I am using java-8 for multiple spring-boot projects but now one of them needs to be shifted to java-11. So I need to install both versions on my laptop. So how to handle different JAVA versions for different projects on the same machine?
Use SDKMAN https://sdkman.io/. That can help you to solve this issue.
You can give commands like:
sdk use java 8.282.08.1-amzn
or
sdk use java 11.0.10.hs-adpt
Each instance of JDK/JRE is installed into its own directory.
E.g. I have multiple JDK version in my /opt/java directory.
ls -1 /opt/java/
jdk-11.0.1
jdk1.8.0_171
openjdk-11.0.2
openjdk-14.0.1
I can switch between the versions by specifying full path to the java executable file.
E.g. running on java 11:
/opt/java/jdk-11.0.3/bin/java -jar my-springboot-app.jar
running on java 14:
/opt/java/openjdk-14.0.1/bin/java -jar my-springboot-app.jar
If you are using Unix-like system, you can also look at alternatives util. It helps to switch between different versions of applications (different java versions).
Each IDE is a separate let's say "ecosystem", and within that IDE you can set your ( in eclipse example ) java compiler and java build path java version.
Yes, you will need to install both of them on your machine, but there will be no collision between them if you set your working environment correctly within your IDEs.
The same would go for an example docker images.
If you fancy a terminal you can create a command that will switch for example MAVEN_HOME or JAVA_HOME to a specific JDK version
How to set JAVA_HOME in Linux for all users
Switching between different JDK versions in Windows
Each terminal has separate session so when you run your application on JDK8, open a new terminal, switch version, your other application will run without any issues on JDK11.
I'm trying to install the Java JDK on Windows 10 and under the Unix-style Cygwin system. I don't have admin rights though. This limits install of both Cygwin and Java JDK.
(Existing solutions here only cover JDK without admin rights).
Update:
I've found a way to do this, described in this helpful article: Installing the Java JDK on Windows 10 without admin rights. Basically, you can install Cygwin without admin rights using "--no-admin", and then extract the JDK install executable to install manually, the JDK paths can then be setup. And Java compiler (javac) ran.
you can download zip file of jdk from below link:
https://java.com/en/download/manual.jsp#win
After that set JAVA_HOME and PATH. It will work!!
I have developed a program using Java SE on Windows 7.
I build this app and it runs well on Windows.
I tried to run on Linux, so it runs but after some steps of:
Removing OpenJDK app.
Install Java JDK from terminal
Run jar file from terminal.
I need to make an installer on Windows - Linux - Mac, which installs JDK package and make the program run by double clicking.
Try using JarSplice. It is a nifty tool for converting Jar files into runnables for different systems. There are lots of tutorials on the internet on how to use it, although it is very well labelled and I found it simple enough to use.
I have a working Java SWING-based desktop application, and I'm being asked if it can be run on the Microsoft Surface Pro or Pro 2. As I understand it, these are using stock Windows 8/8.1 and will be able to run any Windows app normally, is this correct?
Are there any caveats or special considerations when running my app on these devices?
Edit: If it matters, the JRE would be distributed together with the application, so installing Java isnt an issue.
... will be able to run any Windows app normally, is this correct?
You will be able to run Java programs, but only in Desktop mode after installing the JRE. Java 7 Update 10 added official support. See Java on Windows 8 FAQ.
By default, Java is not installed on the Surface Pro. There is no java.exe or javac.exe when attempting to run from the command line. You have to go to Oracle and fetch it.
I was able to install the JRE on my Surface Pro. The package was installed in C:\Program Files (x86)\Java\jre7\bin. After the install, java.exe -version worked from the command line (after fixing PATH). The install also included an IE plugin, and it appears to have worked with IE 10 from the tablet. I was also able to install the x64 JRE. I did not try to install the JDK.
There may be something offered on the Windows App Store, too. But I don't use the store, so I don't know.
We have a couple of applications running on Java 5 and would like now to bring in an application based on Java 6. Can both java versions live together under Windows?
Is there any control panel to set the appropriate Java version for different applications, or any other way to set up, what version of Java will be used to run that particular application?
Of course you can use multiple versions of Java under Windows. And different applications can use different Java versions. How is your application started? Usually you will have a batch file where there is something like
java ...
This will search the Java executable using the PATH variable. So if Java 5 is first on the PATH, you will have problems running a Java 6 application. You should then modify the batch file to use a certain Java version e.g. by defining a environment variable JAVA6HOME with the value C:\java\java6 (if Java 6 is installed in this directory) and change the batch file calling
%JAVA6HOME%\bin\java ...
I was appalled at the clumsiness of the CLASSPATH, JAVA_HOME, and PATH ideas, in Windows, to keep track of Java files. I got here, because of multiple JREs, and how to content with it. Without regurgitating information, from a guy much more clever than me, I would rather point to to his article on this issue, which for me, resolves it perfectly.
Article by: Ted Neward: Multiple Java Homes: Giving Java Apps Their Own JRE
With the exponential growth of Java as a server-side development language has come an equivablent
exponential growth in Java development tools, environments, frameworks, and extensions.
