I am new to linuxI have a Kali 2.0. I was trying to install jdk 8 on it. I couldn't do it via terminal.I downloaded the jdk package from Java website and extracted it using tar -xf to my home directoryAdded the directory containing javac to my path variable permanently.And I removed the existing Java 1.7 It said something like /usr/bin/javac missing.I guess I was feeling really stupid but I copied all the files from the jdk folder I downloaded onto /usr/bin/  and tried the javac command.This time it said some lib file wasn't found so I opened each folder from the jdk folder I downloaded and copied all the files and not the folders from each folder onto the /usr/bin/ directory.I have no idea what I did but now when I try to install the old jdk I had (using apt-get install openjdk-7-jdk) it gets installed but then when I try javac , I get the same message some lib file is missing.Could someone please tell me what I did to my system and how can I fix it?
Undo changes made to files in /usr/bin/
linux;kali linux;system recovery