RxJava/RxAndroid：ReplaySubject

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import io.reactivex.observers.DisposableObserver;
import io.reactivex.subjects.ReplaySubject;

public class MainActivity extends AppCompatActivity {
    private String TAG = "输出";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ReplaySubject mReplaySubject = ReplaySubject.create(128);
        mReplaySubject.subscribe(mDisposableObserver1);
        mReplaySubject.onNext(0);
        mReplaySubject.onNext(1);
        mReplaySubject.onNext(2);

        mReplaySubject.subscribe(mDisposableObserver2);
    }

    private DisposableObserver mDisposableObserver1 = new DisposableObserver<Integer>() {
        @Override
        public void onNext(Integer i) {
            Log.d(TAG, "onNext-1:" + i);
        }

        @Override
        public void onComplete() {
            Log.d(TAG, "onComplete-1");
        }

        @Override
        public void onError(Throwable e) {
            Log.e(TAG, e.toString(), e);
        }
    };

    private DisposableObserver mDisposableObserver2 = new DisposableObserver<Integer>() {

        @Override
        public void onNext(Integer integer) {
            Log.d(TAG, "onNext-2:" + integer);
        }

        @Override
        public void onError(Throwable e) {

        }

        @Override
        public void onComplete() {
            Log.d(TAG, "onComplete-2");
        }
    };
}

output:

01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-1:0
01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-1:1
01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-1:2
01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-2:0
01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-2:1
01-23 17:16:15.802 5165-5165/zhangphil.book D/输出: onNext-2:2