MapReduce在集群执行任务时报错：Initialization of all the collectors failed. Error in last collector was:java.lang.ClassCastException

报错信息详细：

Error: java.io.IOException: Initialization of all the collectors failed. Error in last collector was:java.lang.ClassCastException: 
class com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$Text
    at org.apache.hadoop.mapred.MapTask.createSortingCollector(MapTask.java:423)
    at org.apache.hadoop.mapred.MapTask.access$100(MapTask.java:82)
    at org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:710)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:782)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:347)
    at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:174)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1730)
    at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:168

仔细看以下这个信息： java.lang.ClassCastException:class com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$Text

ClassCastException:类转换异常，查找了自己写的代码，果然在Runner类里发现了导入的包错了。

修改成hadoop下的包：import org.apache.hadoop.io.Text;

修改完成后成功执行