Linux installation JDK

First, the software download
1. Download JDK (Below are 32-bit system and 64-bit system version)
Http://download.oracle.com/otn-pub/java/jdk/7u9-b05/jdk-7u9-linux-i586.tar.gz? Authparam=1350717577_c0836b48d7dc4cd4598cdd4f0d49e6f6 #32位
http://download.oracle.com/otn-pub/java/jdk/7u9-b05/jdk-7u9-linux-x64.rpm? authparam=1350717726_9b669eca29c07ddaaf6d8dc41e7a2684 #64位
# getconf Long_bit # See how many bits of the system

Second, install JDK7.0 version
1, first uninstall the server's own JDK package
# java-version #查看服务器是否安装过jdk
Java Version "1.6.0_17"
OpenJDK Runtime Environment (IcedTea6 1.7.4) (rhel-1.21.b17.el6-i386)
OpenJDK Client VM (build 14.0-b16, Mixed mode)
# Rpm-qa |grep gcj #查看服务器安装的jdk软件包信息
libgcj-4.4.4-13.el6.i686
java-1.5.0-gcj-1.5.0.0-29.1.el6.i686
# yum-y Remove java-1.5.0-gcj-1.5.0.0-29.1.el6.i686 #卸载软件包
2, Installation jdk7.0
Decompression Configuration Installation
# mkdir-p/USR/LIB/JVM
# tar zxvf jdk-7u9-linux-i586.tar.gz-c/USR/LIB/JVM
# Mv/usr/lib/jvm/jdk1.7.0_09/usr/lib/jvm/java7
3. Add jdk7.0 to System environment variables
# Cp/etc/profile/etc/profile.bak #备份
# Vi/etc/profile #编辑, add the following at the end
Export Java_home=/usr/lib/jvm/java7
Export JRE_HOME=${JAVA_HOME}/JRE
Export Classpath=.:${java_home}/lib:${jre_home}/lib
Export Path=${java_home}/bin: $PATH
# Source/etc/profile #使配置文件立即生效
Since there may be a default version of the JDK in the system, the following work will be done to set up our installed JDK as the default JDK version.
Update-alternatives--install/usr/bin/java Java/usr/lib/jvm/java7/bin/java 300
Update-alternatives--install/usr/bin/javac Javac/usr/lib/jvm/java7/bin/javac 300
Update-alternatives--install/usr/bin/jar Jar/usr/lib/jvm/java7/bin/jar 300
Update-alternatives--install/usr/bin/javah Javah/usr/lib/jvm/java7/bin/javah 300
Update-alternatives--INSTALL/USR/BIN/JAVAP JAVAP/USR/LIB/JVM/JAVA7/BIN/JAVAP 300
Execute the following command, set the default version, after this command executes, the system will list the various JDK versions that are currently present, prompting you to select
# update-alternatives--config Java
4. Testing
# java-version # test is successful
Java Version "1.7.0_09"
Java (TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot (TM) Client VM (build 23.5-b02, Mixed mode)

Linux installation JDK