一、背景
在做自動(dòng)化測(cè)試中，經(jīng)常會(huì)出現(xiàn)一些由于各種因素引起的假性失敗(非bug)，例如：頁(yè)面未加載出來(lái)、打開(kāi)app失敗等現(xiàn)象。每次檢查測(cè)試結(jié)果，需要花一些時(shí)間去鑒別是否為bug，采用的方法是再運(yùn)行一遍，于是：是否可以在case執(zhí)行失敗時(shí)自動(dòng)rerun？

二、實(shí)現(xiàn)Rule
Junit4 提供了一些高級(jí)特性，如@Rule，框架自帶了一些Rule，也可以自己定義。以下自定義一個(gè)Rule，實(shí)現(xiàn)失敗重跑機(jī)制：
//使用自定義Rule
@Rule
public RetryRule retryRule = new RetryRule(2);

//實(shí)現(xiàn)TestRule接口
public class RetryRule implements TestRule {
private int retryCount;

    public RetryRule(int retryCount) {
        this.retryCount = retryCount;
    }

    public void setRetryCount(int retryCount) {
        this.retryCount = retryCount;
    }

    public Statement apply(Statement base, Description description) {
        return statement(base, description);
    }

    private Statement statement(final Statement base, final Description description) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {
                Throwable caughtThrowable = null;
                // implement retry logic here
                for (int i = 0; i < retryCount; i++) {
                    try {
                        base.evaluate();
                        HFLog.logMessage("-----------RetryRunner-----------: Test case success, " + (i + 1));
                        return;
                    } catch (Throwable t) {
                        caughtThrowable = t;
                        HFLog.logMessage("-----------RetryRunner-----------: Test case failed, " + (i + 1) + ", " + getExceptionMsg(caughtThrowable));
                    }
                }
                throw caughtThrowable;
            }
        };
    }

三、參考資料：
https://segmentfault.com/a/1190000005923632
https://tonydeng.github.io/2016/05/11/junit-more-feature/
http://haibin369.iteye.com/blog/2088541