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Manage multiple installations of JDK on a Windows computer

Manage multiple installations of JDK on a Windows computer

JDK Version Manager (JVMS) for Windows

There are situations where the ability to switch between different versions of JDK can be very useful. For example, if you want to test a project you're developing with the latest bleeding edge version without uninstalling the stable version of JDK, this utility can help.

Installation

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  • decompression zip and copy jvms.exe to a path what you want
  • run cmd or powershell as administrator
  • cd to folder where jvms.exe in
  • run jvms.exe init
  • Setup is complete ! Switch and install jdk see Usage Section

Usage

NAME:
   jvms - JDK Version Manager (JVMS) for Windows

USAGE:
   jvms.exe [global options] command [command options] [arguments...]

VERSION:
   2.0.0

COMMANDS:
     init        Initialize config file
     list, ls    List the JDK installations.
     install, i  Install remote available jdk
     switch, s   Switch to use the specified version.
     remove, rm  Remove a specific version.
     rls         Show a list of versions available for download.
     proxy       Set a proxy to use for downloads.
     help, h     Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h     show help
   --version, -v  print the version

how to install and switch jdk. see:

  • run cmd or powershell as administrator
  • jvms rls list available jdk version for download
  • jvms install 1.8.0_31 install jdk 1.8.0_31
  • jvms ls list installed jdk
  • jvms switch 1.8.0_31 switch jdk version to 1.8.0_31

powershell_2017-07-23_01-26-40

What's the big difference?

First and foremost, this version of jvms has no dependency on other lib. It's written in Go, which is a much more structured
approach than hacking around a limited .bat file. It does not rely on having an existing jdk installation.

The control mechanism is also quite different. There are two general ways to support multiple jdk installations with hot switching capabilities.
The first is to modify the system PATH any time you switch versions, or bypass it by using a .bat file to mimic the jdk executable and redirect
accordingly. This always seemed a little hackish to me, and there are some quirks as a result of this implementation.

The second option is to use a symlink. This concept requires putting the symlink in the system PATH, then updating its target to
the jdk installation directory you want to use. This is a straightforward approach, and seems to be what people recommend.... until they
realize just how much of a pain symlinks are on Windows. This is why it hasn't happened before.

In order to create/modify a symlink, you must be running as an admin, and you must get around Windows UAC (that annoying prompt). As a result, JVMS for Windows
maintains a single symlink that is put in the system PATH during jvms init only. Switching to different versions of JDK is a matter of
switching the symlink target. As a result, this utility does not require you to run jvms use x.x.x every time you open a console window.
When you do run jvms use x.x.x, the active version of jdk is automatically updated across all open console windows. It also persists
between system reboots, so you only need to use jvms when you want to make a change.

Overall, this project brings together some ideas, a few battle-hardened pieces of other modules, and support for newer versions of JDK.

I also wrote a simple data feed containing a list of jdk versions. It's free for anyone to use.

add a local jdk version

e.g: add the 1.7 jdk

  1. copy jdk folder to jvms/store
  2. rename folder to 1.7
  3. jvms list check this
  4. jvms switch 1.7
  5. java -version check jdk verison

Create own local download server

  • create a json file. eg. index.json
  • add you jdk download link to it. The format is like this:
    [
      {
        "version":"1.9.0",
        "url":"http://192.168.1.101/files/jdk/1.9.0.zip"
      }
    ]
    
  • copy this file to a static file server like nginx, apache etc.
  • run jvms init --originalpath http://192.168.1.101/files/index.json by the way, jvms init --java_home can modify default JAVA_HOME
  • the run jvms rls or jvms install x will list or install your jdk version

create a jdk zip file

  • open jdk_home folder
  • compression all file to *.zip file
  • copy zip file to your server
  • add this zip file link to index.json

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