[java] 15/12/19 14:09:46 INFO mapred.JobClient: Task Id : attempt_201512182036_0017_m_000000_0, Status : FAILED
[java] java.lang.RuntimeException: java.lang.NoSuchMethodException: org.lukey.hadoop.tianyi.TianYiBigData$MyMapper.<init>()
[java] at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:115)
[java] at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:719)
[java] at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
[java] at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
[java] at java.security.AccessController.doPrivileged(Native Method)
[java] at javax.security.auth.Subject.doAs(Subject.java:422)
[java] at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
[java] at org.apache.hadoop.mapred.Child.main(Child.java:249)
[java] Caused by: java.lang.NoSuchMethodException: org.lukey.hadoop.tianyi.TianYiBigData$MyMapper.<init>()
[java] at java.lang.Class.getConstructor0(Class.java:3082)
[java] at java.lang.Class.getDeclaredConstructor(Class.java:2178)
[java] at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:109)
[java] ... 7 more
需要在MyMapper前面加static。
If the class is an inner class, make sure it's declared static (i.e. doesn't need an instance of the enclosing class). Otherwise, Hadoop cannot instantiate your inner class and will give this same error - that a zero-arg constructor is needed.
http://stackoverflow.com/questions/11446635/no-such-method-exception-hadoop-init