How Linux looks at the JDK installation path

How do I find the JDK installation path on a Linux server? Are there ways to find the installation path for locating the JDK? Are there some limitations? Here's a summary of how to find the JDK installation path.

1:echo $JAVA _home

If you use $java_home, you can locate the installation path of the JDK as long as the environment variable $java_home is configured, otherwise the installation path of the JDK is not located at all.

[Email protected] ~]# 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)

[Email protected] ~]# echo $JAVA _home

2:which Java

First of all, make a statement that which Java is not located in the installation path. Which Java navigates to the execution path of the Java program. The information on the Internet is the same, not to think at all. So how do you navigate to the Java installation path? Let's take a look at the example below, as shown below:

[Email protected] ~]# 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)

[email protected] ~]# which Java

/usr/bin/java

Ls-lrt/usr/bin/java

lrwxrwxrwx. 1 root root 15:12/usr/bin/java-/etc/alternatives/java

[Email protected] ~]# Ls-lrt/etc/alternatives/java

lrwxrwxrwx. 1 root root 15:12/etc/alternatives/java/usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java

[Email protected] ~]# CD/USR/LIB/JVM

[[email protected] 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

The same is true of Whereis Java, which itself cannot navigate to the installation path. You can use the example above to locate the installation path

3:RPM-QL PackageName

If the JDK is installed in the source code, then this method is not feasible. That is to say RPM–QL PackageName also has certain limitation.

[Email protected] ~]# 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)

[Email protected] ~]# 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

[Email protected] ~]# 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

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How Linux looks at the JDK installation path