RxJava2.0 学习（2）----实际使用场景 2019年
看了 nanchen 大神得 Rxjava2.0 demo 自己做下总结
demo地址
https://github.com/nanchen2251/RxJava2Examples
0 线程切换
subscribeOn() 指定的就是发射事件的线程,多次调用 subscribeOn() 只有第一次的有效
observerOn 指定的就是订阅者接收事件的线程,但多次指定订阅者接收线程是可以的，也就是说每调用一次 observerOn()，下游的线程就会切换一次
Observable.create(new ObservableOnSubscribe<Integer>() {
@Override
public void subscribe(@NonNull ObservableEmitter<Integer> e) throws Exception {
Log.e(TAG, "Observable thread is : " + Thread.currentThread().getName());
e.onNext(1);
e.onComplete();
}
}).subscribeOn(Schedulers.newThread())
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.doOnNext(new Consumer<Integer>() {
@Override
public void accept(@NonNull Integer integer) throws Exception {
Log.e(TAG, "After observeOn(mainThread)，Current thread is " + Thread.currentThread().getName());
}
})
.observeOn(Schedulers.io())
.subscribe(new Consumer<Integer>() {
@Override
public void accept(@NonNull Integer integer) throws Exception {
Log.e(TAG, "After observeOn(io)，Current thread is " + Thread.currentThread().getName());
}
});
1 使用 Map 做简单的网络请求
执行顺序是 Map --> doOnNext --> subscribe (订阅者)
ps：doOnNext 在 订阅者收到消息之前 做点什么
Observable.create(new ObservableOnSubscribe<Response>() {
@Override
public void subscribe(@NonNull ObservableEmitter<Response> e) throws Exception {
Builder builder = new Builder()
.url("http://api.avatardata.cn/MobilePlace/LookUp?key=ec47b85086be4dc8b5d941f5abd37a4e&mobileNumber=13021671512")
.get();
Request request = builder.build();
Call call = new OkHttpClient().newCall(request);
Response response = call.execute();
e.onNext(response);
}
})
.subscribeOn(Schedulers.io())
.map(new Function<Response, MobileAddress>() {
@Override
public MobileAddress apply(@NonNull Response response) throws Exception {
Log.e(TAG, "map 线程:" + Thread.currentThread().getName() + "\n");
if (response.isSuccessful()) {
ResponseBody body = response.body();
if (body != null) {
Log.e(TAG, "map:转换前:" + response.body());
return new Gson().fromJson(body.string(), MobileAddress.class);
}
}
return null;
}
}).observeOn(AndroidSchedulers.mainThread())
.doOnNext(new Consumer<MobileAddress>() {
@Override
public void accept(@NonNull MobileAddress s) throws Exception {
Log.e(TAG, "doOnNext 线程:" + Thread.currentThread().getName() + "\n");
mRxOperatorsText.append("\ndoOnNext 线程:" + Thread.currentThread().getName() + "\n");
Log.e(TAG, "doOnNext: 保存成功：" + s.getResult().toString() + "\n");
mRxOperatorsText.append("doOnNext: 保存成功：" + s.getResult().toString() + "\n");
}
})
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<MobileAddress>() {
@Override
public void accept(@NonNull MobileAddress data) throws Exception {
Log.e(TAG, "subscribe 线程:" + Thread.currentThread().getName() + "\n");
mRxOperatorsText.append("\nsubscribe 线程:" + Thread.currentThread().getName() + "\n");
Log.e(TAG, "成功:" + data.toString() + "\n");
mRxOperatorsText.append("成功:" + data.toString() + "\n");
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
Log.e(TAG, "subscribe 线程:" + Thread.currentThread().getName() + "\n");
mRxOperatorsText.append("\nsubscribe 线程:" + Thread.currentThread().getName() + "\n");
Log.e(TAG, "失败：" + throwable.getMessage() + "\n");
mRxOperatorsText.append("失败：" + throwable.getMessage() + "\n");
}
});
2 使用Rx2-Networking
Rx2AndroidNetworking 使用此框架 进行网络请求。
getObjectObservable(MobileAddress.class) 方便了 实体类结构。
Rx2AndroidNetworking.get("http://api.avatardata.cn/MobilePlace/LookUp?key=ec47b85086be4dc8b5d941f5abd37a4e&mobileNumber=13021671512")
.build()
.getObjectObservable(MobileAddress.class)
.observeOn(AndroidSchedulers.mainThread()) // 为doOnNext() 指定在主线程，否则报错
.doOnNext(new Consumer<MobileAddress>() {
@Override
public void accept(@NonNull MobileAddress data) throws Exception {
Log.e(TAG, "doOnNext:"+Thread.currentThread().getName()+"\n" );
