Initialization of all the collectors failed. Error in last collector was :class com.xx.mapreduce.w

突然遇到的，网上查找了很多说法，说是bean没有实现writable接口，nono！其实是一个灰常灰常低级灰常的错误！

Initialization of all the collectors failed. Error in last collector was :class com.xxx.mapreduce.webLog.WebLogMapper

伴随的还有：

 java.lang.ClassCastException:class.com.xx.mapreduce.webLog.WebLogMapper

灰常灰常低级灰常的错误!

driver里map的输出的类型错了

job.setMapOutputKeyClass(WebLogMapper.class);

应该是输出的数据类型Text.class类型，写成了加载mapper类了