从零教你如何获取hadoop2.4源码并使用eclipse关联hadoop2.4源码

问题导读:
1.如何通过官网src包,获取hadoop的全部代码
2.通过什么样的操作,可以查看hadoop某个函数或则类的实现?
3.maven的作用是什么?






我们如果想搞开发,研究源码对我们的帮助很大。不明白原理就如同黑盒子,遇到问题,我们也摸不着思路。所以这里交给大家
一.如何获取源码
二.如何关联源码

一.如何获取源码

1.下载hadoop的maven程序包

(1)官网下载
这里我们先从官网上下载maven包hadoop-2.4.0-src.tar.gz。
官网下载地址

对于不知道怎么去官网下载,可以查看:新手指导:hadoop官网介绍及如何下载hadoop(2.4)各个版本与查看hadoop API介绍

(2)网盘下载
也可以从网盘下载:
http://pan.baidu.com/s/1kToPuGB

2.通过maven获取源码
获取源码的方式有两种,一种是通过命令行的方式,一种是通过eclipse。这里主要讲通过命令的方式

通过命令的方式获取源码:
1.解压包

<ignore_js_op> 


解压包的时候遇到了下面问题。不过不用管,我们继续往下走

1        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-applicationhistoryservice\target\classes\org\apache\hadoop\yarn\server\applicationhistoryservice\ApplicationHistoryClientService$ApplicationHSClientProtocolHandler.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
2        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-applicationhistoryservice\target\classes\org\apache\hadoop\yarn\server\applicationhistoryservice\timeline\LeveldbTimelineStore$LockMap$CountingReentrantLock.class:系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
3        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-applicationhistoryservice\target\test-classes\org\apache\hadoop\yarn\server\applicationhistoryservice\webapp\TestAHSWebApp$MockApplicationHistoryManagerImpl.class:系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
4        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\monitor\capacity\TestProportionalCapacityPreemptionPolicy$IsPreemptionRequestFor.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
5        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\recovery\TestFSRMStateStore$TestFSRMStateStoreTester$TestFileSystemRMStore.class:系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
6        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\recovery\TestZKRMStateStore$TestZKRMStateStoreTester$TestZKRMStateStoreInternal.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
7        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\recovery\TestZKRMStateStoreZKClientConnections$TestZKClient$TestForwardingWatcher.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
8        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\recovery\TestZKRMStateStoreZKClientConnections$TestZKClient$TestZKRMStateStore.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip
9        : 无法创建文件:D:\hadoop2\hadoop-2.4.0-src\hadoop-yarn-project\hadoop-yarn\hadoop-yarn-server\hadoop-yarn-server-resourcemanager\target\test-classes\org\apache\hadoop\yarn\server\resourcemanager\rmapp\attempt\TestRMAppAttemptTransitions$TestApplicationAttemptEventDispatcher.class:
路径和文件名总长度不能超过260个字符
系统找不到指定的路径。        D:\hadoop2\hadoop-2.4.0-src.zip



