android - 使用 Maven surefire 插件运行 Robolectric 测试时获取 ClassNotFoundException

Question

我已经使用 Android Maven 集成在 Eclipse 中建立了一个项目，并使用 Robolectric 进行了一些测试。

当我在 Eclipse 中部署测试时，测试运行良好。但是，当我尝试使用 Maven“安装”目标(这实际上是我在本地 Maven 存储库中需要的库)构建项目时，它在这些相同的测试中失败了。

日志显示以下错误:

testAll((package).MyTest)  Time elapsed: 0.006 sec  <<< ERROR!
java.lang.RuntimeException: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for (package).R
    at com.xtremelabs.robolectric.RobolectricTestRunner.createResourceLoader(RobolectricTestRunner.java:316)
    at com.xtremelabs.robolectric.RobolectricTestRunner.setupApplicationState(RobolectricTestRunner.java:270)
    at com.xtremelabs.robolectric.RobolectricTestRunner.internalBeforeTest(RobolectricTestRunner.java:221)
    at com.xtremelabs.robolectric.RobolectricTestRunner.methodBlock(RobolectricTestRunner.java:201)
    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.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:59)
    at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.executeTestSet(AbstractDirectoryTestSuite.java:120)
    at org.apache.maven.surefire.suite.AbstractDirectoryTestSuite.execute(AbstractDirectoryTestSuite.java:103)
    at org.apache.maven.surefire.Surefire.run(Surefire.java:169)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:350)
    at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)
Caused by: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for (package).R
    at javassist.Loader.findClass(Loader.java:359)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.findClass(RobolectricClassLoader.java:60)
    at javassist.Loader.loadClass(Loader.java:311)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.loadClass(RobolectricClassLoader.java:37)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at com.xtremelabs.robolectric.RobolectricTestRunner.createResourceLoader(RobolectricTestRunner.java:312)
    ... 22 more
Caused by: com.xtremelabs.robolectric.bytecode.IgnorableClassNotFoundException: msg because of javassist.NotFoundException: (package).R
    at com.xtremelabs.robolectric.bytecode.AndroidTranslator.onLoad(AndroidTranslator.java:80)
    at javassist.Loader.findClass(Loader.java:340)
    ... 29 more

其中 (package) 当然是我的主包的名称。这是我的 POM 的相关部分:

  <dependencies>
    <dependency>
      <groupId>com.google.android</groupId>
      <artifactId>android</artifactId>
      <version>2.1.2</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>com.pivotallabs</groupId>
        <artifactId>robolectric</artifactId>
        <version>0.9.8</version>
        <type>jar</type>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.hamcrest</groupId>
        <artifactId>hamcrest-core</artifactId>
        <version>1.2</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.8.2</version>
        <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
   <defaultGoal>package</defaultGoal>
    <plugins>
      <plugin>
        <groupId>com.jayway.maven.plugins.android.generation2</groupId>
        <artifactId>maven-android-plugin</artifactId>
        <version>2.8.3</version>
        <configuration>
        <genDirectory>${project.basedir}/gen</genDirectory>
          <androidManifestFile>${project.basedir}/AndroidManifest.xml</androidManifestFile>
          <assetsDirectory>${project.basedir}/assets</assetsDirectory>
          <resourceDirectory>${project.basedir}/res</resourceDirectory>
          <nativeLibrariesDirectory>${project.basedir}/src/main/native</nativeLibrariesDirectory>
          <sdk>
            <platform>7</platform>
          </sdk>
          <deleteConflictingFiles>true</deleteConflictingFiles>
          <undeployBeforeDeploy>true</undeployBeforeDeploy>
        </configuration>
        <extensions>true</extensions>
      </plugin>

      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.3.2</version>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
        </configuration>
      </plugin>

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.6</version>
        <configuration>
            <excludes>
                <exclude>**/Test*.java</exclude>
            </excludes>
        </configuration>
    </plugin>      
    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-javadoc-plugin</artifactId>
        <version>2.8</version>
    </plugin>
    </plugins>
  </build>

如您所见，我已尝试将“genDirectory”选项添加到 Maven Android 插件。但无济于事。

要让 surefire 插件“看到”R 类，我缺少什么？

还有一件事:我的代码实际上并未引用 R 类。

Answer 1

我也遇到了这个问题。

所以我仔细比较了 RobolectricSample 项目和我的项目。

令我惊讶的是，如果我没有先运行“mvn clean test”命令行，RobolectricSample 项目也无法工作。

于是我分析了差异，发现命令行也将“gen/xxx/R.java”编译成了“target/classes/xxx/R”。

这就是成功的诀窍，所以我执行了以下步骤:1.右键项目->Java Build；2. 将“{project}/gen”输出文件夹更改为“target/class”(而不是原来的“target/android-classes”)

就是这样，希望对您有所帮助。