重新编译hadoop

A. hadoop 重新编译，提示如下错误，怎么个意思了

第一次编辑错误提示
主要是增加了在maven目录下，conf/settings.xml
<mirror>
<id>nexus-osc</id>
<mirrorOf>*</mirrorOf>
<name>Nexusosc</name>
<url>http://maven.oschina.net/content/groups/public/</url>
</mirror>

<profile>
<id>jdk-1.7</id>
<activation>
<jdk>1.7</jdk>
</activation>
<repositories>
<repository>
<id>nexus</id>
<name>local private nexus</name>
<url>http://maven.oschina.net/content/groups/public/</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>nexus</id>
<name>local private nexus</name>
<url>http://maven.oschina.net/content/groups/public/</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
</profile>

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO]
[INFO] Apache Hadoop Main ................................. FAILURE [06:34 min]
[INFO] Apache Hadoop Project POM .......................... SKIPPED
[INFO] Apache Hadoop Annotations .......................... SKIPPED
[INFO] Apache Hadoop Assemblies ........................... SKIPPED
[INFO] Apache Hadoop Project Dist POM ..................... SKIPPED
[INFO] Apache Hadoop Maven Plugins ........................ SKIPPED
[INFO] Apache Hadoop MiniKDC .............................. SKIPPED
[INFO] Apache Hadoop Auth ................................. SKIPPED
[INFO] Apache Hadoop Auth Examples ........................ SKIPPED
[INFO] Apache Hadoop Common ............................... SKIPPED
[INFO] Apache Hadoop NFS .................................. SKIPPED
[INFO] Apache Hadoop Common Project ....................... SKIPPED
[INFO] Apache Hadoop HDFS ................................. SKIPPED
[INFO] Apache Hadoop HttpFS ............................... SKIPPED
[INFO] Apache Hadoop HDFS BookKeeper Journal .............. SKIPPED
[INFO] Apache Hadoop HDFS-NFS ............................. SKIPPED
[INFO] Apache Hadoop HDFS Project ......................... SKIPPED
[INFO] hadoop-yarn ........................................ SKIPPED
[INFO] hadoop-yarn-api .................................... SKIPPED
[INFO] hadoop-yarn-common ................................. SKIPPED
[INFO] hadoop-yarn-server ................................. SKIPPED
[INFO] hadoop-yarn-server-common .......................... SKIPPED
[INFO] hadoop-yarn-server-nodemanager ..................... SKIPPED
[INFO] hadoop-yarn-server-web-proxy ....................... SKIPPED
[INFO] hadoop-yarn-server-applicationhistoryservice ....... SKIPPED
[INFO] hadoop-yarn-server-resourcemanager ................. SKIPPED
[INFO] hadoop-yarn-server-tests ........................... SKIPPED
[INFO] hadoop-yarn-client ................................. SKIPPED
[INFO] hadoop-yarn-applications ........................... SKIPPED
[INFO] hadoop-yarn-applications-distributedshell .......... SKIPPED
[INFO] hadoop-yarn-applications-unmanaged-am-launcher ..... SKIPPED
[INFO] hadoop-yarn-site ................................... SKIPPED
[INFO] hadoop-yarn-project ................................ SKIPPED
[INFO] hadoop-maprece-client ............................ SKIPPED
[INFO] hadoop-maprece-client-core ....................... SKIPPED
[INFO] hadoop-maprece-client-common ..................... SKIPPED
[INFO] hadoop-maprece-client-shuffle .................... SKIPPED
[INFO] hadoop-maprece-client-app ........................ SKIPPED
[INFO] hadoop-maprece-client-hs ......................... SKIPPED
[INFO] hadoop-maprece-client-jobclient .................. SKIPPED
[INFO] hadoop-maprece-client-hs-plugins ................. SKIPPED
[INFO] Apache Hadoop MapRece Examples ................... SKIPPED
[INFO] hadoop-maprece ................................... SKIPPED
[INFO] Apache Hadoop MapRece Streaming .................. SKIPPED
[INFO] Apache Hadoop Distributed Copy ..................... SKIPPED
[INFO] Apache Hadoop Archives ............................. SKIPPED
[INFO] Apache Hadoop Rumen ................................ SKIPPED
[INFO] Apache Hadoop Gridmix .............................. SKIPPED
[INFO] Apache Hadoop Data Join ............................ SKIPPED
[INFO] Apache Hadoop Extras ............................... SKIPPED
[INFO] Apache Hadoop Pipes ................................ SKIPPED
[INFO] Apache Hadoop OpenStack support .................... SKIPPED
[INFO] Apache Hadoop Client ............................... SKIPPED
[INFO] Apache Hadoop Mini-Cluster ......................... SKIPPED
[INFO] Apache Hadoop Scheler Load Simulator ............. SKIPPED
[INFO] Apache Hadoop Tools Dist ........................... SKIPPED
[INFO] Apache Hadoop Tools ................................ SKIPPED
[INFO] Apache Hadoop Distribution ......................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 10:10 min
[INFO] Finished at: 2015-01-12T00:52:27-08:00
[INFO] Final Memory: 29M/70M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.3:attach-descriptor (attach-descriptor) on project hadoop-main: Execution attach-descriptor of goal org.apache.maven.plugins:maven-site-plugin:3.3:attach-descriptor failed: Plugin org.apache.maven.plugins:maven-site-plugin:3.3 or one of its dependencies could not be resolved: Failed to collect dependencies at org.apache.maven.plugins:maven-site-plugin:jar:3.3 -> org.apache.maven.reporting:maven-reporting-exec:jar:1.1 -> org.apache.maven.shared:maven-shared-utils:jar:0.3: Failed to read artifact descriptor for org.apache.maven.shared:maven-shared-utils:jar:0.3: Could not transfer artifact org.apache.maven.shared:maven-shared-utils:pom:0.3 from/to nexus-osc (http://maven.oschina.net/content/groups/public/): Failed to transfer file:http://maven.oschina.net/content/groups/public/org/apache/maven/shared/maven-shared-utils/0.3/maven-shared-utils-0.3.pom. Return code is: 502, ReasonPhrase: Bad Gateway. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResolutionException
[hadoop@localhost hadoop-2.5.0-src]$