2.通过maven获取源码

这里需要说明的是,在使用maven的时候,需要先安装jdk,protoc ,如果没有安装可以参考win7如何安装maven、安装protoc

(1)进入hadoop-2.4.0-src\hadoop-maven-plugins,运行mvn install

  1. D:\hadoop2\hadoop-2.4.0-src\hadoop-maven-plugins>mvn install
复制代码



显示如下信息

  1. [INFO] Scanning for projects...
  2. [WARNING]
  3. [WARNING] Some problems were encountered while building the effective model for
  4. org.apache.hadoop:hadoop-maven-plugins:maven-plugin:2.4.0
  5. [WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found d
  6. uplicate declaration of plugin org.apache.maven.plugins:maven-enforcer-plugin @
  7. org.apache.hadoop:hadoop-project:2.4.0, D:\hadoop2\hadoop-2.4.0-src\hadoop-proje
  8. ct\pom.xml, line 1015, column 15
  9. [WARNING]
  10. [WARNING] It is highly recommended to fix these problems because they threaten t
  11. he stability of your build.
  12. [WARNING]
  13. [WARNING] For this reason, future Maven versions might no longer support buildin
  14. g such malformed projects.
  15. [WARNING]
  16. [INFO]
  17. [INFO] Using the builder org.apache.maven.lifecycle.internal.builder.singlethrea
  18. ded.SingleThreadedBuilder with a thread count of 1
  19. [INFO]
  20. [INFO] ------------------------------------------------------------------------
  21. [INFO] Building Apache Hadoop Maven Plugins 2.4.0
  22. [INFO] ------------------------------------------------------------------------
  23. [INFO]
  24. [INFO] --- maven-antrun-plugin:1.7:run (create-testdirs) @ hadoop-maven-plugins
  25. ---
  26. [INFO] Executing tasks
  27. main:
  28. [INFO] Executed tasks
  29. [INFO]
  30. [INFO] --- maven-plugin-plugin:3.0:descriptor (default-descriptor) @ hadoop-mave
  31. n-plugins ---
  32. [INFO] Using 'UTF-8' encoding to read mojo metadata.
  33. [INFO] Applying mojo extractor for language: java-annotations
  34. [INFO] Mojo extractor for language: java-annotations found 2 mojo descriptors.
  35. [INFO] Applying mojo extractor for language: java
  36. [INFO] Mojo extractor for language: java found 0 mojo descriptors.
  37. [INFO] Applying mojo extractor for language: bsh
  38. [INFO] Mojo extractor for language: bsh found 0 mojo descriptors.
  39. [INFO]
  40. [INFO] --- maven-resources-plugin:2.2:resources (default-resources) @ hadoop-mav
  41. en-plugins ---
  42. [INFO] Using default encoding to copy filtered resources.
  43. [INFO]
  44. [INFO] --- maven-compiler-plugin:2.5.1:compile (default-compile) @ hadoop-maven-
  45. plugins ---
  46. [INFO] Nothing to compile - all classes are up to date
  47. [INFO]
  48. [INFO] --- maven-plugin-plugin:3.0:descriptor (mojo-descriptor) @ hadoop-maven-p
  49. lugins ---
  50. [INFO] Using 'UTF-8' encoding to read mojo metadata.
  51. [INFO] Applying mojo extractor for language: java-annotations
  52. [INFO] Mojo extractor for language: java-annotations found 2 mojo descriptors.
  53. [INFO] Applying mojo extractor for language: java
  54. [INFO] Mojo extractor for language: java found 0 mojo descriptors.
  55. [INFO] Applying mojo extractor for language: bsh
  56. [INFO] Mojo extractor for language: bsh found 0 mojo descriptors.
  57. [INFO]
  58. [INFO] --- maven-resources-plugin:2.2:testResources (default-testResources) @ ha
  59. doop-maven-plugins ---
  60. [INFO] Using default encoding to copy filtered resources.
  61. [INFO]
  62. [INFO] --- maven-compiler-plugin:2.5.1:testCompile (default-testCompile) @ hadoo
  63. p-maven-plugins ---
  64. [INFO] No sources to compile
  65. [INFO]
  66. [INFO] --- maven-surefire-plugin:2.16:test (default-test) @ hadoop-maven-plugins
  67. ---
  68. [INFO] No tests to run.
  69. [INFO]
  70. [INFO] --- maven-jar-plugin:2.3.1:jar (default-jar) @ hadoop-maven-plugins ---
  71. [INFO] Building jar: D:\hadoop2\hadoop-2.4.0-src\hadoop-maven-plugins\target\had
  72. oop-maven-plugins-2.4.0.jar
  73. [INFO]
  74. [INFO] --- maven-plugin-plugin:3.0:addPluginArtifactMetadata (default-addPluginA
  75. rtifactMetadata) @ hadoop-maven-plugins ---
  76. [INFO]
  77. [INFO] --- maven-site-plugin:3.3:attach-descriptor (attach-descriptor) @ hadoop-
  78. maven-plugins ---
  79. [INFO]
  80. [INFO] --- maven-install-plugin:2.3.1:install (default-install) @ hadoop-maven-p
  81. lugins ---
  82. [INFO] Installing D:\hadoop2\hadoop-2.4.0-src\hadoop-maven-plugins\target\hadoop
  83. -maven-plugins-2.4.0.jar to C:\Users\hyj\.m2\repository\org\apache\hadoop\hadoop
  84. -maven-plugins\2.4.0\hadoop-maven-plugins-2.4.0.jar
  85. [INFO] Installing D:\hadoop2\hadoop-2.4.0-src\hadoop-maven-plugins\pom.xml to C:
  86. \Users\hyj\.m2\repository\org\apache\hadoop\hadoop-maven-plugins\2.4.0\hadoop-ma
  87. ven-plugins-2.4.0.pom
  88. [INFO] ------------------------------------------------------------------------
  89. [INFO] BUILD SUCCESS
  90. [INFO] ------------------------------------------------------------------------
  91. [INFO] Total time: 4.891 s
  92. [INFO] Finished at: 2014-06-23T14:47:33+08:00
  93. [INFO] Final Memory: 21M/347M
  94. [INFO] ------------------------------------------------------------------------
复制代码


部分截图如下:

