使用 Robolectric : java. lang.InstantiationException 的 Android 库 JUnit 测试

Question

尝试使用 Robolectric 在 Android 库项目上运行 JUnit 测试时出现以下错误:

java.lang.RuntimeException: java.lang.InstantiationException
    at com.xtremelabs.robolectric.ApplicationResolver.newApplicationInstance(ApplicationResolver.java:56)
    at com.xtremelabs.robolectric.ApplicationResolver.resolveApplication(ApplicationResolver.java:36)
    at com.xtremelabs.robolectric.RobolectricTestRunner.createApplication(RobolectricTestRunner.java:246)
    at com.xtremelabs.robolectric.RobolectricTestRunner.setupApplicationState(RobolectricTestRunner.java:233)
    at com.xtremelabs.robolectric.RobolectricTestRunner.internalBeforeTest(RobolectricTestRunner.java:177)
    at com.xtremelabs.robolectric.RobolectricTestRunner.methodBlock(RobolectricTestRunner.java:157)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    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)
Caused by: java.lang.InstantiationException
    at sun.reflect.InstantiationExceptionConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at com.xtremelabs.robolectric.ApplicationResolver.newApplicationInstance(ApplicationResolver.java:54)
    ... 20 more

我的第一个想法是我在测试中犯了一个错误，所以我尽可能地简化了测试运行:

import static org.junit.Assert.*;

import org.junit.Test;
import org.junit.runner.RunWith;

import com.xtremelabs.robolectric.RobolectricTestRunner;

@RunWith(RobolectricTestRunner.class)
public class CommonDataTest {

    @Test
    public void test(){
        assertTrue(true);
    }

}

但我仍然得到同样的错误。我按照此处所述设置项目:http://robolectric.org/eclipse-quick-start/奇怪的是，它可以毫无问题地与其他 Android 库项目一起使用。

任何帮助将不胜感激!提前致谢!

Answer 1

Robolectric 似乎无法从我的库中创建应用程序，因此我更换了 TestRunner:

import org.junit.runners.model.InitializationError;

import android.app.Application;

import com.xtremelabs.robolectric.RobolectricTestRunner;

public class MyTestRunner extends RobolectricTestRunner {

    public MyTestRunner(Class<?> testClass)
            throws InitializationError {
        super(testClass);
    }

    @Override protected Application createApplication() {
        return new Application() {
        };
    }


}

并使用它代替 RobolectricTestRunner:

@RunWith(MyTestRunner.class)

测试现在运行正常。