通過提供一種，觀察者和訂閱者的模式，的架構(gòu)，來優(yōu)化邏輯流程。適用于復(fù)雜和需要多數(shù)據(jù)轉(zhuǎn)換和長流程。
定義三個對象類
public class ResultInfo { public int code; public String msg; public String data; } public class UserInfo { public int status; public String name; public String head; public List<SkillInfo> skillInfoList; } public class SkillInfo { public String name; public int level; public SkillInfo(String name, int level){ this.name = name; this.level = level; } }
一段邏輯測試代碼：
private ResultInfo login_http(String name, String pwd){ ResultInfo resultInfo = new ResultInfo(); resultInfo.code = 0; resultInfo.msg = ""; Gson gson = new Gson(); UserInfo userInfo = new UserInfo(); userInfo.status = 1; userInfo.name = ""; userInfo.head = ""; userInfo.skillInfoList = new ArrayList<>(); userInfo.skillInfoList.add(new SkillInfo("音樂", 10)); userInfo.skillInfoList.add(new SkillInfo("美術(shù)", 6)); userInfo.skillInfoList.add(new SkillInfo("體育", 9)); resultInfo.data = gson.toJson(userInfo); return resultInfo; }
版本1：（定義一個被觀察的對象，和訂閱者，設(shè)置他們使用的線程，最后通過調(diào)用 subscribe，使他們關(guān)聯(lián)起來。且執(zhí)行）
Observable<ResultInfo> observable = Observable.create(new ObservableOnSubscribe<ResultInfo>() { @Override public void subscribe(ObservableEmitter<ResultInfo> e) throws Exception { e.onNext(login_http(name, pwd)); } }); Consumer<ResultInfo> consumer = new Consumer<ResultInfo>() { @Override public void accept(ResultInfo resultInfo) throws Exception { if(resultInfo.code == 0){ Gson gson = new Gson(); UserInfo userInfo = gson.fromJson(resultInfo.data, UserInfo.class); if(userInfo.status == 0){ // 注冊 Toast.makeText(getBaseContext(), "注冊", Toast.LENGTH_LONG).show(); } else if(userInfo.status == 1){ // 登錄 Toast.makeText(getBaseContext(), "登錄", Toast.LENGTH_LONG).show(); } } } }; // subscribeOn() 指定的是發(fā)送事件的線程, observeOn() 指定的是接收事件的線程. observable.subscribeOn(Schedulers.newThread()) .observeOn(AndroidSchedulers.mainThread()) .subscribe(consumer);
版本2：（在版本1的基礎(chǔ)上，通過在被觀察者調(diào)用map處理，觀察的數(shù)據(jù)，使數(shù)據(jù)只返回結(jié)果，而訂閱者也是對結(jié)果進行判斷，這里使用的數(shù)據(jù)類型發(fā)生了改變）。
Observable<Integer> observable = Observable.create(new ObservableOnSubscribe<ResultInfo>() { @Override public void subscribe(ObservableEmitter<ResultInfo> e) throws Exception { e.onNext(login_http(name, pwd)); } }).map(new Function<ResultInfo, Integer>() { @Override public Integer apply(ResultInfo resultInfo) throws Exception { return resultInfo.code; } }); Consumer<Integer> consumer = new Consumer<Integer>() { @Override public void accept(Integer code) throws Exception { if(code == 0){ Toast.makeText(getBaseContext(), "成功", Toast.LENGTH_LONG).show(); } else{ Toast.makeText(getBaseContext(), "失敗", Toast.LENGTH_LONG).show(); } } }; // subscribeOn() 指定的是發(fā)送事件的線程, observeOn() 指定的是接收事件的線程. observable.subscribeOn(Schedulers.newThread()) .observeOn(AndroidSchedulers.mainThread()) .subscribe(consumer);
版本3：（使用RxJava的優(yōu)勢，鏈式調(diào)用，來完成邏輯）
Observable.create(new ObservableOnSubscribe<ResultInfo>() { @Override public void subscribe(ObservableEmitter<ResultInfo> e) throws Exception { e.onNext(login_http(name, pwd)); } }).map(new Function<ResultInfo, Integer>() { @Override public Integer apply(ResultInfo resultInfo) throws Exception { return resultInfo.code; } }).subscribeOn(Schedulers.newThread()) .observeOn(AndroidSchedulers.mainThread()) .subscribe(new Consumer<Integer>() { @Override public void accept(Integer code) throws Exception { if(code == 0){ Toast.makeText(getBaseContext(), "成功", Toast.LENGTH_LONG).show(); } else{ Toast.makeText(getBaseContext(), "失敗", Toast.LENGTH_LONG).show(); } } });
版本4：（同時引入了flatMap來，處理集合數(shù)據(jù)，返回集合，每個數(shù)據(jù)都可以響應(yīng)訂閱者的accept方法，同時引入了filter對數(shù)據(jù)進行過濾，類似于C#中的，linq用法。）
Observable.create(new ObservableOnSubscribe<ResultInfo>() { @Override public void subscribe(ObservableEmitter<ResultInfo> e) throws Exception { e.onNext(login_http(name, pwd)); } }).map(new Function<ResultInfo, UserInfo>() { @Override public UserInfo apply(ResultInfo resultInfo) throws Exception { UserInfo userInfo = new Gson().fromJson(resultInfo.data, UserInfo.class); return userInfo; } }).flatMap(new Function<UserInfo, Observable<SkillInfo>>() { @Override public Observable<SkillInfo> apply(UserInfo userInfo) throws Exception { return Observable.fromArray(userInfo.skillInfoList.toArray(new SkillInfo[userInfo.skillInfoList.size()])); } }).filter(new Predicate<SkillInfo>() { @Override public boolean test(SkillInfo skillInfo) throws Exception { return skillInfo.level > 8; } }) .subscribeOn(Schedulers.newThread()) .observeOn(AndroidSchedulers.mainThread()) .subscribe(new Consumer<SkillInfo>() { @Override public void accept(SkillInfo skillInfo) throws Exception { Toast.makeText(getBaseContext(), skillInfo.name + " " + skillInfo.level, Toast.LENGTH_SHORT).show(); } }); // 類似于linq , take, skip deng
版本5：當然，RxJava的用法不僅僅這些，還有沒有提到的，take，取幾個成員，skip,跳過幾個成員。等，這些用法和C#中的linq類似，詳細很好理解
// 代碼，略
// 源碼解讀，后面再補上。
implementation "io.reactivex.rxjava2:rxjava:2.0.7"
implementation "io.reactivex.rxjava2:rxandroid:2.0.1"
