Creating a portable JDK with PowerShell

March 2, 2015

At times, I’ve found myself wanting to have a specific JDK available without installing another version of Java. Past reasons include wanting to test multiple Java versions on the same system or needing to use a Java tool (ex. JConsole) without installing additional software.

With a small PowerShell script and 7-Zip installed*, you can easily create a stand-alone JDK from a JDK installer.

      [string] $jdkPath = $(throw "-jdkPath is required."),
      [string] $outputPath = $(throw "-outputPath is required.")
  if (Test-Path "$env:ProgramFiles\7-Zip\7z.exe")
      set-alias sz "$env:ProgramFiles\7-Zip\7z.exe"
      throw "$env:ProgramFiles\7-Zip\7z.exe needed"
  function Extract-File($file, $destination)
      sz x "$file" "-o$destination" -y
  function Unpack($directory)
      $files = Get-ChildItem $directory -recurse -filter "*.pack"
      foreach ($file in $files)
          $oldFile = $file.fullname
          $newFile = $oldFile.substring(0, $oldFile.length - 5) + ".jar"
          Write-Host "Unpacking $newFile"
          Start-Process "$directory\bin\unpack200" "$oldFile $newFile" -NoNewWindow -Wait
  function Print-Version($directory)
      Start-Process "$directory\bin\java.exe" "-version" -NoNewWindow -Wait
  $toolsZip = Join-Path -path $outputPath -childPath ''
  Extract-File -file $jdkPath -destination $outputPath
  Extract-File -file $toolsZip -destination $outputPath
  Unpack -directory $outputPath
  Remove-Item $toolsZip
  Print-Version $outputPath

This script has been tested with Java 1.7 and 1.8 JDK installers.

  • – The implementation assumes that 7-zip is available (to enable extraction of the Java binaries from the JDK installer).