Hi,
I'm a newbee to linux, I am trying to locate jdk path in my centos7. I have not installed any java on my own though. But I see that when I type, java -version it specifies jdk 1.8.0_65, whereis java gives me lot of path, but if I try to navigate to check there, I can see only skyblue colored java files at /usr/bin/java, and if I'm not wrong its a softlink. I am not able to locate jdk 1.8.0_65 anywhere. I need this exact path to set in my bash_profile.

Thank you in advance.

From command line if you run "ls -l /usr/bin/java" it should output something like:
lrwxrwxrwx. 1 root root 22 Feb 22 14:09 /usr/bin/java -> /etc/alternatives/java

The l before the permissions confirms it is a symbolic link as does the arrow pointing to the linked file.

If you then do "ls -l /etc/alternatives/java" it shows you that file is also a symbolic link.
lrwxrwxrwx. 1 root root 72 Feb 22 14:09 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.71-2.b15.el7_2.x86_64/jre/bin/java

If you then do an ls -l on that file you'll see that is a regular file (i.e. not a link):
-rwxr-xr-x. 1 root root 7336 Jan 15 12:31 /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.71-2.b15.el7_2.x86_64/jre/bin/java

Your full path to that java is therefore:
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.71-2.b15.el7_2.x86_64/jre/bin/java

Unless you have reason to use a different java there is no reason not to use /usr/bin/java as the path you use.

The first link to /etc/alternatives shows you this is the preferred/default java based on "alteratives" setup. You can have multiple java versions installed and can use one of the others if required. If you do "ls -l /usr/lib/jvm" which is the parent directory of the above path you may see that other Java versions are installed such as a 1.7.x version.

You can also do "rpm -qa |grep -i java" to see which Java packages (RPM = RedHat Package Maager)) have been installed.

If you type "man alternatives" you can learn more about how alternatives works.

If you type "man rpm" you can learn more about that commad.

Thank you MensaWater. Very neatly explained. Was very useful.