从hadoop 0.20.203以后，hadoop的发布包里，不再对eclipse插件进行jar包发布，而是给出了打包的代码，需要各位开发人员自己进行打包和设置。我们打的包必须跟自己使用的hadoop版本一致
第一步：先下载hadoop版本，我们这里以hadoop-1.2.1.tar.gz为例，解压，把这个项目全部倒入到MyEclipse里
File-----import----
选择项目导入
第二步 我们要修改Hadoop根目录下的src/contrib/META-INFO/MANIFEST.MF，修改这个jar的classpath。
找到这个文件的Bundle-ClassPath这一行，然后，修改成
Bundle-ClassPath: classes/,lib/commons-cli.jar,lib/commons-httpclient.jar,lib/hadoop-core.jar,lib/jackson-mapper-asl.jar,lib/commons-configuration.jar,lib/commons-lang.jar,lib/jackson-core-asl.jar
这些jar包都可以在hadoop文件里面搜索到
第三步：修改build.xml文件，修改的地方我用红色标记了，一个是myeclipse位置，另一个是hadoop版本，其它还是原封不动
<?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="deploy" name="eclipse-plugin">
<import file="../build-contrib.xml"/>
<property name="eclipse.home" location="D:/Program Files/MyEclipse"/>
<property name="version" value="1.2.1"/>
<path id="eclipse-sdk-jars">
<fileset dir="${eclipse.home}/plugins/">
<include name="org.eclipse.ui*.jar"/>
<include name="org.eclipse.jdt*.jar"/>
<include name="org.eclipse.core*.jar"/>
<include name="org.eclipse.equinox*.jar"/>
<include name="org.eclipse.debug*.jar"/>
<include name="org.eclipse.osgi*.jar"/>
<include name="org.eclipse.swt*.jar"/>
<include name="org.eclipse.jface*.jar"/>
<include name="org.eclipse.team.cvs.ssh2*.jar"/>
<include name="com.jcraft.jsch*.jar"/>
</fileset>
</path>
<!-- Override classpath to include Eclipse SDK jars -->
<path id="classpath">
<pathelement location="${build.classes}"/>
<pathelement location="${hadoop.root}/build/classes"/>
<fileset dir="${hadoop.root}">
<include name="**/*.jar" />
</fileset>
<path refid="eclipse-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}"
includeantruntime="on">
<classpath refid="classpath"/>
</javac>
</target>
<!-- Override jar target to specify manifest -->
<target name="jar" depends="compile" unless="skip.contrib">
<mkdir dir="${build.dir}/lib"/>
<copy file="${hadoop.root}/hadoop-core-${version}.jar" tofile="${build.dir}/lib/hadoop-core.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-cli-${commons-cli.version}.jar" tofile="${build.dir}/lib/commons-cli.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-configuration-1.6.jar" tofile="${build.dir}/lib/commons-configuration.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-httpclient-3.0.1.jar" tofile="${build.dir}/lib/commons-httpclient.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-lang-2.4.jar" tofile="${build.dir}/lib/commons-lang.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/jackson-core-asl-1.8.8.jar" tofile="${build.dir}/lib/jackson-core-asl.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/jackson-mapper-asl-1.8.8.jar" tofile="${build.dir}/lib/jackson-mapper-asl.jar" verbose="true"/>
<echo message="${build.dir}"/>
<echo message="${root}"/>
<jar
jarfile="${build.dir}/hadoop-${name}-${version}.jar"
manifest="${root}/META-INF/MANIFEST.MF">
<fileset dir="${build.dir}" includes="classes/ lib/"/>
<fileset dir="${root}" includes="resources/ plugin.xml"/>
</jar>
</target>
<target name="deploy" depends="jar" unless="skip.contrib">
<copy file="${build.dir}/hadoop-${name}-${version}.jar" todir="${eclipse.home}/plugins" verbose="true"/>
</target>
</project>
第四步：点击window----Show View-----other----Ant----ok
会出现一个图标，点击项目中的build.xml选择OK，就会自动打包，打完插件。会放到F:\hadoop-1.2.1\build\contrib\eclipse-plugin这个目录下面。
这个目录是原先下载hadoop原路径。