Configuring JDK 8 on Windows

18 Apr 2017

This post details out steps to configure JDK 8 on Windows without running .exe file

Problem

The product that we are developing for some time now, is built and shipped based on Java 7. Now that Java 7 has officially reached end of life, we wanted to move on using Java 8, instead.

Apart from this, we were sold to loads of great stuff that Java 8 brings onto the table.

We wanted to move cautiously, refactoring our product one module at a time to avoid unwanted side effect. Even before we struck any architectural or design challenges we had to satisfy a basic requirement. In our shop Windows professional version is being used on Developer’s laptop. They already have Java 7 installed and configured on their machine.

We wanted to configure Java 8 so that it can co - exist with Java 7, without requiring to run official jdk-8uXYZ-windows-x64.exe that one can download from Oracle’s official site, where XYZ indicates respective update id. This was necessary as we did not want installer to alter Windows registry entries (that has already been made by earlier by JDK 7 installer).

How can we solve this issue ??

Solution

The solution looks more like a hack but served the purpose well.

Steps

• Download JDK 8 from Oracle’s official site. For us it is jdk-8u121-windows-x64.exe
• Download and install 7-Zip
• Copy the executable on a folder
• Right - click on the execution and from 7-Zip menu select and click Extract Here
• Once extraction completes, you should be able to see following files and a folder named .rsc in current directory
  • .data
  • .pdata
  • .rdata
  • .reloc
  • .rsrc (this one is a directory)
  • .text
  • CERTIFICATE
• (For x64 Windows machine) navigate to .rsrc\1033\JAVA_CAB10 folder. You should be able to locate a file with name 111 here
• Right - click on the execution and from 7-Zip menu select and click Extract Here
• Once extraction completes, you should be able to see tools.zip file
• Copy tools.zip into a target folder and extract it there. Lets assume this folder as D:/JavaJDK/
• As a final step, we need to unpack few files which are packed with pack200. We do that by executing this script in a console window inside the root of the JDK directory (i.e. “D:/JavaJDK/”):
  • for /R %f in (.\*.pack) do @"%cd%\bin\unpack200" -r -v -l "" "%f" "%~pf%~nf.jar"

and thereafter D:/JavaJDK/ can serve as JAVA_HOME for Jdk 8 … problem solved :-)