Ubuntu安装配置jdk

使用paa源安装

1. 安装paa

sudo add-apt-repository ppa:webupd8team/javasudo apt-get update

2. 安装oracle-java-installer
jdk7

sudo apt-get install oracle-java7-installer

jdk8

sudo apt-get install oracle-java8-installer

安装器会提示你同意 oracle 的服务条款,选择 ok
然后选择yes 即可

如果你懒,不想自己手动点击.也可以加入下面的这条命令,默认同意条款:
JDK7 默认选择条款

echo oracle-java7-installer shared/accepted-oracle-license-v1-1 select true | sudo /usr/bin/debconf-set-selections

JDK8默认选择条款

echo oracle-java8-installer shared/accepted-oracle-license-v1-1 select true | sudo /usr/bin/debconf-set-selections

3. 设置系统默认jdk
JDK7

sudo update-java-alternatives -s java-7-oracle

JDK8

sudo update-java-alternatives -s java-8-oracle

如果即安装了jdk7,又安装了jdk8,要实现两者的切换,可以:
jdk8切换到jdk7:

sudo update-java-alternatives -s java-7-oracle

jdk7切换到jdk8

sudo update-java-alternatives -s java-8-oracle

4. 测试jdk 是是否安装成功:

java -versionjavac -version

直接下载jdk压缩包方式安装

1.官网下载JDK

地址: http://www.oracle.com/technetwork/articles/javase/index-jsp-138363.html

2. 解压缩,放到指定目录

sudo tar -zxvf jdk-8u144-linux-x64.tar.gz

3. 修改环境变量:

sudo gedit ~/.bashrc

export JAVA_HOME= #自己的JDK解压包的目录  export JRE_HOME=${JAVA_HOME}/jre  export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  export PATH=${JAVA_HOME}/bin:$PATH  

使环境变量马上生效：

source ~/.bashrc

4. 设置系统默认jdk 版本

sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.7.0_60/bin/java 300  sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.7.0_60/bin/javac 300  sudo update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.7.0_60/bin/jar 300   sudo update-alternatives --install /usr/bin/javah javah /usr/lib/jvm/jdk1.7.0_60/bin/javah 300   sudo update-alternatives --install /usr/bin/javap javap /usr/lib/jvm/jdk1.7.0_60/bin/javap 300   

然后执行:

sudo update-alternatives --config java

最后测试是否安装成功

java -version