一、mac
1、jdk查看路径:
$ /usr/libexec/java_home -V
2、环境变量:
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.7.0_80.jdk/Contents/Home
export PATH=$JAVA_HOME/bin:$PATH:.
export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar:.
3、卸载:
$ sudo rm -fr /Library/Internet Plug-Ins/JavaAppletPlugin.plugin
$ sudo rm -fr /Library/PreferencesPanes/JavaControlPanel.prefPane
$ sudo rm -fr ~/Library/Application Support/Java
$ sudo rm -rf /Library/Java/JavaVirtualMachines/jdk*****.jdk
4、jdk从老版本切换旧版本,出现mac弹窗问题
$ pkgutil --expand /Volumes/JDK 7 Update 51/JDK 7 Update 51.pkg /tmp/jdk.unpkg #find 中会挂载JDK 7 Update 51 ,注意反斜杠是转义空格,不正确不能成功执行命令
$ cd /tmp/jdk.unpkg
$ vim Distribution
## 将函数 pm_install_check 内容清空,直接返回true
function pm_install_check() {
return true;
}
$ pkgutil --flatten /tmp/jdk.unpkg /tmp/jdk.pkg #重新编译pkg,成功后会在/tmp下新增一个jdk.pkg 双击安装即可
二、linux
1、解压
tar -zxvf jdk-8u181-linux-x64.tar.gz -C /usr/local/java
2、环境变量
vim /etc/profile
3、末尾添加
export JAVA_HOME=/usr/local/java/jdk1.8.0_181
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$PATH:$JAVA_HOME/bin
4、使其生效
source /etc/profile
jdk1.6 安装
mkdir /usr/lib/java
chmod 777 jdk-6u41-linux-x64.bin
sudo ./jdk-6u41-linux-x64.bin
vim /etc/environment
JAVAHOME=/usr/lib/java/jdk1.6.0_45
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/java/jdk1.6.0_45/bin:/usr/lib/java/jdk1.6.0_45/jre/bin"
CLASSPATH=.:/usr/lib/java/jdk1.6.0_45/lib:/usr/lib/java/jdk1.6.0_45/jre/lib
source vim /etc/environment
java -version
三、windows
1、环境变量
CLASSPATH 添加 .;%JAVA_HOME%libdt.jar;%JAVA_HOME%lib ools.jar;
JAVA_HOME 添加 D:Javajdk1.8.0_101
path 追加 ;%JAVA_HOME%in;%JAVA_HOME%jrein;
四、Linux open jdk
# open jdk7
# 列出可安装的jkd
yum search java-1.7
或
yum -y list java*
#
yum -y install java-1.7.0-openjdk-devel.x86_64
# 安装完后的jdk目录
/usr/lib/jvm/
# 卸载
yum -y remove java-1.7.0-openjdk*
yum -y remove tzdata-java.noarch