一、要想在eclipse上运行hadoop，首先要依次解决下面问题：
1、安装jdk
2、安装ant
3、安装eclipse
4、安装hadoop
5、编译hadoop-eclipse-plugin插件
前面四个网上方案很多，但是却参差不齐，很多都是敷衍了事，于是我整理了一些优秀的文章，按照上面来，几乎没什么问题（对于小白，一定要注意路径问题，别到后面自己都不知道自己安装了什么）
1、安装jdk（注意，这里会出现一些小问题，例如本机已经安装了openjdk，可以百度）
2、安装ant（这个很简单，但是也要记住，在配置文件的时候，也是在前面jdk配置文件（sudo gedit /etc/profile）那里添加）
3、安装eclipse（这里jdk就不用重新安装了，选择下载java EE，毕竟什么都有）
4、安装hadoop（免密登录，貌似这伙有问题，再贴一个，大家可以参考这个人的免密登录）
5、编译hadoop-eclipse-plugin（这个很麻烦，而且网上的教程写的很乱，而且大多很老或者没用，主要是版本的更新）
二、如何编译hadoop-eclipse-plugin文件
1、首先，大家一般都是hadoop-2.*，所以可以在GitHub上下载提供的hadoop-eclipse-plugin
2、下载完之后，直接进行解压，然后打开hadoop2x-eclipse-plugin-master --->ivy ---->libraries.properties
打开之后是这样的（当然，这是我更改之后的，我使用的是hadoop-2.7.6，如果你跟我一样，可以直接跳，在文章末尾下载编译好的）
# Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. #This properties file lists the versions of the various artifacts used by hadoop and components. #It drives ivy and the generation of a maven POM # This is the version of hadoop we are generating hadoop.version=2.7.6 hadoop-gpl-compression.version=0.1.0 #These are the versions of our dependencies (in alphabetical order) apacheant.version=1.7.0 ant-task.version=2.0.10 asm.version=3.2 aspectj.version=1.6.5 aspectj.version=1.6.11 checkstyle.version=4.2 commons-cli.version=1.2 commons-codec.version=1.4 commons-collections.version=3.2.2 commons-configuration.version=1.6 commons-daemon.version=1.0.13 commons-httpclient.version=4.2.5 commons-lang.version=2.6 commons-logging.version=1.1.3 commons-logging-api.version=1.0.4 commons-math.version=2.1 commons-el.version=1.0 commons-fileupload.version=1.2 commons-io.version=2.4 commons-net.version=3.1 core.version=3.1.1 coreplugin.version=1.3.2 hsqldb.version=1.8.0.10 htrace.version=3.0.4 ivy.version=2.1.0 jasper.version=5.5.12 jackson.version=1.9.13 #not able to figureout the version of jsp & jsp-api version to get it resolved throught ivy # but still declared here as we are going to have a local copy from the lib folder jsp.version=2.1 jsp-api.version=5.5.12 jsp-api-2.1.version=6.1.14 jsp-2.1.version=6.1.14 jets3t.version=0.9.0 jetty.version=6.1.26 jetty-util.version=6.1.26 jersey-core.version=1.9 jersey-json.version=1.9 jersey-server.version=1.9 junit.version=4.11 jdeb.version=0.8 jdiff.version=1.0.9 json.version=1.0 kfs.version=0.1 log4j.version=1.2.17 lucene-core.version=2.3.1 mockito-all.version=1.8.5 jsch.version=0.1.54 oro.version=2.0.8 rats-lib.version=0.5.1 servlet.version=4.0.6 servlet-api.version=2.5 slf4j-api.version=1.7.10 slf4j-log4j12.version=1.7.10 wagon-http.version=1.0-beta-2 xmlenc.version=0.52 xerces.version=1.4.4 protobuf.version=2.5.0 guava.version=11.0.2 netty.version=3.6.2.Final
3、找到你最开始放置解压后hadoop文件的地方
打开hadoop文件 ----> share ----> hadoop ---->common ----->lib
打开后是这样的:
根据这个来更改版本（重点），比如前面
log4j.version=1.2.17（最开始我是log4j.version=1.2.10的，但是根据上面最下面一排，左边第三个，发现是1.2.17，所以需要改为log4j.version=1.2.17）
4、更改build.xml(重点，因为随着版本不同，有些jar包的名称发生改变)
打开hadoop2x-eclipse-plugin-master ---> src ----> contrib ---->eclipse-plugin ---->build.xml
(注意，有些版本不同，可能位置会不一样，只要在hadoop2x-eclipse-plugin-master找到eclipse-plugin就行)
打开后：
<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!-- Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <project default="jar" name="eclipse-plugin"> <import file="../build-contrib.xml"/> <path id="eclipse-sdk-jars"> <fileset dir="${eclipse.home}/plugins/"> <include name="org.eclipse.ui*.jar"/> <include name="org.eclipse.jdt*.jar"/> <include name="org.eclipse.core*.jar"/> <include name="org.eclipse.equinox*.jar"/> <include name="org.eclipse.debug*.jar"/> <include name="org.eclipse.osgi*.jar"/> <include name="org.eclipse.swt*.jar"/> <include name="org.eclipse.jface*.jar"/> <include name="org.eclipse.team.cvs.ssh2*.jar"/> <include name="com.jcraft.jsch*.jar"/> </fileset> </path> <path id="hadoop-sdk-jars"> <fileset dir="${hadoop.home}/share/hadoop/mapreduce"> <include name="hadoop*.jar"/> </fileset> <fileset dir="${hadoop.home}/share/hadoop/hdfs"> <include name="hadoop*.jar"/> </fileset> <fileset dir="${hadoop.home}/share/hadoop/common"> <include name="hadoop*.jar"/> </fileset> </path> <!