最后修改过的build.xml如下：
?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
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">
<import file="../build-contrib.xml"/>
<path>
<fileset dir="${eclipse.home}/plugins/">
<include/>
<include/>
<include/>
<include/>
<include/>
<include/>
<include/>
<include/>
<include/>
<include/>
</fileset>
</path>
<!-- Override classpath to include Eclipse SDK jars -->
<path>
<pathelement location="${build.classes}"/>
<pathelement location="${Hadoop.root}/build/classes"/>
<path refid="eclipse-sdk-jars"/>
<fileset dir="${hadoop.root}/">
<include/>
</fileset>
</path>
<!-- Skip building if eclipse.home is unset. -->
<target unless="eclipse.home">
<property value="yes"/>
<echo message="eclipse.home unset: skipping eclipse plugin"/>
</target>
<target 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 depends="compile" unless="skip.contrib">
<mkdir dir="${build.dir}/lib"/>
<!-- <copy file="${hadoop.root}/build/hadoop-core-${version}.jar" tofile="${build.dir}/lib/hadoop-core.jar" verbose="true"/>
<copy file="${hadoop.root}/build/ivy/lib/Hadoop/common/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/>-->
<copy file="${hadoop.root}/hadoop-core-${version}.jar" tofile="${build.dir}/lib/hadoop-core.jar" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-cli-1.2.jar" todir="${build.dir}/lib" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-lang-2.4.jar" todir="${build.dir}/lib" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-configuration-1.6.jar" todir="${build.dir}/lib" verbose="true"/>
<copy file="${hadoop.root}/lib/jackson-mapper-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
<copy file="${hadoop.root}/lib/jackson-core-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
<copy file="${hadoop.root}/lib/commons-httpclient-3.0.1.jar" todir="${build.dir}/lib" verbose="true"/>
<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>
</project>
（2）配置/${hadoop-home}/src/contrib/build-contrib.xml
指定hadoop版本和eclipse路径，添加：
<property value="1.2.1"/>
<property value="2.1.0"/>
<property location="/home/summerdg/eclipse"/>
location下面是eclipse的解压路径。
（3）配置/${hadoop-home}/src/contrib/eclipse-plugins/META-INF/MANIFEST.MF
在Bundle-ClassPath: classes/,lib/hadoop-core.jar后边添加lib/jackson-core-asl-1.8.8.jar ,lib/jackson-mapper-asl-1.8.8.jar, lib/commons-configuration-1.6.jar,lib/commons-lang-2.4.jar, lib/commons-httpclient-3.0.1.jar,lib/commons-cli-1.2.jar，其他文章说不能另起一行，要紧挨着，所以最后该文件的样子就是：
Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: MapReduce Tools for Eclipse
Bundle-SymbolicName: org.apache.hadoop.eclipse;singleton:=true
Bundle-Version: 0.18
Bundle-Activator: org.apache.hadoop.eclipse.Activator
Bundle-Localization: plugin
Require-Bundle: org.eclipse.ui,
org.eclipse.core.runtime,
org.eclipse.jdt.launching,
org.eclipse.debug.core,
org.eclipse.jdt,
org.eclipse.jdt.core,
org.eclipse.core.resources,
org.eclipse.ui.ide,
org.eclipse.jdt.ui,
org.eclipse.debug.ui,
org.eclipse.jdt.debug.ui,
org.eclipse.core.expressions,
org.eclipse.ui.cheatsheets,
org.eclipse.ui.console,
org.eclipse.ui.navigator,
org.eclipse.core.filesystem,
org.apache.commons.logging
Eclipse-LazyStart: true
Bundle-ClassPath: classes/,lib/hadoop-core.jar,lib/jackson-core-asl-1.8.8.jar ,lib/jackson-mapper-asl-1.8.8.jar, lib/commons-configuration-1.6.jar,lib/commons-lang-2.4.jar, lib/commons-httpclient-3.0.1.jar,lib/commons-cli-1.2.jar
Bundle-Vendor: Apache Hadoop