如何使用JUNit測試Java-Spark？

Question

我不知道如何單元測試java的火花應用程序...

我在這裏有一個簡單的測試，但它與傑克遜異常失敗。我也試着設置主爲 「本地」

private JavaSparkContext sparkCtx; 

    @Before 
    public void init() throws IllegalArgumentException, IOException { 
     //ctxtBuilder = new ContextBuilder(tempFolder); 
     SparkConf conf = new SparkConf(); 
     conf.setMaster("local[2]"); 
     conf.setAppName("junit"); 
     sparkCtx = new JavaSparkContext(conf);  
    } 

    @Test 
    public void test() { 
     final List<Integer> nums = new ArrayList<Integer>(); 
     nums.add(3); 
     nums.add(4); 
     nums.add(2); 
     JavaRDD<Integer> rdd = sparkCtx.parallelize(nums,1); 
     assertEquals(3, rdd.count()); 

    } 

---

異常

java.lang.VerifyError: class com.fasterxml.jackson.module.scala.ser.ScalaIteratorSerializer overrides final method withResolved.(Lcom/fasterxml/jackson/databind/BeanProperty;Lcom/fasterxml/jackson/databind/jsontype/TypeSerializer;Lcom/fasterxml/jackson/databind/JsonSerializer;)Lcom/fasterxml/jackson/databind/ser/std/AsArraySerializerBase; 
    at java.lang.ClassLoader.defineClass1(Native Method) 
    at java.lang.ClassLoader.defineClass(ClassLoader.java:760) 
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) 
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) 
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73) 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:368) 
    at java.net.URLClassLoader$1.run(URLClassLoader.java:362) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.net.URLClassLoader.findClass(URLClassLoader.java:361) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) 
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) 
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) 
    at com.fasterxml.jackson.module.scala.ser.IteratorSerializerModule$class.$init$(IteratorSerializerModule.scala:70) 
    at com.fasterxml.jackson.module.scala.DefaultScalaModule.<init>(DefaultScalaModule.scala:19) 
    at com.fasterxml.jackson.module.scala.DefaultScalaModule$.<init>(DefaultScalaModule.scala:35) 
    at com.fasterxml.jackson.module.scala.DefaultScalaModule$.<clinit>(DefaultScalaModule.scala) 
    at org.apache.spark.rdd.RDDOperationScope$.<init>(RDDOperationScope.scala:78) 
    at org.apache.spark.rdd.RDDOperationScope$.<clinit>(RDDOperationScope.scala) 
    at org.apache.spark.SparkContext.withScope(SparkContext.scala:700) 
    at org.apache.spark.SparkContext.parallelize(SparkContext.scala:714) 
    at org.apache.spark.api.java.JavaSparkContext.parallelize(JavaSparkContext.scala:145) 
    at sal_mr.ingestion.storage.IngestionOutputFormatTest.test(IngestionOutputFormatTest.java:38) 
    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:497) 
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) 
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) 
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) 
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) 
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) 
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) 
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) 
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) 
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) 
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) 
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) 
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309) 
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) 
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) 

---

控制檯輸出：

2016-03-23 09:56:58 INFO SparkContext:59 - Running Spark version 1.5.0 
2016-03-23 09:56:59 INFO Utils:59 - Successfully started service 'sparkDriver' on port 38028. 
2016-03-23 09:57:00 INFO Utils:59 - Successfully started service 'SparkUI' on port 4040. 
2016-03-23 09:57:00 INFO Executor:59 - Starting executor ID driver on host localhost 
2016-03-23 09:57:00 INFO Utils:59 - Successfully started service 'org.apache.spark.network.netty.NettyBlockTransferService' on port 35071. 
2016-03-23 09:57:00 INFO BlockManagerMasterEndpoint:59 - Registering block manager localhost:35071 with 1918.1 MB RAM, BlockManagerId(driver, localhost, 35071) 
2016-03-23 09:57:00 INFO BlockManagerMaster:59 - Registered BlockManager 
2016-03-23 09:57:00 INFO SparkContext:59 - Invoking stop() from shutdown hook 

Answer 1

OK，我想我有一個jar不匹配問題。

這個thread把我引向它。

在我的POM我有以下依賴性：

<dependency> 
     <groupId>com.fasterxml.jackson.core</groupId> 
     <artifactId>jackson-databind</artifactId> 
     <version>2.7.1</version>   
    </dependency> 

看着罐子火花拉進我看到：jackson-module-scala_2.10-2.2.3.jar

我刪除了傑克遜的依賴，現在的測試通過！