根据官方文档（Apache Hadoop MapReduce - Migrating from Apache
Hadoop 1.x to Apache Hadoop 2.x：http://hadoop.apache.org/docs/r2.2.0/hadoop-mapreduce-client/hadoop-mapreduce-client-core/MapReduce_Compatibility_Hadoop1_Hadoop2.html）所述，Hadoop2.x是对Hadoop1.x程序兼容的，由于Hadoop2.x对Hadoop1.x做了重大的结构调整，很多程序依赖库被拆分了，所以以前（Hadoop1.x）的依赖库不再可用（不是说API不可用，而是api存放的包不一样），如果需要在Hadoop2.X上面编译，请用下面的依赖库：
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-mapreduce-client-core</artifactId> |
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-common</artifactId> |
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-mapreduce-client-common</artifactId> |
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-mapreduce-client-jobclient</artifactId> |
记得加上
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-mapreduce-client-common</artifactId> |
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<groupId>org.apache.hadoop</groupId> |
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<artifactId>hadoop-mapreduce-client-jobclient</artifactId> |
否则运行程序的时候将会出现一下的异常：
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Exception in thread "main"
java.io.IOException: Cannot initialize Cluster. |
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Please check your configuration
for mapreduce.framework.name and the
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correspond server addresses. |
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at org.apache.hadoop.mapreduce.Cluster.initialize(Cluster.java:120) |
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at org.apache.hadoop.mapreduce.Cluster.<init>(Cluster.java:82) |
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at org.apache.hadoop.mapreduce.Cluster.<init>(Cluster.java:75) |
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at org.apache.hadoop.mapred.JobClient.init(JobClient.java:465) |
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at org.apache.hadoop.mapred.JobClient.<init>(JobClient.java:444) |
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at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:826) |
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at com.wyp.hadoop.MaxTemperature.main(MaxTemperature.java:41) |
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at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) |
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at sun.reflect.NativeMethodAccessorImpl.invoke |
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(NativeMethodAccessorImpl.java:57) |
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at sun.reflect.DelegatingMethodAccessorImpl.invoke |
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(DelegatingMethodAccessorImpl.java:43) |
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at java.lang.reflect.Method.invoke(Method.java:606) |
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at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120) |
一个简单的Mapreduce程序请参见《编写简单的Mapreduce程序并部署在Hadoop2.2.0上运行》
如果你不是用Maven管理依赖的类库，你可以分别在${HADOOP_HOME}/share/hadoop/common和${HADOOP_HOME}/share/hadoop/mapreduce目录里面以下几个依赖库，分别是hadoop-mapreduce-client-core-2.2.0.jar、hadoop-common-2.2.0.jar、hadoop-mapreduce-client-common-2.2.0.jar、hadoop-mapreduce-client-jobclient-2.2.0.jar和上面的四个依赖正好对应。
转载自过往记忆（http://www.iteblog.com/）
本文链接地址:
《Hadoop1.x程序升级到Hadoop2.x需要的依赖库》（http://www.iteblog.com/archives/840）