使用update-alternatives切換ubuntu下預設java命令

使用update-alternatives切換ubuntu下預設java命令

sky@sky-VGN-CR23-B:~$ cd /usr/java/jdk1.7.0_21/

sky@sky-VGN-CR23-B:/usr/java/jdk1.7.0_21$ cd ..

sky@sky-VGN-CR23-B:/usr/java$ sudo ln -s ./jdk1.7.0_21 ./jdk1.7


sky@sky-VGN-CR23-B:/usr/java$ sudo rm jdk-7u21-linux-i586.tar.gz


sky@sky-VGN-CR23-B:/usr/java$ sudo update-alternatives --install /usr/bin/java java /usr/java/jdk1.7/bin/java 1
update-alternatives: using /usr/java/jdk1.7/bin/java to provide /usr/bin/java (java) in 自動模式

sky@sky-VGN-CR23-B:/usr/java$ sudo update-alternatives --config java
There is only one alternative in link group java (providing /usr/bin/java): /usr/java/jdk1.7/bin/java
無需配置。

sky@sky-VGN-CR23-B:/usr/java$ java -version
java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
Java HotSpot(TM) Server VM (build 23.21-b01, mixed mode)


sky@sky-VGN-CR23-B:/usr/java$ ll /usr/bin/java
lrwxrwxrwx 1 root root 22  4月 27 01:23 /usr/bin/java -> /etc/alternatives/java*

sky@sky-VGN-CR23-B:/usr/java$ ll /etc/alternatives/java
lrwxrwxrwx 1 root root 25  4月 27 01:23 /etc/alternatives/java -> /usr/java/jdk1.7/bin/java*

sky@sky-VGN-CR23-B:/usr/java$ ll /usr/java/jdk1.7
lrwxrwxrwx 1 root root 13  4月 27 01:14 /usr/java/jdk1.7 -> ./jdk1.7.0_21/