B. 如何编译Apache Hadoop2.2.0源代码

下载hadoop-2.2.0-src.tar.gz 下载。

执行以下命令解压缩jdk
tar -zxvf hadoop-2.2.0-src.tar.gz

会生成一个文件夹 hadoop-2.2.0-src。源代码中有个bug，这里需要修改一下，编辑目录/usr/local/hadoop-2.2.0-src/hadoop-common-project/hadoop-auth中的文件pom.xml，执行以下命令
gedit pom.xml
在第55行下增加以下内容
<dependency>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-util</artifactId>
<scope>test</scope>
</dependency>

保存退出即可。

上述bug详见https://issues.apache.org/jira/browse/HADOOP-10110，在hadoop3中修复了，离我们太遥远了。

好了，现在进入到目录/usr/local/hadoop-2.2.0-src中，执行命令
mvn package -DskipTests -Pdist,native,docs
如果没有执行第4步，把上面命令中的docs去掉即可，就不必生成文档了。
该命令会从外网下载依赖的jar，编译hadoop源码，需要花费很长时间，你可以吃饭了。
在等待n久之后，可以看到如下的结果：
[INFO] Apache Hadoop Main ................................ SUCCESS [6.936s]
[INFO] Apache Hadoop Project POM ......................... SUCCESS [4.928s]
[INFO] Apache Hadoop Annotations ......................... SUCCESS [9.399s]
[INFO] Apache Hadoop Assemblies .......................... SUCCESS [0.871s]
[INFO] Apache Hadoop Project Dist POM .................... SUCCESS [7.981s]
[INFO] Apache Hadoop Maven Plugins ....................... SUCCESS [8.965s]
[INFO] Apache Hadoop Auth ................................ SUCCESS [39.748s]
[INFO] Apache Hadoop Auth Examples ....................... SUCCESS [11.081s]
[INFO] Apache Hadoop Common .............................. SUCCESS [10:41.466s]
[INFO] Apache Hadoop NFS ................................. SUCCESS [26.346s]
[INFO] Apache Hadoop Common Project ...................... SUCCESS [0.061s]
[INFO] Apache Hadoop HDFS ................................ SUCCESS [12:49.368s]
[INFO] Apache Hadoop HttpFS .............................. SUCCESS [41.896s]
[INFO] Apache Hadoop HDFS BookKeeper Journal ............. SUCCESS [41.043s]
[INFO] Apache Hadoop HDFS-NFS ............................ SUCCESS [9.650s]
[INFO] Apache Hadoop HDFS Project ........................ SUCCESS [0.051s]
[INFO] hadoop-yarn ....................................... SUCCESS [1:22.693s]
[INFO] hadoop-yarn-api ................................... SUCCESS [1:20.262s]
[INFO] hadoop-yarn-common ................................ SUCCESS [1:30.530s]
[INFO] hadoop-yarn-server ................................ SUCCESS [0.177s]
[INFO] hadoop-yarn-server-common ......................... SUCCESS [15.781s]
[INFO] hadoop-yarn-server-nodemanager .................... SUCCESS [40.800s]
[INFO] hadoop-yarn-server-web-proxy ...................... SUCCESS [6.099s]
[INFO] hadoop-yarn-server-resourcemanager ................ SUCCESS [37.639s]
[INFO] hadoop-yarn-server-tests .......................... SUCCESS [4.516s]
[INFO] hadoop-yarn-client ................................ SUCCESS [25.594s]
[INFO] hadoop-yarn-applications .......................... SUCCESS [0.286s]
