写了个shell脚本自由切换openjdk7和openjdk8

来源：互联网发布：mac有没有助手编辑：程序博客网时间：2024/06/14 14:16

1、脚本演示

xcz@xcz-OptiPlex-3020:~$
xcz@xcz-OptiPlex-3020:~$ switch_jdk.sh
0
usage:
switch_jdk.sh java_version(7 or 8)
---------------------------------------------------
Now is at:
openjdk version "1.8.0_111"
OpenJDK Runtime Environment (build 1.8.0_111-8u111-b14-3~12.04-b14)
OpenJDK 64-Bit Server VM (build 25.111-b14, mixed mode)
javac 1.8.0_111
xcz@xcz-OptiPlex-3020:~$
xcz@xcz-OptiPlex-3020:~$
xcz@xcz-OptiPlex-3020:~$ switch_jdk.sh 7
switch to java 7...
spawn sudo update-alternatives --config java
[sudo] password for xcz:

There are 2 choices for the alternative java (providing /usr/bin/java).

Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1069 auto mode
1 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1051 manual mode
* 2 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1069 manual mode

Press enter to keep the current choice[*], or type selection number: 1
spawn sudo update-alternatives --config javac
[sudo] password for xcz:

There are 2 choices for the alternative javac (providing /usr/bin/javac).

Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-8-openjdk-amd64/bin/javac 1069 auto mode
1 /usr/lib/jvm/java-7-openjdk-amd64/bin/javac 1051 manual mode
* 2 /usr/lib/jvm/java-8-openjdk-amd64/bin/javac 1069 manual mode

Press enter to keep the current choice[*], or type selection number: 1
1
update-alternatives: using /usr/lib/jvm/java-7-openjdk-amd64/bin/javac to provide /usr/bin/javac (javac) in manual mode.
---------------------------------------------------
Now is at:
java version "1.7.0_91"
OpenJDK Runtime Environment (IcedTea 2.6.3) (7u91-2.6.3-0ubuntu0.12.04.1)
OpenJDK 64-Bit Server VM (build 24.91-b01, mixed mode)
javac 1.7.0_91
xcz@xcz-OptiPlex-3020:~$
xcz@xcz-OptiPlex-3020:~$
xcz@xcz-OptiPlex-3020:~$

2、需要用到下面2个脚本完成

脚本1：/home/xcz/bin/update-alternatives-exp.sh

#!/usr/bin/expectset VERSION [lindex $argv 0]set PASSWORD "123456"spawn sudo update-alternatives --config javaexpect {"assword" {send "$PASSWORD\n"send_user "\n"exp_continue}"selection number" {send "$VERSION\n"send_user "$VERSION\n"}}spawn sudo update-alternatives --config javacexpect {"assword" {send "$PASSWORD\n"send_user "\n"exp_continue}"selection number" {send "$VERSION\n"send_user "$VERSION\n"}}interact

脚本2：/home/xcz/bin/switch_jdk.sh

#!/bin/bashif [ $# -ne 1 ]thenecho $#echo "usage:"echo "switch_jdk.sh java_version(7 or 8)"echo "---------------------------------------------------"echo "Now is at:"java -versionjavac -versionexitfiif [ $1 = "version" ]thenjava -versionjavac -versionexitfiif [ $1 = "7" ]thenecho "switch to java 7..."/home/xcz/bin/update-alternatives-exp.sh 1elif [ $1 = "8" ]thenecho "switch to java 8..."/home/xcz/bin/update-alternatives-exp.sh 2elseecho "Warning: not found java version $1"exitfiecho "---------------------------------------------------"echo "Now is at:"java -versionjavac -version

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