mRxOperatorsText.append("\ndoOnNext:"+Thread.currentThread().getName()+"\n" );
Log.e(TAG,"doOnNext:"+data.toString()+"\n");
mRxOperatorsText.append("doOnNext:"+data.toString()+"\n");
}
})
.map(new Function<MobileAddress, ResultBean>() {
@Override
public ResultBean apply(@NonNull MobileAddress mobileAddress) throws Exception {
Log.e(TAG, "\n" );
mRxOperatorsText.append("\n");
Log.e(TAG, "map:"+Thread.currentThread().getName()+"\n" );
mRxOperatorsText.append("map:"+Thread.currentThread().getName()+"\n" );
return mobileAddress.getResult();
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<ResultBean>() {
@Override
public void accept(@NonNull ResultBean data) throws Exception {
Log.e(TAG, "subscribe 成功:"+Thread.currentThread().getName()+"\n" );
mRxOperatorsText.append("\nsubscribe 成功:"+Thread.currentThread().getName()+"\n" );
Log.e(TAG, "成功:" + data.toString() + "\n");
mRxOperatorsText.append("成功:" + data.toString() + "\n");
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
Log.e(TAG, "subscribe 失败:"+Thread.currentThread().getName()+"\n" );
mRxOperatorsText.append("\nsubscribe 失败:"+Thread.currentThread().getName()+"\n" );
Log.e(TAG, "失败："+ throwable.getMessage()+"\n" );
mRxOperatorsText.append("失败："+ throwable.getMessage()+"\n");
}
});
使用ZIP 结合多个接口的数据再更新ui
将observable1 和 observable2同时请求 处理合并后叫给订阅者
其中有一个请求异常就视为【失败】
Observable<MobileAddress> observable1 = Rx2AndroidNetworking.get("http://api.avatardata.cn/MobilePlace/LookUp?key=ec47b85086be4dc8b5d941f5abd37a4e&mobileNumber=13021671512")
.build()
.getObjectObservable(MobileAddress.class);
Observable<CategoryResult> observable2 = Network.getGankApi()
.getCategoryData("Android",1,1);
Observable.zip(observable1, observable1, new BiFunction<MobileAddress, CategoryResult, String>() {
@Override
public String apply(@NonNull MobileAddress mobileAddress, @NonNull CategoryResult categoryResult) throws Exception {
return "合并后的数据为：手机归属地："+mobileAddress.getResult().getMobilearea()+"人名："+categoryResult.results.get(0).who;
}
}).subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<String>() {
@Override
public void accept(@NonNull String s) throws Exception {
Log.e(TAG, "accept: 成功：" + s+"\n");
mRxOperatorsText.setText(s);
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
mRxOperatorsText.setText("失败");
Log.e(TAG, "accept: 失败：" + throwable+"\n");
}
});
使用 flatmap （连续请求）
（多个网络请求依次依赖，比如：
1、注册用户前先通过接口A获取当前用户是否已注册，再通过接口B注册;
2、注册后自动登录，先通过注册接口注册用户信息，注册成功后马上调用登录接口进行自动登录。
例子所用API来自天狗网）
Rx2AndroidNetworking.get("http://www.tngou.net/api/food/list")
.addQueryParameter("rows", 1 + "")
.build()
.getObjectObservable(FoodList.class) // 发起获取食品列表的请求，并解析到FootList
.subscribeOn(Schedulers.io()) // 在io线程进行网络请求
.observeOn(AndroidSchedulers.mainThread()) // 在主线程处理获取食品列表的请求结果
.doOnNext(new Consumer<FoodList>() {
@Override
public void accept(@NonNull FoodList foodList) throws Exception {
// 先根据获取食品列表的响应结果做一些操作
Log.e(TAG, "accept: doOnNext :" + foodList.toString());
mRxOperatorsText.append("accept: doOnNext :" + foodList.toString()+"\n");
}
})
.observeOn(Schedulers.io()) // 回到 io 线程去处理获取食品详情的请求
.flatMap(new Function<FoodList, ObservableSource<FoodDetail>>() {
@Override
public ObservableSource<FoodDetail> apply(@NonNull FoodList foodList) throws Exception {
if (foodList != null && foodList.getTngou() != null && foodList.getTngou().size() > 0) {
return Rx2AndroidNetworking.post("http://www.tngou.net/api/food/show")
.addBodyParameter("id", foodList.getTngou().get(0).getId() + "")
.build()
.getObjectObservable(FoodDetail.class);
}
return null;
}
})
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<FoodDetail>() {
@Override
public void accept(@NonNull FoodDetail foodDetail) throws Exception {
Log.e(TAG, "accept: success ：" + foodDetail.toString());
mRxOperatorsText.append("accept: success ：" + foodDetail.toString()+"\n");
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
