Runtimeexception：java.lang.NoSuchMethodException：tfidf $ Reduce。< init>（） [英] Runtimeexception: java.lang.NoSuchMethodException: tfidf$Reduce.<init>()

问题描述

如何解决这个问题：tfidf是我的主要类
为什么运行jar文件后出现这个错误？

how to solve this problem:tfidf is my main class why this error coming after running jar file?

java.lang.RuntimeException: java.lang.NoSuchMethodException: tfidf$Reduce.<init>()
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:115)
    at org.apache.hadoop.mapred.Task$OldCombinerRunner.combine(Task.java:1423)
    at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:1436)
    at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:1298)
    at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:437)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:372)
    at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:396)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
    at org.apache.hadoop.mapred.Child.main(Child.java:249)
 Caused by: java.lang.NoSuchMethodException: tfidf$Reduce.<init>()
    at java.lang.Class.getConstructor0(Class.java:2715)
    at java.lang.Class.getDeclaredConstructor(Class.java:1987)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:109)
    ... 10 more

推荐答案

我认为这是试图实例化一个reducer。将您的reducer类声明为静态并尝试。

I think it is trying to instantiate a reducer. Declare your reducer class as static and try.

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