运行简单的 Neo4J 测试时出现 NoClassDefFoundError com/google/inject/Injector

Question

我正在尝试启动并运行编写嵌入式 Neo4J Java 1.8 应用程序。我正在遵循开发人员手册并尝试运行一个简单的测试来初始化本地测试数据库：

 @Test
 public void initNeo4J() {
     graphDb = new TestGraphDatabaseFactory().newImpermanentDatabase();
 }

我看到一个运行时异常，其根本原因是：

 Caused by: java.lang.NoClassDefFoundError: com/google/inject/Injector

如果我将 Google Guice 添加到类路径中，此错误就会消失并且一切正常。但是，我没有在任何地方看到这种依赖关系，所以我觉得我错过了什么或做错了什么。这只是一个未记录的依赖项还是我错过了一个将注入器引入的关键依赖项？这是我当前的依赖项：

 <dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j</artifactId>
    <version>3.0.0</version>
 </dependency>
 <dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-kernel</artifactId>
    <version>3.0.0</version>
    <scope>test</scope>
    <type>test-jar</type>
 </dependency>
 <dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-io</artifactId>
    <version>3.0.0</version>
    <scope>test</scope>
    <type>test-jar</type>
 </dependency>

编辑，这是完整的堆栈跟踪：

java.lang.RuntimeException: Error starting org.neo4j.test.TestGraphDatabaseFactory$1$1, C:\project\socialalpha\socialalpha-spark\neo4j-dev\target\test-data\impermanent-db
    at org.neo4j.kernel.impl.factory.GraphDatabaseFacadeFactory.newFacade(GraphDatabaseFacadeFactory.java:144)
    at org.neo4j.kernel.impl.factory.CommunityFacadeFactory.newFacade(CommunityFacadeFactory.java:40)
    at org.neo4j.kernel.impl.factory.GraphDatabaseFacadeFactory.newFacade(GraphDatabaseFacadeFactory.java:108)
    at org.neo4j.test.TestGraphDatabaseFactory$1.newDatabase(TestGraphDatabaseFactory.java:232)
    at org.neo4j.graphdb.factory.GraphDatabaseBuilder.newGraphDatabase(GraphDatabaseBuilder.java:183)
    at org.neo4j.test.TestGraphDatabaseFactory.newImpermanentDatabase(TestGraphDatabaseFactory.java:60)
    at com.sa.TestNeo4J.initNeo4J(TestNeo4J.java:43)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:86)
    at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:514)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:215)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:142)
    at org.testng.internal.Invoker.invokeBeforeGroupsConfigurations(Invoker.java:857)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:581)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:820)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1128)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:129)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:112)
    at org.testng.TestRunner.privateRun(TestRunner.java:782)
    at org.testng.TestRunner.run(TestRunner.java:632)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:366)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:361)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:319)
    at org.testng.SuiteRunner.run(SuiteRunner.java:268)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1244)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1169)
    at org.testng.TestNG.run(TestNG.java:1064)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:126)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:137)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:58)
Caused by: org.neo4j.kernel.lifecycle.LifecycleException: Component 'org.neo4j.kernel.impl.util.Neo4jJobScheduler@5629510' failed to initialize. Please see attached cause exception.
    at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.init(LifeSupport.java:416)
    at org.neo4j.kernel.lifecycle.LifeSupport.init(LifeSupport.java:62)
    at org.neo4j.kernel.lifecycle.LifeSupport.start(LifeSupport.java:98)
    at org.neo4j.kernel.impl.factory.GraphDatabaseFacadeFactory.newFacade(GraphDatabaseFacadeFactory.java:140)
    ... 34 more
Caused by: java.lang.NoClassDefFoundError: com/google/inject/Injector
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.getDeclaredMethod(Class.java:2128)
    at org.neo4j.kernel.impl.util.DebugUtil.trackTest(DebugUtil.java:300)
    at org.neo4j.kernel.impl.util.Neo4jJobScheduler.init(Neo4jJobScheduler.java:46)
    at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.init(LifeSupport.java:406)
    ... 37 more
Caused by: java.lang.ClassNotFoundException: com.google.inject.Injector
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 43 more

Answer 1

这是 Neo4j 中的一个错误。

暂时可以添加Guice：

<dependency>
    <groupId>com.google.inject</groupId>
    <artifactId>guice</artifactId>
    <version>4.2.0</version>
</dependency>

官方修复即将到来，您可以关注问题 #10722。

更多信息：https : //github.com/neo4j/neo4j/issues/10722#issuecomment-374417890

Answer 2

最终我意识到这是由于类路径上的其他冲突造成的，很可能是旧/新版本的 Google Guava。