[INFO] hadoop-yarn-applications-distributedshell ......... SUCCESS [10.143s]
[INFO] hadoop-maprece-client ........................... SUCCESS [0.119s]
[INFO] hadoop-maprece-client-core ...................... SUCCESS [55.812s]
[INFO] hadoop-yarn-applications-unmanaged-am-launcher .... SUCCESS [8.749s]
[INFO] hadoop-yarn-site .................................. SUCCESS [0.524s]
[INFO] hadoop-yarn-project ............................... SUCCESS [16.641s]
[INFO] hadoop-maprece-client-common .................... SUCCESS [40.796s]
[INFO] hadoop-maprece-client-shuffle ................... SUCCESS [7.628s]
[INFO] hadoop-maprece-client-app ....................... SUCCESS [24.066s]
[INFO] hadoop-maprece-client-hs ........................ SUCCESS [13.243s]
[INFO] hadoop-maprece-client-jobclient ................. SUCCESS [16.670s]
[INFO] hadoop-maprece-client-hs-plugins ................ SUCCESS [3.787s]
[INFO] Apache Hadoop MapRece Examples .................. SUCCESS [17.012s]
[INFO] hadoop-maprece .................................. SUCCESS [6.459s]
[INFO] Apache Hadoop MapRece Streaming ................. SUCCESS [12.149s]
[INFO] Apache Hadoop Distributed Copy .................... SUCCESS [15.968s]
[INFO] Apache Hadoop Archives ............................ SUCCESS [5.851s]
[INFO] Apache Hadoop Rumen ............................... SUCCESS [18.364s]
[INFO] Apache Hadoop Gridmix ............................. SUCCESS [14.943s]
[INFO] Apache Hadoop Data Join ........................... SUCCESS [9.648s]
[INFO] Apache Hadoop Extras .............................. SUCCESS [5.763s]
[INFO] Apache Hadoop Pipes ............................... SUCCESS [16.289s]
[INFO] Apache Hadoop Tools Dist .......................... SUCCESS [3.261s]
[INFO] Apache Hadoop Tools ............................... SUCCESS [0.043s]
[INFO] Apache Hadoop Distribution ........................ SUCCESS [56.188s]
[INFO] Apache Hadoop Client .............................. SUCCESS [10.910s]
[INFO] Apache Hadoop Mini-Cluster ........................ SUCCESS [0.321s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 40:00.444s
[INFO] Finished at: Thu Dec 26 12:42:24 CST 2013
[INFO] Final Memory: 109M/362M
[INFO] ------------------------------------------------------------------------

C. 怎么自己动手编译hadoop的eclipse插件

1.在linux环境中伪分布式部署hadoop(SSH免登陆)，运行WordCount实例成功。 http://www.cnblogs.com/PurpleDream/p/4009070.html

2.自己打包hadoop在eclipse中的插件。 http://www.cnblogs.com/PurpleDream/p/4014751.html

3.在eclipse中访问hadoop运行WordCount成功。

所以我下边会分三次记录下我的过程，为自己以后查阅方便，要是能帮助到其他人，自然是更好了！

===============================================================长长的分割线====================================================================

正文:

