ubuntu java1.7 升级 java 1.8

1 下载对应版本的安装包

2 解压后复制到 usr/lib/jvm/目录下

tar -xzvf jdk-8u131-linux-i586.gz

sudo mv jdk1.8.0_131 /usr/lib/jvm/jdk1.8.0_131

3 更新jdk

sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0_131/bin/java 1

sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0_131/bin/javac 1

根据提示输入相应的数字

sudo update-alternatives --config java

sudo update-alternatives --config javac

4 配置java_home变量

$echo $JAVA_HOME

/usr/lib/jvm/java-7-openjdk-i386

$ sudo echo export JAVA_HOME="/usr/lib/jvm/jdk1.8.0_131/" >> ~/.bashrc

$source ~/.bashrc

$echo $JAVA_HOME

$source /etc/profile