-- Override classpath to include Eclipse SDK jars --> <path id="classpath"> <pathelement location="${build.classes}"/> <!--pathelement location="${hadoop.root}/build/classes"/--> <path refid="eclipse-sdk-jars"/> <path refid="hadoop-sdk-jars"/> </path> <!-- Skip building if eclipse.home is unset. --> <target name="check-contrib" unless="eclipse.home"> <property name="skip.contrib" value="yes"/> <echo message="eclipse.home unset: skipping eclipse plugin"/> </target> <target name="compile" depends="init, ivy-retrieve-common" unless="skip.contrib"> <echo message="contrib: ${name}"/> <javac encoding="${build.encoding}" srcdir="${src.dir}" includes="**/*.java" destdir="${build.classes}" debug="${javac.debug}" deprecation="${javac.deprecation}"> <classpath refid="classpath"/> </javac> </target> <!-- Override jar target to specify manifest --> <target name="jar" depends="compile" unless="skip.contrib"> <mkdir dir="${build.dir}/lib"/> <copy todir="${build.dir}/lib/" verbose="true"> <fileset dir="${hadoop.home}/share/hadoop/mapreduce"> <include name="hadoop*.jar"/> </fileset> </copy> <copy todir="${build.dir}/lib/" verbose="true"> <fileset dir="${hadoop.home}/share/hadoop/common"> <include name="hadoop*.jar"/> </fileset> </copy> <copy todir="${build.dir}/lib/" verbose="true"> <fileset dir="${hadoop.home}/share/hadoop/hdfs"> <include name="hadoop*.jar"/> </fileset> </copy> <copy todir="${build.dir}/lib/" verbose="true"> <fileset dir="${hadoop.home}/share/hadoop/yarn"> <include name="hadoop*.jar"/> </fileset> </copy> <copy todir="${build.dir}/classes" verbose="true"> <fileset dir="${root}/src/java"> <include name="*.xml"/> </fileset> </copy> <copy file="${hadoop.home}/share/hadoop/common/lib/protobuf-java-${protobuf.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/log4j-${log4j.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-configuration-${commons-configuration.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-lang-${commons-lang.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-collections-${commons-collections.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/jackson-core-asl-${jackson.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/jackson-mapper-asl-${jackson.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/slf4j-log4j12-${slf4j-log4j12.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/slf4j-api-${slf4j-api.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/guava-${guava.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/hadoop-auth-${hadoop.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/netty-${netty.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/htrace-core-${htrace.version}.jar" todir="${build.dir}/lib" verbose="true"/> <jar jarfile="${build.dir}/hadoop-${name}-${hadoop.version}.jar" manifest="${root}/META-INF/MANIFEST.MF"> <manifest> <attribute name="Bundle-ClassPath" value="classes/, lib/hadoop-mapreduce-client-core-${hadoop.version}.jar, lib/hadoop-mapreduce-client-common-${hadoop.version}.jar, lib/hadoop-mapreduce-client-jobclient-${hadoop.version}.jar, lib/hadoop-auth-${hadoop.version}.jar, lib/hadoop-common-${hadoop.version}.jar, lib/hadoop-hdfs-${hadoop.version}.jar, lib/protobuf-java-${protobuf.version}.jar, lib/log4j-${log4j.version}.jar, lib/commons-cli-${commons-cli.version}.jar, lib/commons-configuration-${commons-configuration.version}.jar, lib/commons-httpclient-${commons-httpclient.version}.jar, lib/commons-lang-${commons-lang.version}.jar, lib/commons-collections-${commons-collections.version}.jar, lib/jackson-core-asl-${jackson.version}.jar, lib/jackson-mapper-asl-${jackson.version}.jar, lib/slf4j-log4j12-${slf4j-log4j12.version}.jar, lib/slf4j-api-${slf4j-api.version}.jar, lib/guava-${guava.version}.jar, lib/netty-${netty.version}.jar, lib/htrace-core-${htrace.version}.jar"/> </manifest> <fileset dir="${build.dir}" includes="classes/ lib/"/> <!