在Windows上使用Eclipse配置Hadoop MapReduce开发环境

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1. 系统环境及所需文件

• windows 8.1 64bit
• Eclipse (Version: Luna Release 4.4.0)
• hadoop-eclipse-plugin-2.7.0.jar
• hadoop.dll & winutils.exe
  

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2. 修改Master节点的hdfs-site.xml

添加如下内容

<property>     <name>dfs.permissions</name>     <value>false</value> </property> 

旨在取消权限检查，原因是为了解决我在windows机器上配置eclipse连接hadoop服务器时，配置map/reduce连接后报以下错误，org.apache.hadoop.security.AccessControlException: Permission denied:

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3. 配置Hadoop插件

1. 将下载的hadoop-eclipse-plugin-2.7.0.jar文件放到Eclipse的plugins目录下，重启Eclipse即可看到该插件已生效
2. 创建New hadoop location， Eclipse菜单栏Window -> Show View -> Other MapReduce Tools -> Map/Reduce Locations

3. 配置完毕，查看效果

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4. 创建一个Map/Reduce Project

1. 新建项目 File–New–Other–Map/Reduce Project 命名为WordCount
   (从hadoop-2.6.0-cdh5.4.1源码中拷贝WordCount.java, F:\DevTools\hadoop-2.6.0-cdh5.4.1\src\hadoop-mapreduce-project\hadoop-mapreduce-examples\src\main\java\org\apache\hadoop\examples\WordCount.java)

2.java.lang.UnsatisfiedLinkError:org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)异常问题

修改Master节点中hadoop-2.6.0-cdh5.4.1\src\hadoop-common-project\hadoop-common\src\main\java\org\apache\hadoop\io\nativeio\NativeIO.java

然后在/src/hadoop-common-project/hadoop-common目录下 用maven重新编译jar包
mvn package -Pdist,native -DskipTests -Dtar -e -X
编译完成后会在hadoop-common/target生成相应的jar包只需要用hadoop-common-2.6.0-cdh5.4.1.jar替换掉windows下$HADOOP_HOME\share\hadoop\common目录对应的jar包

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5. windows下运行环境配置

将下载下来的hadoop.dll,winutils.exe拷贝到$HADOOP_HOME/bin目录下

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6. 运行WordCount Project

在eclipse中点击WordCount.java，右键，点击Run As—>Run Configurations，配置运行参数，即输入和输出文件夹

hdfs://Master:9000/input hdfs://Master:9000/output 

(注意：如果output目录已经存在，则删掉或换个名字，如output01，output02 。。。 )

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7. 运行结果