Mahout 0.9和Hadoop 2.2.0 - 发现接口org.apache.hadoop.mapreduce.JobContext，但类是预期的 [英] Mahout 0.9 and Hadoop 2.2.0 - Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected

问题描述

我的代码出错了？当我搜索时，我发现了一个类似的帖子，但无法适应我的问题。

Where did my code go wrong? When I searched, I found a similar post, but couldn't adapt it to my problem.

Exception in thread "main" java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected
    at org.apache.mahout.common.HadoopUtil.getCustomJobName(HadoopUtil.java:174)
    at org.apache.mahout.common.AbstractJob.prepareJob(AbstractJob.java:614)
    at org.apache.mahout.cf.taste.hadoop.preparation.PreparePreferenceMatrixJob.run(PreparePreferenceMatrixJob.java:73)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.run(RecommenderJob.java:164)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.mahout.cf.taste.hadoop.item.RecommenderJob.main(RecommenderJob.java:322)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
    at org.apache.hadoop.util.ProgramDriver.run(ProgramDriver.java:144)
    at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:152)
    at org.apache.mahout.driver.MahoutDriver.main(MahoutDriver.java:195)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)

推荐答案

这是一个已知的问题我相信，并将在Mahout 1.0中提供。如果您希望支持Hadoop 2.x，您可以尝试从trunk中重新编译mahout。

This is a known issue I believe and will be available in Mahout 1.0. If you want support for Hadoop 2.x, you can try re-compiling mahout from trunk.

已在此JIRA票证中修复： https://issues.apache.org/jira/browse/MAHOUT-1329

Fixed in this JIRA ticket: https://issues.apache.org/jira/browse/MAHOUT-1329

另外看看另一个类似的问题： Mahout Hadoop2.2错误

Also have a look at another similar question: Mahout error with Hadoop2.2

这篇关于Mahout 0.9和Hadoop 2.2.0 - 发现接口org.apache.hadoop.mapreduce.JobContext，但类是预期的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！