--fileset dir="${build.dir}" includes="*.xml"/--> <fileset dir="${root}" includes="resources/ plugin.xml"/> </jar> </target> </project> <copy file="${hadoop.home}/share/hadoop/common/lib/protobuf-java-${protobuf.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/log4j-${log4j.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-configuration-${commons-configuration.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-lang-${commons-lang.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-collections-${commons-collections.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/jackson-core-asl-${jackson.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/jackson-mapper-asl-${jackson.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/slf4j-log4j12-${slf4j-log4j12.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/slf4j-api-${slf4j-api.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/guava-${guava.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/hadoop-auth-${hadoop.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/netty-${netty.version}.jar" todir="${build.dir}/lib" verbose="true"/> <copy file="${hadoop.home}/share/hadoop/common/lib/htrace-core-${htrace.version}.jar" todir="${build.dir}/lib" verbose="true"/> <jar jarfile="${build.dir}/hadoop-${name}-${hadoop.version}.jar" manifest="${root}/META-INF/MANIFEST.MF"> <manifest> <attribute name="Bundle-ClassPath" value="classes/, lib/hadoop-mapreduce-client-core-${hadoop.version}.jar, lib/hadoop-mapreduce-client-common-${hadoop.version}.jar, lib/hadoop-mapreduce-client-jobclient-${hadoop.version}.jar, lib/hadoop-auth-${hadoop.version}.jar, lib/hadoop-common-${hadoop.version}.jar, lib/hadoop-hdfs-${hadoop.version}.jar, lib/protobuf-java-${protobuf.version}.jar, lib/log4j-${log4j.version}.jar, lib/commons-cli-${commons-cli.version}.jar, lib/commons-configuration-${commons-configuration.version}.jar, lib/commons-httpclient-${commons-httpclient.version}.jar, lib/commons-lang-${commons-lang.version}.jar, lib/commons-collections-${commons-collections.version}.jar, lib/jackson-core-asl-${jackson.version}.jar, lib/jackson-mapper-asl-${jackson.version}.jar, lib/slf4j-log4j12-${slf4j-log4j12.version}.jar, lib/slf4j-api-${slf4j-api.version}.jar, lib/guava-${guava.version}.jar, lib/netty-${netty.version}.jar, lib/htrace-core-${htrace.version}.jar"/> </manifest> <fileset dir="${build.dir}" includes="classes/ lib/"/> <!--fileset dir="${build.dir}" includes="*.xml"/--> <fileset dir="${root}" includes="resources/ plugin.xml"/> </jar> </target> </project>
<copy file="${hadoop.home}/share/hadoop/common/lib/htrace-core-${htrace.version}.jar" todir="${build.dir}/lib" verbose="true"/>
在前面的jar包里没有htrace-core-...jar只有htrace-core-3.1.0-incubating.jar，所以更改为：
当然，如果出现其他类似错误，对照更改就行（当然，是在报错，备份后，尝试删除部分）
5、最后开始进行编译工作
在hadoop2x-eclipse-plugin-master ---> src ----> contrib ---->eclipse-plugin文件夹中执行：
ant jar -Dversion=2.7.6 -Declipse.home=/opt/eclipse -Dhadoop.home=/home/gambler/hadoop-2.7.6
注意 -Dversion=你的hadoop版本，-Declipse.home=你的eclipse文件路径，-Dhadoop=你的hadoop文件路径，
还有关键的一点是，它创建jar包的默认路径是hadoop2x-eclipse-plugin-master ---->build ---->contrib ---->eclipse-plugin，如果没有的话可以提前创建一个，至少需要build文件夹，否则会报错
编译完成后出现下面这个表示成功：
三、使用eclipse创建MapReduce工程
1、首先将编译好的jar包移动到eclipse ----> plugins中去
命令是： sudo mv hadoop-eclipse-plugin-2.7.6 .jar /你的eclipse文件/plugins
2、启动eclipse，可以直接在search中搜索eclipse，
新建一个工程，找到MapReduce，会出现下面这种问题（invalid Hadoop Runtime specified;please click'Configure Hadoop install directory'）
点击右下边的'Configure Hadoop install directory'
在里面填入/hadoop的绝对路径/share/hadoop/mapreduce
填完之后点击完成，然后就OK了，最后放一张成功的图，博主也是刚刚建好的；
好累啊，写完这个，麻烦大伙要是觉得还ok，就点个赞！！！
最后的编译完成的后的jar包