如果你想在eclipse中安装hadoop的插件，一个很重要的问题就是hadoop的版本与eclipse版本的匹配问题，如果不匹配，可能会导致很多问题。

综上，我在完成了在Linux的CentOS系统中安装hadoop并简单运行WordCount之后(具体参看本文前言中的博客链接)，将学习的重点放到了hadoop的eclipse插件上。其实网上也有部分文章在介绍如何编写插件，但是由于我的eclispe版本是Juno，而之前在CentOS安装的是hadoop-1.0.1，所以没有找到完全匹配的成功案例。所以最终决定自己也动手变异一个自己的hadoop插件。

在有了这个想法之后，一开始会觉得特别困难，但是在真正去做之后，会发现很多问题其实还是可以解决的，只要你懂得如果使用网络和谷歌，多参考一下别人的文章，汲取精华，最终一定会成功的。

第一步，确定大致流程:

1.首先我需要ant编译，然后就是hadoop-1.0.1.tar.gz这个安装包，还有就是eclipse。

2.针对我自己的环境，电脑是Win7，eclispe是Juno，下载了hadoop-1.0.1.tar.gz，就差ant之前没有安装。

第二步，安装ant：

1.我参考的是这篇文章http://blog.csdn.net/yang382197207/article/details/10185251，我当时下载的是apache-ant-1.9.4，其他的步骤按照这篇文章介绍的配置就会成功。

第三步，在正式建立项目之前，我在介绍下我的环境： OS: windows 7, Eclipse: Juno, JDK: 1.6.0_43, Hadoop: 1.0.1

1.首先在Eclipse中新建一个java项目，名字叫hadoop-1.0.1-eclipse-plugin，其实这个名字你可以随意的。

2.解压hadoop-1.0.1.tar.gz，在解压后的目录中(我的是D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1)，依次将下面的文件放到项目中:

(1).将\hadoop-1.0.1\src\contrib\eclipse-plugin里面的所有文件以及\hadoop-1.0.1\src\contrib\build-contrib.xml拖拽到项目中

(2).将根目录\hadoop-1.0.1里的所有.jar文件拖拽到eclipse项目中bin目录下。

3.打开项目中的build-contrib.xml，做如下的配置：

(1).找到<property name="hadoop.root" location="hadoop-1.0.1解压缩后的目录"/>

(2).找到<property name="eclipse.home" location="自己的eclipse的目录"/>

(3).找到<property name="version" value="hadoop的版本号"/>

可以参考我的配置，如图:

view sourceprint?
1.
<property name="name" value="${ant.project.name}"/>
2.
<property name="root" value="${basedir}"/>
3.
<property name="hadoop.root" location="D:/SettingUp/ITSettingUp/Hadoop/hadoop-1.0/hadoop-1.0.1"/>
4.
<property name="eclipse.home" location="D:/HaveSetted/ITHaveSetted/Eclipse"/>
5.
<property name="version" value="1.0.1"/>
4.打开项目中的build.xml，做如下的配置：

(1).将文件开头的 <import file="../build-contrib.xml"/> 修改为 <import file="build-contrib.xml"/>

(2).在<javac...>里如下图加入includeantruntime="on"，效果如下：

view sourceprint?
01.
<target name="compile" depends="init, ivy-retrieve-common" unless="skip.contrib">
02.
<echo message="contrib: ${name}"/>
03.
<javac
04.
encoding="${build.encoding}"
05.
srcdir="${src.dir}"
06.
includes="**/*.java"
07.
destdir="${build.classes}"
08.
debug="${javac.debug}"
09.
deprecation="${javac.deprecation}"
10.
includeantruntime="on">
11.
<classpath refid="classpath"/>
12.
</javac>
13.
</target>
(3).在<path id="classpath">中添加：<path refid="hadoop-jars"/>，效果如下：

view sourceprint?
1.
<!-- Override classpath to include Eclipse SDK jars -->
2.
<path id="classpath">
3.
<pathelement location="${build.classes}"/>
4.
<pathelement location="${hadoop.root}/build/classes"/>
5.
<path refid="eclipse-sdk-jars"/>
6.
<path refid="hadoop-jars"/>
7.
</path>
(4).在<target name="jar" depends="compile" unless="skip.contrib">这个标签里，在< file="${hadoop.root}/build/ivy/lib/Hadoop/common/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/>这个配置的下面添加如下几个jar包的配置：

