CentOS
在/usr/目录下创建java目录[root@localhost ~]# mkdir/usr/java [root@localhost ~]# cd /usr/java
下载jdk,然后解压[root@localhost java]# curl -O http://download.Oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.tar.gz[root@localhost java]# tar -zxvf jdk-7u79-linux-x64.tar.gz
设置环境变量:[root@localhost java]# vi /etc/profile
在profile中添加如下内容:#set java environment JAVA_HOME=/usr/java/jdk1.7.0_79 JRE_HOME=/usr/java/jdk1.7.0_79/jre CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME JRE_HOME CLASS_PATH PATH
让修改生效:[root@localhost java]# source /etc/profile
验证JDK有效性:[root@localhost java]# java -version java version '1.7.0_79'Java(TM) SE Runtime Environment (build 1.7.0_79-b15) Java HotSpot(TM) 64-Bit Server VM (build 24.79-b02, mixed mode)
查看yum库中都有哪些jdk版本(暂时只发现了openjdk):[root@localhost ~]# yum search java|grep jdk ldapjdk-javadoc.x86_64 : Javadoc for ldapjdk java-1.6.0-openjdk.x86_64 : OpenJDK Runtime Environment java-1.6.0-openjdk-demo.x86_64 : OpenJDK Demos java-1.6.0-openjdk-devel.x86_64 : OpenJDK Development Environment java-1.6.0-openjdk-javadoc.x86_64 : OpenJDK API Documentation java-1.6.0-openjdk-src.x86_64 : OpenJDK Source Bundle java-1.7.0-openjdk.x86_64 : OpenJDK Runtime Environment java-1.7.0-openjdk-demo.x86_64 : OpenJDK Demos java-1.7.0-openjdk-devel.x86_64 : OpenJDK Development Environment java-1.7.0-openjdk-javadoc.noarch : OpenJDK API Documentation java-1.7.0-openjdk-src.x86_64 : OpenJDK Source Bundle java-1.8.0-openjdk.x86_64 : OpenJDK Runtime Environment java-1.8.0-openjdk-demo.x86_64 : OpenJDK Demos java-1.8.0-openjdk-devel.x86_64 : OpenJDK Development Environment java-1.8.0-openjdk-headless.x86_64 : OpenJDK Runtime Environment java-1.8.0-openjdk-javadoc.noarch : OpenJDK API Documentation java-1.8.0-openjdk-src.x86_64 : OpenJDK Source Bundle ldapjdk.x86_64 : The Mozilla LDAP Java SDK
选择1.7版本进行安装:[root@localhost ~]# yum install java-1.7.0-openjdk安装完之后，默认的安装目录是在: /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64
设置环境变量:[root@localhost ~]# vi /etc/profile在profile文件中添加如下内容:#set java environmentJAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64JRE_HOME=$JAVA_HOME/jreCLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME JRE_HOME CLASS_PATH PATH
让修改生效:[root@localhost java]# source /etc/profile验证(同上一方法)
下载rpm安装文件:[root@localhost ~]$ curl -O http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.rpm
使用rpm命令安装:[root@localhost ~]# rpm -ivh jdk-7u79-linux-x64.rpm
设置环境变量:[root@localhost java]# vi /etc/profile
在打开的profile文件中添加如下内容:#set java environment JAVA_HOME=/usr/java/jdk1.7.0_79 JRE_HOME=/usr/java/jdk1.7.0_79/jre CLASS_PATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin export JAVA_HOME JRE_HOME CLASS_PATH PATH
让修改生效:[root@localhost java]# source /etc/profile验证(同上一方法)