[RxJava^Android]项目经验分享 --- 失败重试-白红宇

[RxJava^Android]项目经验分享 --- 失败重试

阅读量：4665 次

发布时间：2019-06-09

本文共 6033 字，大约阅读时间需要 20 分钟。

简单介绍一下业务逻辑：获取字符串，如果获取失败进行10次重试，超出10次未成功视为失败。

模拟获取字符串场景

代码块

class MsgTool {        int count;        String getMsg() throws Exception {            count++;            LogUtils.d("execute getMsg count : " + count);            if (count == 15) {                return "getMsg";            } else {                throw new Exception("exception getMsg");            }        }    }

Java代码实现逻辑（实现方式很多种，这里不是重点）

代码块

public void testMain() {        LogUtils.d("result : " + getSyncMsg());    }    private String getSyncMsg() {        MsgTool msgTool = new MsgTool();        String result = null;        boolean isSuccess = false;        int count = 0;        while ((count < 10) && !isSuccess) {            try {                result = msgTool.getMsg();                isSuccess = true;            } catch (Exception e) {                count++;            }        }        return result;    }

输出结果

23:33:14.908 32364-32377/? D/LogUtils: execute getMsg count : 123:33:14.908 32364-32377/? D/LogUtils: execute getMsg count : 223:33:14.908 32364-32377/? D/LogUtils: execute getMsg count : 323:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 423:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 523:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 623:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 723:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 823:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 923:33:14.909 32364-32377/? D/LogUtils: execute getMsg count : 1023:33:14.909 32364-32377/? D/LogUtils: result : null

针对上述业务逻辑改为RxJava实现，使用操作符retry可实现

代码块

public void testMain() {        getSyncMsg().subscribe(getSubscriber());    }    private Observable
    
      getSyncMsg() {        MsgTool msgTool = new MsgTool();        Observable
     
       o = Observable.create(subscriber -> {            try {                subscriber.onNext(msgTool.getMsg());                subscriber.onCompleted();            } catch (Exception e) {                subscriber.onError(e);            }        });        return o.retry(10);    }        private Subscriber

输出结果

23:45:43.761 3285-3307/? D/LogUtils: execute getMsg count : 123:45:43.762 3285-3307/? D/LogUtils: execute getMsg count : 223:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 323:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 423:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 523:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 623:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 723:45:43.763 3285-3307/? D/LogUtils: execute getMsg count : 823:45:43.764 3285-3307/? D/LogUtils: execute getMsg count : 923:45:43.764 3285-3307/? D/LogUtils: execute getMsg count : 1023:45:43.764 3285-3307/? D/LogUtils: execute getMsg count : 1123:45:43.765 3285-3307/? D/LogUtils: onError : java.lang.Exception: exception getMsg

下面我们增加一个业务逻辑，每次重试延迟一秒种。此功能不做Java代码实现（使用定时器、Android系统下使用Handler等），而用RxJava代码实现，虽然看着很迷糊，但是慢慢品味就会发觉它的魅力所在。

public void testMain() {        getSyncMsg().subscribe(getSubscriber());    }    private Observable
    
      getSyncMsg() {        MsgTool msg = new MsgTool();        Observable
     
       o = Observable.create(subscriber -> {            try {                subscriber.onNext(msg.getMsg());                subscriber.onCompleted();            } catch (Exception e) {                subscriber.onError(e);            }        });        return o.retryWhen(this::delayRetry);    }     //此方法就是魅力的所在    private Observable

输出结果

00:36:57.271 19355-19372/? D/LogUtils: onStart00:36:57.297 19355-19372/? D/LogUtils: execute getMsg count : 100:36:58.305 19355-19377/? D/LogUtils: execute getMsg count : 200:36:59.306 19355-19404/? D/LogUtils: execute getMsg count : 300:37:00.307 19355-19375/? D/LogUtils: execute getMsg count : 400:37:01.308 19355-19376/? D/LogUtils: execute getMsg count : 500:37:02.308 19355-19377/? D/LogUtils: execute getMsg count : 600:37:03.309 19355-19404/? D/LogUtils: execute getMsg count : 700:37:04.309 19355-19375/? D/LogUtils: execute getMsg count : 800:37:05.310 19355-19376/? D/LogUtils: execute getMsg count : 900:37:06.311 19355-19377/? D/LogUtils: execute getMsg count : 1000:37:06.320 19355-19377/? D/LogUtils: onError : java.lang.Exception: exception getMsg

转载于:https://www.cnblogs.com/assassin-l/p/5088963.html

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