查看linux服务器上jdk的安装路径⽅法
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 -versionjava version \"1.7.0_65\"
OpenJDK Runtime Environment (rhel-2.5.1.2.el6_5-x86_ u65-b17)OpenJDK -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 -versionjava version \"1.7.0_65\"
OpenJDK Runtime Environment (rhel-2.5.1.2.el6_5-x86_ u65-b17)OpenJDK -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_/bin/java[root@localhost ~]#
[root@localhost ~]# cd /usr/lib/jvm[root@localhost jvm]# ls
java-1.6.0-openjdk-1.6.0.0.x86_ java-1.7.0-openjdk-1.7.0.65.x86_ jre jre-1.6.0 jre-1.6.0-openjdk.x86_ jre-1.7.0 jre-1.7.0-openjdk.x86_ 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 -versionjava version \"1.7.0_65\"
OpenJDK Runtime Environment (rhel-2.5.1.2.el6_5-x86_ u65-b17)OpenJDK -Bit Server VM (build 24.65-b04, mixed mode)[root@localhost ~]# rpm -qa | grep javatzdata-java-2014g-1.el6.noarch
java-1.6.0-openjdk-1.6.0.0-11.1.13.4.el6.x86_java-1.7.0-openjdk-1.7.0.65-2.5.1.2.el6_5.x86_
[root@localhost ~]# rpm -ql java-1.7.0-openjdk-1.7.0.65-2.5.1.2.el6_5.x86_ | more/etc/.java
/etc/.java/.systemPrefs
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jaas-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jaas-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jaas.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jce-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jce-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jce.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jdbc-stdext-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jdbc-stdext-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jdbc-stdext-3.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jdbc-stdext.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-1.7.0.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-cos-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-cos-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-cos.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-ldap-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-ldap-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-ldap.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-rmi-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-rmi-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi-rmi.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jndi.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jsse-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jsse-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/jsse.jar
/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/sasl-1.7.0.65.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/sasl-1.7.0.jar/usr/lib/jvm-exports/java-1.7.0-openjdk-1.7.0.65.x86_/sasl.jar/usr/lib/jvm-exports/jre-1.7.0-openjdk.x86_/usr/lib/jvm-private/java-1.7.0-openjdk.x86_/usr/lib/jvm-private/java-1.7.0-openjdk.x86_/jce
/usr/lib/jvm-private/java-1.7.0-openjdk.x86_/jce/vanilla/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_
/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/ASSEMBLY_EXCEPTION/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/LICENSE
/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/THIRD_PARTY_README/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin
/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/java/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/keytool/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/orbd/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/pack200/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/policytool/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/jre/bin/rmid
/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.65.x86_/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_802、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_libgcj-4.4.7-3.el6.x86_
2.然后卸载：
[root@centos6 lib]# rpm -e --nodeps libgcj-4.4.7-3.el6.x86_# 或者
[root@centos6 lib]# rpm -e --nodeps jdk-1.7.0_80-fcs.x86_
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。
