RxJava2 / RxAndroid2操作符ofType：根据类型选择输出结果

例如：

package zhangphil.app;

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

import io.reactivex.Observable;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.CompositeDisposable;
import io.reactivex.observers.DisposableObserver;
import io.reactivex.schedulers.Schedulers;

public class MainActivity extends AppCompatActivity {
    private final String TAG = getClass().getSimpleName();

    private CompositeDisposable mCompositeDisposable = new CompositeDisposable();

    private Object[] test_data = {
            1, "zhang", 2, 3, "phil", 5, 5, 6, 7, 7, 8, 9
    }; // 故意设置若干重复的数据，等待去重复数据

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        test();
    }

    private void test() {
        DisposableObserver disposableObserver = new DisposableObserver<Object>() {
            @Override
            public void onNext(Object o) {
                Log.d(TAG, "#####开始#####");
                Log.d("数据", String.valueOf(o));
                Log.d(TAG, "#####结束#####");
            }

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

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

        Observable<Object> observable = Observable.fromArray(test_data);

        mCompositeDisposable.add(observable
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .ofType(String.class) //只显示字符串类型
                .subscribeWith(disposableObserver));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        // 如果退出程序，就清除后台任务
        mCompositeDisposable.clear();
    }
}

输出：

05-18 10:28:43.170 14762-14762/zhangphil.app D/MainActivity: #####开始#####
05-18 10:28:43.170 14762-14762/zhangphil.app D/数据: zhang
05-18 10:28:43.170 14762-14762/zhangphil.app D/MainActivity: #####结束#####
05-18 10:28:43.170 14762-14762/zhangphil.app D/MainActivity: #####开始#####
05-18 10:28:43.170 14762-14762/zhangphil.app D/数据: phil
05-18 10:28:43.170 14762-14762/zhangphil.app D/MainActivity: #####结束#####
05-18 10:28:43.171 14762-14762/zhangphil.app D/MainActivity: onComplete

结果如预期，只输出字符串类型的数据。