【轉】http://blog.csdn.net/lipengshuai0507/article/details/17020131
1.首先下載最新版 jdk 64-bit版 (jdk-7u45-linux-x64.tar.gz)
從官網下載http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html
2.將jdk-7u45-linux-x64.tar.gz拷貝到/usr/lib/jvm/目錄下面,這里如果沒有jdk文件夾,則創建該文件夾,命令:
sudo mkdir jvm //創建文件夾jdk
sudo cp -r ~/download/jdk-7u45-linux-x64.tar.gz /usr/lib/jvm/ //把下載的文件拷貝到新創建的目錄下面
sudo tar -zxvg jdk-7u45-linux-x64.tar.gz //解壓縮文件
3.設置環境變量,用nano打開/etc/profile文件
sudo nano /etc/profile
在文件的最后面增加:
export JAVA_HOME=/usr/lib/jvm/jdk1.7.0_45
export JRE_HOME=/usr/lib/jvm/jdk1.7.0_45/jre
export PATH=$JAVA_HOME/bin:$JAVA_HOME/jre/bin:$PATH
export CLASSPATH=$CLASSPATH:.:$JAVA_HOME/lib:$JAVA_HOME/jre/lib
4.將系統默認的jdk修改過來
$ sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_45/bin/java 300
$ sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0_45/bin/javac 300
$ sudo update-alternatives --config java
$ sudo update-alternatives --config javac
5.檢測,輸入java -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)