Log.e(TAG, "accept: error :" + throwable.getMessage());
mRxOperatorsText.append("accept: error :" + throwable.getMessage()+"\n");
}
});
使用 concat （进行缓存数据 和 网络新数据 处理）
使用场景：让用户回到 加载过的页面时有想刷新数据，不那么突然。
（先读取缓存数据并展示UI再获取网络数据刷新UI）
isFromNet 用来标记是否有本地数据
e.onNext(data); 看情况是否需要下一步
e.onComplete(); 没缓存的话 进入下一个请求
Observable<FoodList> cache = Observable.create(new ObservableOnSubscribe<FoodList>() {
@Override
public void subscribe(@NonNull ObservableEmitter<FoodList> e) throws Exception {
Log.e(TAG, "create当前线程:"+Thread.currentThread().getName() );
FoodList data = CacheManager.getInstance().getFoodListData();
// 在操作符 concat 中，只有调用 onComplete 之后才会执行下一个 Observable
if (data != null){ // 如果缓存数据不为空，则直接读取缓存数据，而不读取网络数据
isFromNet = false;
Log.e(TAG, "\nsubscribe: 读取缓存数据:" );
runOnUiThread(new Runnable() {
@Override
public void run() {
mRxOperatorsText.append("\nsubscribe: 读取缓存数据:\n");
}
});
e.onNext(data);
}else {
isFromNet = true;
runOnUiThread(new Runnable() {
@Override
public void run() {
mRxOperatorsText.append("\nsubscribe: 读取网络数据:\n");
}
});
Log.e(TAG, "\nsubscribe: 读取网络数据:" );
e.onComplete();
}
}
});
Observable<FoodList> network = Rx2AndroidNetworking.get("http://www.tngou.net/api/food/list")
.addQueryParameter("rows",10+"")
.build()
.getObjectObservable(FoodList.class);
// 两个 Observable 的泛型应当保持一致
Observable.concat(cache,network)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<FoodList>() {
@Override
public void accept(@NonNull FoodList tngouBeen) throws Exception {
Log.e(TAG, "subscribe 成功:"+Thread.currentThread().getName() );
if (isFromNet){
mRxOperatorsText.append("accept : 网络获取数据设置缓存: \n");
Log.e(TAG, "accept : 网络获取数据设置缓存: \n"+tngouBeen.toString() );
CacheManager.getInstance().setFoodListData(tngouBeen);
}
mRxOperatorsText.append("accept: 读取数据成功:" + tngouBeen.toString()+"\n");
Log.e(TAG, "accept: 读取数据成功:" + tngouBeen.toString());
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
Log.e(TAG, "subscribe 失败:"+Thread.currentThread().getName() );
Log.e(TAG, "accept: 读取数据失败："+throwable.getMessage() );
mRxOperatorsText.append("accept: 读取数据失败："+throwable.getMessage()+"\n");
}
});
}
使用 debounce （）
RxView 使用了的 Rxbanding （不是重点）
.debounce(2,TimeUnit.SECONDS) 点击事件，在2秒内重复点击，及时重新算。2秒后触发。
RxView.clicks(mRxOperatorsBtn)
.debounce(2,TimeUnit.SECONDS) // 过滤掉发射频率小于2秒的发射事件
.subscribe(new Consumer<Object>() {
@Override
public void accept(@NonNull Object o) throws Exception {
clickBtn();
}
});
}
private void clickBtn() {
Rx2AndroidNetworking.get("http://120.77.35.147:8080/goods/homepage")
// .addQueryParameter("rows",2+"") // 只获取两条数据
.build()
.getObjectObservable(ShopMallFristBean.class)
.subscribeOn(Schedulers.io()) // 在 io 线程进行网络请求
.observeOn(AndroidSchedulers.mainThread()) // 在主线程进行更新UI等操作
.subscribe(new Consumer<ShopMallFristBean>() {
@Override
public void accept(@NonNull ShopMallFristBean foodList) throws Exception {
Log.e(TAG, "accept: 获取数据成功:"+foodList.toString()+"\n" );
mRxOperatorsText.append("accept: 获取数据成功:"+foodList.toString()+"\n" );
}
}, new Consumer<Throwable>() {
@Override
public void accept(@NonNull Throwable throwable) throws Exception {
Log.e(TAG, "accept: 获取数据失败："+throwable.getMessage() +"\n");
mRxOperatorsText.append("accept: 获取数据失败："+throwable.getMessage() +"\n");
}
});
使用 interval 实现心跳机制
Disposable 一次性资源；
interval(1, TimeUnit.SECONDS) 每个一秒发送一次事件
doOnNext 提前处理事件
mDisposable =
Flowable.interval(1, TimeUnit.SECONDS)
.doOnNext(new Consumer<Long>() {
@Override
public void accept(@NonNull Long aLong) throws Exception {
Log.e(TAG, "accept: doOnNext : "+aLong );
}
})
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<Long>() {
@Override
public void accept(@NonNull Long aLong) throws Exception {
Log.e(TAG, "accept: 设置文本 ："+aLong );
mRxOperatorsText.append("accept: 设置文本 ："+aLong +"\n");
}
});
学习后，掌握了基本的使用方法，但是还有一些细节上的问题，有疑惑。。。 等候面消化消化在来分享，欢迎评论交流~~
