卸载CentOS系统自带的jdk

[root@localhost  ~]# rpm -qa|grep jdk

java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64

java-1.7.0-openjdk-1.7.0.9-2.3.4.1.el6_3.x86_64

[root@localhost  ~]# rpm -qa|grep gcj

java-1.4.2-gcj-compat-1.4.2.0-40jpp.115  

libgcj-4.1.2-48.el5  

[root@localhost  ~]# yum -y remove java java-1.6.0-openjdk-1.6.0.0-1.50.1.11.5.el6_3.x86_64

[root@localhost  ~]# yum -y remove java java-1.7.0-openjdk-1.7.0.9-2.3.4.1.el6_3.x86_64

[root@localhost  ~]# yum -y remove java java-1.4.2-gcj-compat-1.4.2.0-40jpp.115  

[root@localhost ~]# yum -y remove libgcj-4.1.2-48.el5