view sourceprint?
1.
< file="${hadoop.root}/lib/commons-configuration-1.6.jar" todir="${build.dir}/lib" verbose="true"/>
2.
< file="${hadoop.root}/lib/commons-httpclient-3.0.1.jar" todir="${build.dir}/lib" verbose="true"/>
3.
< file="${hadoop.root}/lib/commons-lang-2.4.jar" todir="${build.dir}/lib" verbose="true"/>
4.
< file="${hadoop.root}/lib/jackson-core-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
5.
< file="${hadoop.root}/lib/jackson-mapper-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
最终效果如图：

view sourceprint?
01.
<!-- Override jar target to specify manifest -->
02.
<target name="jar" depends="compile" unless="skip.contrib">
03.
<mkdir dir="${build.dir}/lib"/>
04.
< file="${hadoop.root}/build/hadoop-core-${version}.jar" tofile="${build.dir}/lib/hadoop-core-1.0.1.jar" verbose="true"/>
05.
< file="${hadoop.root}/build/ivy/lib/Hadoop/common/commons-cli-${commons-cli.version}.jar" todir="${build.dir}/lib" verbose="true"/>
06.

07.
< file="${hadoop.root}/lib/commons-configuration-1.6.jar" todir="${build.dir}/lib" verbose="true"/>
08.
< file="${hadoop.root}/lib/commons-httpclient-3.0.1.jar" todir="${build.dir}/lib" verbose="true"/>
09.
< file="${hadoop.root}/lib/commons-lang-2.4.jar" todir="${build.dir}/lib" verbose="true"/>
10.
< file="${hadoop.root}/lib/jackson-core-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
11.
< file="${hadoop.root}/lib/jackson-mapper-asl-1.8.8.jar" todir="${build.dir}/lib" verbose="true"/>
12.

13.
<jar
14.
jarfile="${build.dir}/hadoop-${name}-${version}.jar"
15.
manifest="${root}/META-INF/MANIFEST.MF">
16.
<fileset dir="${build.dir}" includes="classes/ lib/"/>
17.
<fileset dir="${root}" includes="resources/ plugin.xml"/>
18.
</jar>
19.
</target>
(5).在文件末尾</project>标签之前添加配置：

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1.
<path id="hadoop-jars">
2.
<fileset dir="${hadoop.root}/">
3.
<include name="hadoop-*.jar"/>
4.
</fileset>
5.
</path>
5.打开hadoop-1.0.1的解压缩目录(我的是D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1)，复制两个jar包到对应的目录文件夹，以我的文件目录结构举例如下：

(1).将D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1\hadoop-core-1.0.1.jar 复制到D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1\build\这个文件夹中

(2).将D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1\lib\commons-cli-1.2.jar复制到D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1\build\ivy\lib\Hadoop\common这个文件夹中

6.再回到eclipse，打开项目中的\META-INF\MANIFEST.MF文件，做如下的添加：

view sourceprint?
1.
Bundle-ClassPath: classes/,
2.
lib/hadoop-core-1.0.1.jar,
3.
lib/commons-cli-1.2.jar,
4.
lib/commons-configuration-1.6.jar,
5.
lib/commons-httpclient-3.0.1.jar,
6.
lib/commons-lang-2.4.jar,
7.
lib/jackson-core-asl-1.8.8.jar,
8.
lib/jackson-mapper-asl-1.8.8.ja,
7.经过上边的配置，基本已经完成，我们可以编译项目了。右击build.xml文件选择 Run As Ant Build，编译成功，生成的hadoop-1.0.1-eclipse-plugin.jar在hadoop-1.0.1解压目录的\build\contrib\eclipse-plugin文件夹里面。

第四步，当然就是在eclipse中配置我们编译好的插件。

1.把hadoop-1.0.1-eclipse-plugin.jar文件放到eclipse安装目录的plugins中，重启eclipse。重启后，会在Window->Open Perspective->Other里，看到大象图标的Map/Rece出现，或者是window->Preferences中看到Hadoop Map/Rece这个选项。

2.window->Preferences中点击Hadoop Map/Rece这个选项，将Hadoop的那个解压缩目录(我的是D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1)的路径配置上，配置效果图如下：

\

3.然后我们在Window->Open Perspective->Other里，点击Map/Rece,切换到这个模式，截图如下：

\

4.切换到Map/Rece模式后，我们看到画面(4)中的截图，点击右下角的两个小图标，测试有没有反应，如果有反应，暂时先别配置，这个我下篇博客会具体讲。如果怎么点都没有反应，则可以做如下操作：

