Setup Java Development Environment In Ubuntu(11.10)

How to setup java development environment in the ubuntu(11.10)?

here are some steps:

1. Choose a version of java and download it from the Oracle
   
   I choose the jdk_1.7.0_03 here, and download it into ~/Downloads/
2. Extract and install it.
   点击(此处)折叠或打开

   sudo tar zxvf ~/Downloads/jdk-7u3-linux-i586.tar.gz  -C /usr/lib/jvm
   #Note please:#you can change the name of jdk,#BUT CAN'T create a symbolic link to it otherwise the you will get error message like below:
   ray@ray-laptop:~$ ls -l /usr/lib/jvm/total 4lrwxrwxrwx 1 ray ray   12 2012-04-21 15:57 java_7_sun -> jdk1.7.0_03/drwxr-xr-x 8 ray ray 4096 2012-01-21 02:37 jdk1.7.0_03
   ray@ray-laptop:~$ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/java-7-sun/bin/java 300update-alternatives: error: alternative path /usr/lib/jvm/java-7-sun/bin/java doesn't exist.
   ray@ray-laptop:~$ ls -l /usr/lib/jvm/java_7_sun/bin/java-rwxr-xr-x 1 ray ray 5654 2012-01-21 02:27 /usr/lib/jvm/java_7_sun/bin/java
   

3. Modify your Environment
   点击(此处)折叠或打开

   vim ~/.bashrc
   
   export JAVA_HOME=/usr/lib/jvm/jdk_1.7.0_03
   export JRE_HOME=${JAVA_HOME}/jre
   export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
   export PATH=${JAVA_HOME}/bin:$PATH
   
   #and then save it.

4. Config the default java in your system:
   

   sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk_1.7.0_03/bin/java 300
   sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk_1.7.0_03/bin/javac 300
   sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk_1.7.0_03/bin/jar 300
   df
   sudo update-alternatives --config java
   #and then follow the promotion and take your choice.#Here is my output of this command:"There is only one alternative in link group java: /usr/lib/jvm/jdk_1.7.0_03/bin/javaNothing to configure."

   
   
5. Check your java now: 

ray@ray-laptop:~$ java -version
java version "1.7.0_03"
Java(TM) SE Runtime Environment (build 1.7.0_03-b04)
Java HotSpot(TM) Client VM (build 22.1-b02, mixed mode)

Reference:

1.Ubuntu 11.04 下安装配置 JDK 7

http://blog.csdn.net/yang_hui1986527/article/details/6677450