<ignore_js_op> 


<ignore_js_op> 



(2)运行

  1. mvn eclipse:eclipse -DskipTests
复制代码

这时候注意,我们进入的是hadoop_home,我这里是D:\hadoop2\hadoop-2.4.0-src

部分信息如下

  1. [INFO]
  2. [INFO] ------------------------------------------------------------------------
  3. [INFO] Reactor Summary:
  4. [INFO]
  5. [INFO] Apache Hadoop Main ................................ SUCCESS [  0.684 s]
  6. [INFO] Apache Hadoop Project POM ......................... SUCCESS [  0.720 s]
  7. [INFO] Apache Hadoop Annotations ......................... SUCCESS [  0.276 s]
  8. [INFO] Apache Hadoop Project Dist POM .................... SUCCESS [  0.179 s]
  9. [INFO] Apache Hadoop Assemblies .......................... SUCCESS [  0.121 s]
  10. [INFO] Apache Hadoop Maven Plugins ....................... SUCCESS [  1.680 s]
  11. [INFO] Apache Hadoop MiniKDC ............................. SUCCESS [  1.802 s]
  12. [INFO] Apache Hadoop Auth ................................ SUCCESS [  1.024 s]
  13. [INFO] Apache Hadoop Auth Examples ....................... SUCCESS [  0.160 s]
  14. [INFO] Apache Hadoop Common .............................. SUCCESS [  1.061 s]
  15. [INFO] Apache Hadoop NFS ................................. SUCCESS [  0.489 s]
  16. [INFO] Apache Hadoop Common Project ...................... SUCCESS [  0.056 s]
  17. [INFO] Apache Hadoop HDFS ................................ SUCCESS [  2.770 s]
  18. [INFO] Apache Hadoop HttpFS .............................. SUCCESS [  0.965 s]
  19. [INFO] Apache Hadoop HDFS BookKeeper Journal ............. SUCCESS [  0.629 s]
  20. [INFO] Apache Hadoop HDFS-NFS ............................ SUCCESS [  0.284 s]
  21. [INFO] Apache Hadoop HDFS Project ........................ SUCCESS [  0.061 s]
  22. [INFO] hadoop-yarn ....................................... SUCCESS [  0.052 s]
  23. [INFO] hadoop-yarn-api ................................... SUCCESS [  0.842 s]
  24. [INFO] hadoop-yarn-common ................................ SUCCESS [  0.322 s]
  25. [INFO] hadoop-yarn-server ................................ SUCCESS [  0.065 s]
  26. [INFO] hadoop-yarn-server-common ......................... SUCCESS [  0.972 s]
  27. [INFO] hadoop-yarn-server-nodemanager .................... SUCCESS [  0.580 s]
  28. [INFO] hadoop-yarn-server-web-proxy ...................... SUCCESS [  0.379 s]
  29. [INFO] hadoop-yarn-server-applicationhistoryservice ...... SUCCESS [  0.281 s]
  30. [INFO] hadoop-yarn-server-resourcemanager ................ SUCCESS [  0.378 s]
  31. [INFO] hadoop-yarn-server-tests .......................... SUCCESS [  0.534 s]
  32. [INFO] hadoop-yarn-client ................................ SUCCESS [  0.307 s]
  33. [INFO] hadoop-yarn-applications .......................... SUCCESS [  0.050 s]
  34. [INFO] hadoop-yarn-applications-distributedshell ......... SUCCESS [  0.202 s]
  35. [INFO] hadoop-yarn-applications-unmanaged-am-launcher .... SUCCESS [  0.194 s]
  36. [INFO] hadoop-yarn-site .................................. SUCCESS [  0.057 s]
  37. [INFO] hadoop-yarn-project ............................... SUCCESS [  0.066 s]
  38. [INFO] hadoop-mapreduce-client ........................... SUCCESS [  0.091 s]
  39. [INFO] hadoop-mapreduce-client-core ...................... SUCCESS [  1.321 s]
  40. [INFO] hadoop-mapreduce-client-common .................... SUCCESS [  0.786 s]
  41. [INFO] hadoop-mapreduce-client-shuffle ................... SUCCESS [  0.456 s]
  42. [INFO] hadoop-mapreduce-client-app ....................... SUCCESS [  0.508 s]
  43. [INFO] hadoop-mapreduce-client-hs ........................ SUCCESS [  0.834 s]
  44. [INFO] hadoop-mapreduce-client-jobclient ................. SUCCESS [  0.541 s]
  45. [INFO] hadoop-mapreduce-client-hs-plugins ................ SUCCESS [  0.284 s]
  46. [INFO] Apache Hadoop MapReduce Examples .................. SUCCESS [  0.851 s]
  47. [INFO] hadoop-mapreduce .................................. SUCCESS [  0.099 s]
  48. [INFO] Apache Hadoop MapReduce Streaming ................. SUCCESS [  0.742 s]
  49. [INFO] Apache Hadoop Distributed Copy .................... SUCCESS [  0.335 s]
  50. [INFO] Apache Hadoop Archives ............................ SUCCESS [  0.397 s]
  51. [INFO] Apache Hadoop Rumen ............................... SUCCESS [  0.371 s]
  52. [INFO] Apache Hadoop Gridmix ............................. SUCCESS [  0.230 s]
  53. [INFO] Apache Hadoop Data Join ........................... SUCCESS [  0.184 s]
  54. [INFO] Apache Hadoop Extras .............................. SUCCESS [  0.217 s]
  55. [INFO] Apache Hadoop Pipes ............................... SUCCESS [  0.048 s]
  56. [INFO] Apache Hadoop OpenStack support ................... SUCCESS [  0.244 s]
  57. [INFO] Apache Hadoop Client .............................. SUCCESS [  0.590 s]
  58. [INFO] Apache Hadoop Mini-Cluster ........................ SUCCESS [  0.230 s]
  59. [INFO] Apache Hadoop Scheduler Load Simulator ............ SUCCESS [  0.650 s]
  60. [INFO] Apache Hadoop Tools Dist .......................... SUCCESS [  0.334 s]
  61. [INFO] Apache Hadoop Tools ............................... SUCCESS [  0.042 s]
  62. [INFO] Apache Hadoop Distribution ........................ SUCCESS [  0.144 s]
  63. [INFO] ------------------------------------------------------------------------
  64. [INFO] BUILD SUCCESS
  65. [INFO] ------------------------------------------------------------------------
  66. [INFO] Total time: 31.234 s
  67. [INFO] Finished at: 2014-06-23T14:55:08+08:00
  68. [INFO] Final Memory: 84M/759M
  69. [INFO] ------------------------------------------------------------------------
复制代码