Unfortunately, not all of these tools play nicely together under the same Java VM installation. Some
require a Servlet 2.1-compliant environment, some require 2.2. Some only run under JDK 1.2 or above,
some under JDK 1.1 (and no higher). Some require the "com.sun.swing" packages from pre-Swing 1.0
days, others require the "javax.swing" package names.
Worse yet, this problem can be found even within the corporate enterprise, as systems developed using
Java from just six months ago may suddenly "not work" due to the installation of some Java Extension
required by a new (seemingly unrelated) application release. This can complicate deployment of Java
applications across the corporation, and lead customers to wonder precisely why, five years after the
start of the infamous "Installing-this-app-breaks-my-system" woes began with Microsoft's DLL schemes,
we still haven't progressed much beyond that. (In fact, the new .NET initiative actually seeks to solve the
infamous "DLL-Hell" problem just described.)
This paper describes how to configure a Java installation such that a given application receives its own,
private, JRE, allowing multiple Java environments to coexist without driving customers (or system
administrators) insane...
It is absolutely possible to install side-by-side several JRE/JDK versions. Moreover, you don't have to do anything special for that to happen, as Sun is creating a different folder for each (under Program Files).
There is no control panel to check which JRE works for each application. Basically, the JRE that will work would be the first in your PATH environment variable. You can change that, or the JAVA_HOME variable, or create specific cmd/bat files to launch the applications you desire, each with a different JRE in path.
We can install multiple versions of Java Development kits on the same machine using SDKMan.
Some points about SDKMan are as following:
SDKMan is free to use and it is developed by the open source community.
SDKMan is written in bash and it only requires curl and zip/unzip programs to be present on your system.
SDKMan can install around 29 Software Development Kits for the JVM such as Java, Groovy, Scala, Kotlin and Ceylon. Ant, Gradle, Grails, Maven, SBT, Spark, Spring Boot, Vert.x.
We do not need to worry about setting the _HOME and PATH environment variables because SDKMan handles it automatically.
SDKMan can run on any UNIX based platforms such as Mac OSX, Linux, Cygwin, Solaris and FreeBSD and we can install it using following commands:
$ curl -s "https://get.sdkman.io" | bash
$ source "$HOME/.sdkman/bin/sdkman-init.sh"
Because SDKMan is written in bash and only requires curl and zip/unzip to be present on your system. You can install SDKMan on windows as well either by first installing Cygwin or Git Bash for Windows environment and then running above commands.
Command sdk list java will give us a list of java versions which we can install using SDKMan.
Installing Java 8
$ sdk install java 8.0.201-oracle
Installing Java 9
$ sdk install java 9.0.4-open
Installing Java 11
$ sdk install java 11.0.2-open
Uninstalling a Java version
In case you want to uninstall any JDK version e.g., 11.0.2-open you can do that as follows:
$ sdk uninstall java 11.0.2-open
Switching current Java version
If you want to activate one version of JDK for all terminals and applications, you can use the command
sdk default java <your-java_version>
Above commands will also update the PATH and JAVA_HOME variables automatically. You can read more on my article How to Install Multiple Versions of Java on the Same Machine.
It should be possible changing setting the JAVA_HOME environment variable differently for specific applications.
When starting from the command line or from a batch script you can use set JAVA_HOME=C:\...\j2dskXXX to change the JAVA_HOME environment.
It is possible that you also need to change the PATH environment variable to use the correct java binary. To do this you can use set PATH=%JAVA_HOME%\bin;%PATH%.
I use a simple script when starting JMeter with my own java version
setlocal
set JAVA_HOME="c:\java8"
set PATH=%JAVA_HOME%\bin;%PATH%;
java -version
To have a java "portable"
you can use this method here:
https://www.whitebyte.info/programming/java/how-to-install-a-portable-jdk-in-windows-without-admin-rights
Or use links. While it is rather unpleasant to update the PATH in a running environment, it's easy to recreate a link to a new version of JRE/JDK. So:
install different versions of JDK you want to use
create a link to that folder either by junction or by built-in mklink command
set the PATH to the link
If other version of java is to be used, delete the link, create a new one, PATH/JAVA_HOME/hardcoded scripts remain untouched
Invoking Java with "java -version:1.5", etc. should run with the correct version of Java. (Obviously replace 1.5 with the version you want.)
If Java is properly installed on Windows there are paths to the vm for each version stored in the registry which it uses so you don't need to mess about with environment versions on Windows.
If you use Java Web Start (you can start applications from any URL, even the local file system) it will take care of finding the right version for your application.
Using Java Web Start, you can install multiple JRE, then call what you need.
On win, you can make a .bat file:
1- online version:
<your_JRE_version\bin\javaws.exe> -localfile -J-Djnlp.application.href=<the url of .jnlp file.jnlp> -localfile -J "<path_temp_jnlp_file_.jnlp>"
2- launch from cache:
<your_JRE_version\bin\javaws.exe> -localfile -J "<path_of_your_local_jnlp_file.jnlp>"