ubuntu下安装java和eclipse

java安装
1 下载jdk
http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html
2 切换到root用户
sudosu
3 进入目录
cd/usr/local/lib
4 解压下载的压缩文件
tar-zxvf /home/linger/toInstall/jdk-7u55-linux-x64.tar.gz
5 配置环境变量
打开文件gedit/etc/profile
在/etc/profile文件末尾加上如下的三行代码:
exportJAVA_HOME=/usr/local/lib/jdk1.7.0_55
exportCLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
exportPATH=$PATH:$JAVA_HOME/bin
6 chown root:root -R /usr/local/lib/jdk1.7.0_55
7 chmod 755 -R /usr/local/lib/jdk1.7.0_55
8 source /etc/profile
9 java -version

eclipse
1 下载eclipse
http://www.eclipse.org/downloads/
2 进入目录
cd/usr/local
3 解压到当前目录
tar-zxvf/home/linger/toInstall/eclipse-standard-kepler-SR2-linux-gtk-x86_64.tar.gz
4 如果java环境安装好就可以使用了
具体参考：http://blog.csdn.net/gavin_dinggengjia/article/details/7364375