这时候,我们已经把源码给下载下来了。这时候,我们会看到文件会明显增大。


<ignore_js_op> 



3.关联eclipse源码

加入我们以下程序
<ignore_js_op> hadoop2.2mapreduce例子.rar (1.14 MB, 下载次数: 400, 售价: 1 云币) 
如下图示,对他们进行了打包
<ignore_js_op> 

这两个文件, MaxTemperature.zip为mapreduce例子,mockito-core-1.8.5.jar为mapreduce例子所引用的包
这里需要说明的是,mapreduce为2.2,但是不影响关联源码,只是交给大家该如何关联源码
我们解压之后,导入eclipse
(对于导入项目不熟悉,参考零基础教你如何导入eclipse项目

<ignore_js_op> 


我们导入之后,看到很多的红线,这些其实都是没有引用包,下面我们开始解决这些语法问题。
一、解决导入jar包
(1)引入mockito-core-1.8.5.jar

(2)hadoop2.4编译包中的jar文件,这些文件的位置如下:

hadoop_home中share\hadoop文件夹下,具体我这的位置D:\hadoop2\hadoop-2.4.0\share\hadoop
找到里面的jar包,举例如下:lib文件中的jar包,以及下面的jar包都添加到buildpath中。
如果对于引用包,不知道该如何添加这些jar包,参考hadoop开发方式总结及操作指导
注意的是,我们这里是引入的是编译包,编译的下载hadoop--642.4.0.tar.gz
链接: http://pan.baidu.com/s/1c0vPjG0 密码:xj6l)


更多包下载可以参考hadoop家族、strom、spark、Linux、flume等jar包、安装包汇总下载

<ignore_js_op> 



<ignore_js_op> 


二、关联源码
1.我们导入jar包之后,就没有错误了,如下图所示

<ignore_js_op> 

2.找不到源码

当我们想看一个类或则函数怎么实现的时候,通过Open Call Hierarchy,却找不到源文件。

<ignore_js_op> 



<ignore_js_op> 


3.Attach Source

<ignore_js_op> 

上面三处,我们按照顺序添加即可,我们选定压缩包之后,单击确定,ok了,我们的工作已经完毕。

注意:对于hadoop-2.2.0-src.zip则是我们上面通过maven下载的源码,然后压缩的文件,记得一定是压缩文件zip的形式


4.验证关联后查看源码

我们再次执行上面操作,通过Open Call Hierarchy




看到下面内容



<ignore_js_op> 


然后我们双击上图主类,即红字部分,我们看到下面内容:

<ignore_js_op> 


问题:
细心的同学,这里面我们产生一个问题,因为我们看到的是.class文件,而不是.java文件。那么他会不会和我们所看到的.java文件不一样那。
其实是一样的,感兴趣的同学,可以验证一下。

posted @ 2016-08-17 12:03  哼哼哈哈二将  阅读(2037)  评论(0编辑  收藏  举报