RuntimeException:在运行我的UDAF时，用空指针异常配置对象时出错

Question

我一直在尝试编写一个用于计算加权平均值的UDAF。我用一种类似于现有UDAF的方式来计算平均值，但它似乎只在我的本地机器上工作。我不确定出了什么问题。。。。有人遇到过类似的问题吗以下是生成的错误：

java.lang.RuntimeException: Error in configuring object
    at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
    at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
    at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:413)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:348)
    at org.apache.hadoop.mapred.Child$4.run(Child.java:270)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at                        org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1127)
    at org.apache.hadoop.mapred.Child.main(Child.java:264)
Caused by: java.lang.reflect.InvocationTargetException
    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:601)
    at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88)
    ... 9 more
Caused by: java.lang.RuntimeException: Error in configuring object
     at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93)
    at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
    at org.apache.hadoop.mapred.MapRunner.configure(MapRunner.java:34)
    ... 14 more
Caused by: java.lang.reflect.InvocationTargetException
    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:601)
    at org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88)
    ... 17 more
Caused by: java.lang.RuntimeException: Map operator initialization failed
    at org.apache.hadoop.hive.ql.exec.ExecMapper.configure(ExecMapper.java:121)
    ... 22 more
Caused by: java.lang.NullPointerException
at org.apache.hadoop.hive.ql.exec.GroupByOperator.initializeOp(GroupByOperator.java:325)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:360)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:436)
    at org.apache.hadoop.hive.ql.exec.Operator.initializeChildren(Operator.java:392)
    at org.apache.hadoop.hive.ql.exec.SelectOperator.initializeOp(SelectOperator.java:62)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:360)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:436)
    at org.apache.hadoop.hive.ql.exec.Operator.initializeChildren(Operator.java:392)
    at org.apache.hadoop.hive.ql.exec.TableScanOperator.initializeOp(TableScanOperator.java:166)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:360)
    at org.apache.hadoop.hive.ql.exec.MapOperator.initializeOp(MapOperator.java:441)
    at org.apache.hadoop.hive.ql.exec.Operator.initialize(Operator.java:360)
    at org.apache.hadoop.hive.ql.exec.ExecMapper.configure(ExecMapper.java:98)
    ... 22 more

Answer 1

我解决了这个问题。。似乎有一些jar文件问题。。。每当我导出时，有些更改会起作用，而有些则不起作用，所以我想答案是每次你计划添加jar文件时都终止你的配置单元会话！：/奇怪，但它起作用了。。。

Answer 2

在我的例子中，我运行了Hive查询（从使用serde jar创建的表中选择语句），但当我进行选择查询时，类路径中缺少jar。因此，我使用以下命令将jar添加到hive shall的类路径中：-

添加jar/usr/lib/hive/lib/hive-control-0.7.0-cdh3u0.jar；

然后进行select查询，它解决了我的问题。