junit4.12源碼分析-啟動到選擇runner

標籤：des   style   blog   color   io   os   ar   strong   for   

　　第一次寫原始碼分析，介紹運行流程和其中重要的類和介面！

　　JUnitCore

　　JUnitCore採用門面模式，可以啟動junit4，junit3測試，也可以測試指定class。JUnitCore聲明RunNotifier類，該類採用觀察者模式實現事件管理。RunListener為測試事件基類，有測試開始結束失敗等事件，如果想自訂事件可以繼承該類。預設增加了兩個RunListener，一個是TextListener，另一個是Result類函數createListener構造的Listener用於記錄開始結束時間、執行總數、失敗總數等。可看到run方法調用前觸發了fireTestRunStarted，執行後觸發了fireTestRunFinished。關鍵代碼（截取）

    private final RunNotifier notifier = new RunNotifier();    Result runMain(JUnitSystem system, String... args) {        RunListener listener = new TextListener(system);        addListener(listener);        return run(jUnitCommandLineParseResult.createRequest(defaultComputer()));    }    public Result run(Request request) {        return run(request.getRunner());    }    public Result run(Runner runner) {        Result result = new Result();        RunListener listener = result.createListener();        notifier.addFirstListener(listener);        try {            notifier.fireTestRunStarted(runner.getDescription());            runner.run(notifier);            notifier.fireTestRunFinished(result);        } finally {            removeListener(listener);        }        return result;    }

 

　　Request

　　對class和test的封裝，可以是一個class下所有test、所有class下所有test、還可以結合filter。classes方法擷取suite，suite裡包含各個類的runner。關鍵代碼（截取）

 

    public static Request classes(Computer computer, Class<?>... classes) {        try {            AllDefaultPossibilitiesBuilder builder = new AllDefaultPossibilitiesBuilder(true);            Runner suite = computer.getSuite(builder, classes);            return runner(suite);        } catch (InitializationError e) {            throw new RuntimeException(                    "Bug in saff‘s brain: Suite constructor, called as above, should always complete");        }    }

 

　　RunnerBuilder

　　建立runner採用builder模式，對於每一個class產生一個runner。

    private List<Runner> runners(Class<?>[] children) {        ArrayList<Runner> runners = new ArrayList<Runner>();        for (Class<?> each : children) {            Runner childRunner = safeRunnerForClass(each);            if (childRunner != null) {                runners.add(childRunner);            }        }        return runners;    }

　　AllDefaultPossibilitiesBuilder

　　選擇具體builder，預設為junit4Builder,如果class有@Ignore標註則為IgnoredBuilder，如果class有@RunWith標註則為IgnoredBuilder，如果測試方法有suite則為SuiteMethodBuilder，如果class繼承於junit.framework.TestCase則為JUnit38ClassRunner，否則預設時用JUnit4Builder返回BlockJUnit4ClassRunner

    public Runner runnerForClass(Class<?> testClass) throws Throwable {        List<RunnerBuilder> builders = Arrays.asList(                ignoredBuilder(),                annotatedBuilder(),                suiteMethodBuilder(),                junit3Builder(),                junit4Builder());        for (RunnerBuilder each : builders) {            Runner runner = each.safeRunnerForClass(testClass);            if (runner != null) {                return runner;            }        }        return null;    }

 

junit4.12源碼分析-啟動到選擇runner