Linux下JDK 1.7的安装与旧版本Java的卸载指南

首先先检查linux机器上是否有自带的jdk
java -version检查下就可以，如果有版本低的话可以先卸载掉方法如下
[root@localhost java]# rpm -qa|grep gcj 或者 rpm -qa|grep java
libgcj-4.1.2-44.el5
java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
如果没有信息就是没有安装、如果有那么如下操作
[root@localhost jdk-6u13-linux-i586]# yum -y remove java-1.4.2-gcj-compat-1.4.2.0-40jpp.115   或者 rpm -e --nodeps java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Loaded plugins: rhnplugin, security
This system is not registered with RHN.
RHN support will be disabled.
Setting up Remove Process
Resolving Dependencies
--> Running transaction check
---> Package java-1.4.2-gcj-compat.i386 0:1.4.2.0-40jpp.115 set to be erased
--> Processing Dependency: java-gcj-compat for package: antlr
--> Processing Dependency: java-gcj-compat for package: antlr
--> Processing Dependency: java-gcj-compat >= 1.0.64 for package: gjdoc
--> Processing Dependency: java-gcj-compat >= 1.0.64 for package: gjdoc
--> Running transaction check
---> Package antlr.i386 0:2.7.6-4jpp.2 set to be erased
---> Package gjdoc.i386 0:0.7.7-12.el5 set to be erased
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package                   Arch     Version                 Repository     Size
================================================================================
Removing:
 java-1.4.2-gcj-compat     i386     1.4.2.0-40jpp.115       installed      441