java.lang.Exception: TestIterator.init() must return an Iterable of arrays. at org.junit.runners.Parameterized.parametersMethodReturnedWrongType(Parameterized.java:343) at org.junit.runners.Parameterized.createRunnersForParameters(Parameterized.java:326) at org.junit.runners.Parameterized.<init>(Parameterized.java:282) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:29) at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:21) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:26) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.<init>(JUnit4TestReference.java:33) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestClassReference.<init>(JUnit4TestClassReference.java:25) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.createTest(JUnit4TestLoader.java:48) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestLoader.loadTests(JUnit4TestLoader.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Error Cause：
使用@Parameters修饰的方法，返回值应该为Collection<T[]>
如果使用return Arrays.asList(parameters);则parameters应该为二维数组。
第一维描述参数组数，即有测试多少次
第二维描述参数个数，即执行一次测试，需要向构造函数传递多少个参数
source code:
org.junit.runners.Parameterized.java:
private void createRunnersForParameters(Iterable<Object[]> allParameters, String namePattern) throws InitializationError, Exception { try { int i = 0; for (Object[] parametersOfSingleTest : allParameters) { String name = nameFor(namePattern, i, parametersOfSingleTest); TestClassRunnerForParameters runner = new TestClassRunnerForParameters( getTestClass().getJavaClass(), parametersOfSingleTest, name); runners.add(runner); ++i; } } catch (ClassCastException e) { throw parametersMethodReturnedWrongType(); } }
