查看linux服务器上jdk的安装路径方法
如何在一台linux服务器上查找jdk的安装路径呢？ 有那些方法可以查找定位jdk的安装路径？是否有一些局限性呢？ 下面总结了一下如何查找jdk安装路径的方法.
1：echo $java_home
使用$java_home的话能定位jdk的安装路径的前提是配置了环境变量$java_home，否则如下所示，根本定位不到jdk的安装路径
[root@localhost ~]# java -version java version "1.7.0_65" openjdk runtime environment (rhel-2.5.1.2.el6_5-x86_64 u65-b17) openjdk 64-bit server vm (build 24.65-b04, mixed mode) [root@localhost ~]# echo $java_home
2：which java
首先要申明一下which java是定位不到安装路径的。which java定位到的是java程序的执行路径。网上的资料都是人云亦云，完全不去思考。那么怎么定位到java的安装路径呢？下面我们来看看例子吧,如下所示：
[root@localhost ~]# java -version java version "1.7.0_65" openjdk runtime environment (rhel-2.5.1.2.el6_5-x86_64 u65-b17) openjdk 64-bit server vm (build 24.65-b04, mixed mode) [root@localhost ~]# which java /usr/bin/java [root@localhost ~]# ls -lrt /usr/bin/java lrwxrwxrwx. 1 root root 22 aug 17 15:12 /usr/bin/java -> /etc/alternatives/java [root@localhost ~]# ls -lrt /etc/alternatives/java lrwxrwxrwx. 1 root root 46 aug 17 15:12 /etc/alternatives/java -> /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java [root@localhost ~]# [root@localhost ~]# cd /usr/lib/jvm [root@localhost jvm]# ls java-1.6.0-openjdk-1.6.0.0.x86_64 java-1.7.0-openjdk-1.7.0.65.x86_64 jre jre-1.6.0 jre-1.6.0-openjdk.x86_64 jre-1.7.0 jre-1.7.0-openjdk.x86_64 jre-openjdk [root@localhost jvm]#
whereis java 也是如此，它本身不能定位到安装路径。可以通过上面例子去定位安装路径
3： rpm -ql packagename
如果jdk是源码安装的话，那么这个方法也是行不通的。也就是说rpm –ql packagename也是有一定局限性的。
[root@localhost ~]# java -version java version "1.7.0_65" openjdk runtime environment (rhel-2.5.1.2.el6_5-x86_64 u65-b17) openjdk 64-bit server vm (build 24.65-b04, mixed mode) [root@localhost ~]# rpm -qa | grep java tzdata-java-2014g-1.el6.noarch java-1.6.0-openjdk-1.6.0.0-11.1.13.4.el6.x86_64 java-1.7.0-openjdk-1.7.0.65-2.5.1.2.el6_5.x86_64 [root@localhost ~]# rpm -ql java-1.7.0-openjdk-1.7.0.65-2.5.1.2.el6_5.x86_64 | more /etc/.java /etc/.java/.systemprefs /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64 /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jaas-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jaas-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jaas.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jce-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jce-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jce.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jdbc-stdext-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jdbc-stdext-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jdbc-stdext-3.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jdbc-stdext.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-cos-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-cos-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-cos.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-ldap-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-ldap-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-ldap.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-rmi-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-rmi-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi-rmi.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jndi.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jsse-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jsse-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/jsse.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/sasl-1.7.0.65.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/sasl-1.7.0.jar /usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_64/sasl.jar /usr/lib/jvm-exports/jre-1.7.0-openjdk.x86_64 /usr/lib/jvm-private/java-1.7.0-openjdk.x86_64 /usr/lib/jvm-private/java-1.7.0-openjdk.x86_64/jce /usr/lib/jvm-private/java-1.7.0-openjdk.x86_64/jce/vanilla /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64 /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/assembly_exception /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/license /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/third_party_readme /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/java /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/keytool /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/orbd /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/pack200 /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/policytool /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/rmid /usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_64/jre/bin/rmiregistry --more--
linux查看jdk版本、卸载jdk
一：没有设置jdk环境变量
1、查看linux上jdk所在目录
[root@centos6 ~]# echo $java_home
得到jdk所在目录 /usr/java/jdk1.7.0_80
2、进入jdk所在目录
[root@centos6 ~]# cd /usr/java/jdk1.7.0_80
3、运行
[root@centos6 jdk1.7.0_80]# ./bin/java -version
结果如图：
二：设置了环境变量
1、任意目录执行
[root@centos6 usr]# java -version
结果如图：
三：卸载jdk
1. 确定jdk的版本：
[root@centos6 lib]# rpm -qa|grep jdk [root@centos6 lib]# rpm -qa | grep gcj
可能的结果是：
jdk-1.7.0_80-fcs.x86_64 libgcj-4.4.7-3.el6.x86_64
2.然后卸载：
[root@centos6 lib]# rpm -e --nodeps libgcj-4.4.7-3.el6.x86_64 # 或者 [root@centos6 lib]# rpm -e --nodeps jdk-1.7.0_80-fcs.x86_64
以上为个人经验，希望能给大家一个参考，也希望大家多多支持www.887551.com。