RxBus在rxjava2.0 的使用

   今天自己刚好要写一个例子，本来想要用evenbus，但是想到自己用的是rxjava，在用evenbus就比较不和了吧! 所以就自己写了个rxbus

   1. 首先是gradle的配置

compile 'io.reactivex.rxjava2:rxjava:2.0.8'

compile 'io.reactivex.rxjava2:rxandroid:2.0.1'

compile 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'

compile 'com.jakewharton.rxrelay2:rxrelay:2.0.0'//出现异常也不会终止订阅关系 不使用第一个rxbus的写法的话，可以不需要这个

 2.RxBus的写法

 1. 在订阅者处理事件出现异常后，订阅者无法再收到事件，这是 RxJava 当初本身的设计原则，但是在事件总线中这反而是个问题，不过

 JakeWharton 大神写了即使出现异常也不会终止订阅关系的 RxRelay，所以基于 RxRelay 就能写出有异常处理能力的 Rxbus。

import com.jakewharton.rxrelay2.PublishRelay;
import com.jakewharton.rxrelay2.Relay;

import io.reactivex.Observable;

/**
 * 有异常处理的 Rxbus
 * Created by huxh on 2017/4/10.
 */

public class RxBus {
private static volatile RxBus instance;
    private final Relay<Object> mBus;

    public RxBus() {
this.mBus = PublishRelay.create().toSerialized();
    }

public static RxBus getDefault() {
if (instance == null) {
synchronized (RxBus.class) {
if (instance == null) {
instance = Holder.BUS;
                }
            }
        }
return instance;
    }
    public void post(Object obj) {
mBus.accept(obj);
    }

public <T> Observable<T> toObservable(Class<T> tClass) {
return  mBus.ofType(tClass);
    }

public Observable<Object> toObservable() {
return mBus;
    }

public boolean hasObservers() {
return mBus.hasObservers();
    }

private static class Holder {
private static final RxBus BUS = new RxBus();
    }

}
2.没有背压处理（Backpressure）的 Rxbus

import io.reactivex.Observable;
import io.reactivex.subjects.PublishSubject;
import io.reactivex.subjects.Subject;

public class RxBus {

private final Subject<Object> mBus;

private RxBus() {
// toSerialized method made bus thread safe
mBus = PublishSubject.create().toSerialized();
}

public static RxBus get() {
return Holder.BUS;
}

public void post(Object obj) {
mBus.onNext(obj);
}

public <T> Observable<T> toObservable(Class<T> tClass) {
return mBus.ofType(tClass);
}

public Observable<Object> toObservable() {
return mBus;
}

public boolean hasObservers() {
return mBus.hasObservers();
}

private static class Holder {
private static final RxBus BUS = new RxBus();
}
}

3.有背压处理的 RxBus

import io.reactivex.Flowable;
import io.reactivex.processors.FlowableProcessor;
import io.reactivex.processors.PublishProcessor;

public class RxBus {

private final FlowableProcessor<Object> mBus;

private RxBus() {
// toSerialized method made bus thread safe
mBus = PublishProcessor.create().toSerialized();
}

public static RxBus get() {
return Holder.BUS;
}

public void post(Object obj) {
mBus.onNext(obj);
}

public <T> Flowable<T> toFlowable(Class<T> tClass) {
return mBus.ofType(tClass);
}

public Flowable<Object> toFlowable() {
return mBus;
}

public boolean hasSubscribers() {
return mBus.hasSubscribers();
}

private static class Holder {
private static final RxBus BUS = new RxBus();
}
}

有些朋友不知道有背压与没有背压是什么意识，可以参考 http://flyou.ren/2017/04/05/关于RxJava背压/讲的很详细

好了，到了如何使用rxbus了，其实很简单

比如A跳转到B ，我这边是recycleview 的item点击跳转，传一个对象

   @Override
        public void onItemClick(View view, int position) {
            ActicleBean.OthersBean bean = mDataList.get(position);
            RxBus.getDefault().post(bean);
            startActivity(new Intent(ArticleActivity.this,ActicleListActivity.class));
        }

在B类上 直接写就可以获得了你所需要传的对象

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

import com.frame.huxh.mvpdemo.R;
import com.frame.huxh.mvpdemo.bean.ActicleBean;
import com.frame.huxh.mvpdemo.rxbus.RxBus;
import com.frame.huxh.mvpdemo.utils.ToastUtils;

import io.reactivex.annotations.NonNull;
import io.reactivex.functions.Consumer;
import io.reactivex.functions.Function;

public class ActicleListActivity extends AppCompatActivity {

@Override
    protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_acticle_list);
        operateBus();
    }

/**
 * RxBus
 */
 private void operateBus() {
        RxBus.getDefault().toObservable()
                .map(new Function<Object, ActicleBean.OthersBean>() {
@Override
                    public ActicleBean.OthersBean apply(@NonNull Object o) throws Exception {
return (ActicleBean.OthersBean) o;
                    }

                })
                .subscribe(new Consumer<ActicleBean.OthersBean>() {
@Override
                    public void accept(@NonNull ActicleBean.OthersBean othersBean) throws Exception {
if (othersBean != null) {
                            ToastUtils.toast(ActicleListActivity.this, "othersBean" + othersBean.getDescription());
                        }
                    }

                });
    }
}