void onSubscribe(Disposable d) {
}
@Override
public void onNext(String s) {
System.out.println("接收到的数据是:" + s);
}
@Override
public void onError(Throwable e) {
}
@Override
public void onComplete() {
}
});
}
//flatMap操作符
public static void flatMapOpretor() {
User user = new User();
user.userName = "zhangsan";
user.addresss = new ArrayList<>();
User.Address address1 = new User.Address();
// User.Address address1 = new User.Address();
address1.street = "上地九街";
address1.city = "北京";
user.addresss.add(address1);
User.Address address2 = new User.Address();
address2.street = "上地十街";
address2.city = "上海";
user.addresss.add(address2);
/*Observable.just(user)
.map(new Function>() {
@Override
public List apply(User user) throws Exception {
return user.addresss;
}
}).subscribe(new Consumer>() {
@Override
public void accept(List addresses) throws Exception {
for (int i = 0; i < addresses.size(); i++) {
System.out.println("地址是：" + addresses.get(i).street);
}
}
});*/
Observable.just(user)
.flatMap(new Function>() {
@Override
public ObservableSource apply(User user) throws Exception {
return Observable.fromIterable(user.addresss);
}
})
.subscribe(new Consumer() {
@Override
public void accept(User.Address address) throws Exception {
System.out.println("地址是：" + address.street);
}
});
}
//groupBy操作符
public static void groupByOperator(){
Observable
.range(1,8)
.groupBy(new Function() {
@Override
public String apply(Integer integer) throws Exception {
return (integer % 2 == 0)? "偶数组":"奇数组";
}
}).subscribe(new Consumer>() {
@Override
public void accept(final GroupedObservable stringIntegerGroupedObservable) throws Exception {
if(stringIntegerGroupedObservable.getKey().equals("奇数组")){
stringIntegerGroupedObservable.subscribe(new Consumer() {
@Override
public void accept(Integer integer) throws Exception {
System.out.println(stringIntegerGroupedObservable.getKey() + "member:" + integer);
}
});
}/*else if(stringIntegerGroupedObservable.getKey().equals("偶偶组")){
stringIntegerGroupedObservable.subscribe(new Consumer() {
@Override
public void accept(Integer integer) throws Exception {
System.out.println(stringIntegerGroupedObservable.getKey() + "member:" + integer);
}
});
}*/
System.out.println();
}
});
}
//filter操作符
public static void filterOperator(){
Observable.just(1,8,20,3,50,4,6,100)
.filter(new Predicate() {
@Override
public boolean test(Integer integer) throws Exception {
return integer > 8;
}
}).subscribe(new Consumer() {
@Override
public void accept(Integer integer) throws Exception {
System.out.println("next :" + integer);
}
});
}
//distinct过滤掉重复的数据项
public static void distinctOperator() {
Observable.just("A","A","B")
.distinct()
.subscribe(new Consumer() {
@Override
public void accept(String integer) throws Exception {
System.out.println("next :" + integer);
}
});
}
//ignoreElements 不发射任何数据
public static void ignoreElements() {
Observable.just(1,2,3,4,5)
.ignoreElements()
.subscribe(new Action() {
@Override
public void run() throws Exception {
System.out.println("完成了任务");
}
});
}
//elementAt 只发射第n项数据
public static void elementAtOperator() {
Observable.just(1,2,3,4,5,6,7)
.elementAt(2)
// .elementAt(12,34)
.subscribe(new Consumer() {
@Override
public void accept(Integer integer) throws Exception {
System.out.println("next:" + integer);
}
});
}
//window操作符
public static void windowOperator() {
Observable.range(1,10)
.window(2)
.subscribe(new Consumer>() {
@Override
public void accept(Observable integerObservable) throws Exception {
System.out.println("On next:" );
integerObservable.subscribe(new Consumer() {
@Override
public void accept(Integer integer) throws Exception {
System.out.println("accept:" + integer );
}
});
}
});
}
}