how to zip in rxjava - multithreading

Question

Hi I'm a newbie with RXJava,I am trying to work on my first RxJava example that like below
Observable<String> myObservable = Observable.create(
new Observable.OnSubscribe<String>() {
public void call(Subscriber<? super String> subscriber) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
subscriber.onNext("hello world");
subscriber.onCompleted();
}
}
).subscribeOn(Schedulers.computation());
Observable<String> myObservable1 = Observable.just("thank you");
Observable observable3 = Observable.zip(myObservable, myObservable1, new Func2<String,String,String>() {
#Override
public String call(String o, String o2) {
return o+":"+o2;
}
});
observable3.subscribe(new Action1<String>() {
#Override
public void call(String o) {
System.out.println("before");
System.out.println(o);
}
});
System.out.println("after");
I want to print before then after,how I to do that with rxjava and without sleep

Answer 1

One possible way:
Observable<String> myObservable = Observable.create(
new Observable.OnSubscribe<String>() {
public void call(Subscriber<? super String> subscriber) {
subscriber.onNext("hello world");
subscriber.onCompleted();
}
}
).subscribeOn(Schedulers.computation());
Observable<String> myObservable1 = Observable.just("thank you");
Observable observable3 = Observable.zip(myObservable, myObservable1, new Func2<String,String,String>() {
#Override
public String call(String o, String o2) {
return o+":"+o2;
}
});
Observable.just("before").concatWith(observable3).concatWith(Observable.just("after")).toBlocking().subscribe(new Action1<String>() {
#Override
public void call(String s) {
System.out.println(s);
}
});
Result is:
before
hello world:thank you
after