JAVA JDK版本切換__JAVA

首先安裝sun1.6，這裡我安裝的目錄是/usr/java/jdk1.6.0_45

然後設定profile檔案/etc/profile(檔案的末尾添加該檔案)

sudo vim /etc/profile

export JAVA_HOME=/usr/java/jdk1.6.0_45export JRE_HOME=/usr/java/jdk1.6.0_45/jreexport CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jarexport PATH=$PATH:$JAVA_HOME/bin

source /etc/profile

然後安裝openjdk1.7，在software center中可以進行安裝，安裝完畢後執行如下命令：

gsc@gsc-250:~$ sudo update-alternatives --install /usr/bin/java java /usr/java/jdk1.6.0_45/bin/java 300gsc@gsc-250:~$ sudo update-alternatives --install /usr/bin/javac javac /usr/java/jdk1.6.0_45/bin/javac 300gsc@gsc-250:~$ sudo update-alternatives --install /usr/bin/javadoc javadoc /usr/java/jdk1.6.0_45/bin/javadoc 300gsc@gsc-250:~$ sudo update-alternatives --install /usr/bin/javap javap /usr/java/jdk1.6.0_45/bin/javap 300

使用如下命令切換：

gsc@gsc-250:~/my_carreer/webrtc-checkout$ sudo update-alternatives --config java There are 2 choices for the alternative java (providing /usr/bin/java).  Selection    Path                                            Priority   Status------------------------------------------------------------  0            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      auto mode  1            /usr/java/jdk1.6.0_45/bin/java                   300       manual mode* 2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manual modePress enter to keep the current choice[*], or type selection number: 查看當前java版本：<pre name="code" class="html">gsc@gsc-250:~/my_carreer/webrtc-checkout$ java -versionjava version "1.7.0_85"OpenJDK Runtime Environment (IcedTea 2.6.1) (7u85-2.6.1-5ubuntu0.14.04.1)OpenJDK 64-Bit Server VM (build 24.85-b03, mixed mode)

具體需要切換的工具如下：

 2045  sudo update-alternatives --config java    2046  sudo update-alternatives --config javac    2047  sudo update-alternatives --config javadoc 2048  sudo update-alternatives --config javap