(1).打开项目中的\META-INF\MANIFEST.MF文件，找到之前编译时，添加的Bundle-ClassPath: classes/ 这个位置，之前我们添加了7个jar包的配置，再增加四个，如下：

view sourceprint?
1.
lib/hadoop-common-0.21.0.jar,
2.
lib/hadoop-hdfs-0.21.0.jar,
3.
lib/log4j-1.2.15.jar,
4.
lib/hadoop-mapred-0.21.0.jar
(2).然后我们还需要去网上下载这四个jar包放到下面的文件夹中，以我的目录举例：D:\SettingUp\ITSettingUp\Hadoop\hadoop-1.0\hadoop-1.0.1\lib。

(3).然后在重新编译即可，在替换原来的插件时，在重启eclipse的过程中，你可以这样做：先删除原来的插件，原来重启eclipse，确认Map/Rece没了；然后再关掉eclipse，将新的插件放到plugins里，之后再次启动eclipse。解决这个问题时我在网上参考的文章是：http://blog.csdn.net/kky2010_110/article/details/7774747，大家也可以看看~。

(4).上边所提到的截图如下：

\

经过上边说的这些步骤，eclipse中的hadoop插件我们算是编译完了，这个过程中一定要注意的是，不要怕失败，多尝试，因为hadoop版本与eclipse版本是有关系的，所以导致你的版本和我的不太一致，可能会失败，但是也可能会成功。所以在这里再次提醒，注意文章开始，我对自己的环境的版本的介绍，尤其是eclipse和hadoop的版本。建议大家如果有时间的话，可以先不管版本，按照我的步骤先走一遍，如果实在是不成功的话，则可以找个和我一样的eclipse和hadoop版本，再体验一回。因为，我在这个过程中，就发现，由于是第一次学hadoop，不见到成功的效果，总觉得少点什么，总想见识一下，莫取笑哈~

至于下一步，如果配置Location和运行WordCount，我会在下一篇博客中具体说明，谢谢支持，觉得文章还不错的话，多多点赞，多多留言哈，这将使我充满动力!

D. hadoop 2.8.2 怎么编译

在不使用eclipse情况使java程序在hadoop
2.2中运行的完整过程。整个过程中其实分为java程序的编译，生成jar包，运行测试。
这三个步骤运用的命令都比较简单，主要的还是如何找到hadoop
2.2提供给java程序用来编译的jar包。具体可以查看:
HADOOP_HOME/share/hadoop/httpfs/tomcat/webapps/webhdfs/WEB-INF/lib目录
下面会通过一个在hadoop中创建一个目录的JAVA例子来进行演示
具体代码如下：
package
com.wan.demo;
import
java.io.IOException;
import
org.apache.hadoop.conf.Configuration;
import
org.apache.hadoop.fs.FileSystem;
import
org.apache.hadoop.fs.Path;
public
class
HADemo
{
public
static
void
main(String[]
args)
{
//
TODO
Auto-generated
method
stub
mkdir(args[0]);
}
public
static
void
mkdir(String
dir){
Configuration
configuration=new
Configuration();
FileSystem
fs;
try
{
fs
=
FileSystem.get(configuration);
fs.mkdirs(new
Path(dir));
fs.close();
}
catch
(IOException
e)
{
//
TODO
Auto-generated
catch
block
e.printStackTrace();
}
}
}
把HADemo.java文件拷贝到linux环境中
配置HADOOP_HOME/bin到环境中，启动集群，进入HADemo.java文件目录中
注:下面的lib目录里面的文件由HADOOP_HOME/share/hadoop/httpfs/tomcat/webapps/
webhdfs/WEB-INF/lib目录中获取，下面做的目的是为了缩减命令长度
1.编译java
#
mkdir
class
#Javac
-classpath
.:lib/hadoop-common-2.2.0.jar:lib/hadoop-annotations-2.2.0.jar
-d
class
HADemo.java
2.生成jar包
#jar
-cvf
hademo.jar
-C
class/
.
added
manifest
adding:
com/(in
=
0)
(out=
0)(stored
0%)
adding:
com/wan/(in
=
0)
(out=
0)(stored
0%)
adding:
com/wan/demo/(in
=
0)
(out=
0)(stored
0%)
adding:
com/wan/demo/HADemo.class(in
=
844)
(out=
520)(deflated
38%)
3.测试运行
#hadoop
jar
hademo.jar
com.wan.demo.HADemo
/test
检测：
#hadoop
fs
-ls
/