在Eclipse中导入hadoop

0. 准备
(1) 需要有gcc、autoconf、automake来编译安装google的protocol buffer

http://code.google.com/p/protobuf/downloads/list
(2) http://protobuf.googlecode.com/files/protobuf-2.4.1.tar.gz
./configure --prefix=/usr/local
make
make check
sudo make install
完成后，检验
$ protoc
Missing input file.
(3) JDK、ANT、Maven(MVN)

1. 在Eclipse中增加SVN插件
在help->install new software
添加 http://subclipse.tigris.org/update/

在window/Open Perspective中就会右SVN的视图

 

2. 导出代码(该trunk下面右多个project)

svn checkout http://svn.apache.org/repos/asf/hadoop/common/trunk/ hadoop-trunk

 

3. mvn: build the code to get it ready for importing into Eclipse.

cd haoop-trunk
$ mvn install -DskipTests
$ mvn eclipse:eclipse -DdownloadSources=true -DdownloadJavadocs=true
Note: This may take a while the first time, 
as all libraries are fetched from the internet, and the whole build is performed
error：
Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2:exec (compile-proto) 
on project hadoop-common: Command execution failed. Cannot run program "protoc"
issue:  install google's protocol buffer


4. In Eclipse
After the above, do the following to finally have projects in Eclipse ready and waiting for you to go on that scratch-itching development spree:

For Common
File -> Import...
Choose "Existing Projects into Workspace"
Select the hadoop-common-project directory as the root directory
Select the hadoop-annotations, hadoop-auth, hadoop-auth-examples and hadoop-common projects
Click "Finish"
File -> Import...
Choose "Existing Projects into Workspace"
Select the hadoop-assemblies directory as the root directory
Select the hadoop-assemblies project
Click "Finish"
To get the projects to build cleanly:
* Add target/generated-test-sources/java as a source directory for hadoop-common
* You may have to add then remove the JRE System Library to avoid errors due to access restrictions


For HDFS
File -> Import...
Choose "Existing Projects into Workspace"
Select the hadoop-hdfs-project directory as the root directory
Select the hadoop-hdfs project
Click "Finish"


For MapReduce
File -> Import...
Choose "Existing Projects into Workspace"
Select the hadoop-mapreduce-project directory as the root directory
Select the hadoop-mapreduce-project project
Click "Finish"
Note: in the case of MapReduce the testjar package is broken. This is expected since it is a part of a testcase that checks for incorrect packaging. This is not to be worried about.


To run tests from Eclipse you need to additionally do the following:
Under project Properties, select Java Build Path, and the Libraries tab
Click "Add External Class Folder" and select the build directory of the current project