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Issue with copy JRE into docker and run java command

I am copying the working version of the JRE directory into docker and trying to run /JRE/bin/java.
But it throws ash: java not found error. I am doing the same in a linux VM . Just copying the JRE folder and executing java command which works fine in VM. I don't want to download JRE from anywhere.
Want this specific JRE bundled.How to resolve this.
I entered into the shell console and navigated to the JRE/bin/ directory and executed "java". even then it fails . The error is same ash: java not found error.
Dockerfile:
FROM alpine:latest
ENV HOME=/root \
DEBIAN_FRONTEND=noninteractive \
LANG=en_US.UTF-8 \
LANGUAGE=en_US.UTF-8 \
LC_ALL=C.UTF-8 \
DISPLAY=:0.0 \
DISPLAY_WIDTH=1024 \
DISPLAY_HEIGHT=768
RUN apk --update --upgrade add \
bash \
fluxbox \
x11vnc \
xterm \
xvfb
COPY MyJavaApp MyJavaApp/
WORKDIR /MyJavaApp
ENV PATH="./JRE/bin:${PATH}"

When are you copying the JRE directory to the docker? i.e Docker build time or after spinning up the Docker container?
Looks like you are correctly copying the local Java directory to the image, however the current location cannot access the java binaries, thus, make sure to set the PATH. It should be something like,
RUN export PATH=/JRE/bin:${PATH}
or pass the path to the ENV in the Dockerfile,
ENV PATH="/JRE/bin:${PATH}"

jpackage creates 2 copies of JRE

I use jpackage (with JDK 14) for creating a standalone JavaFX application.
The output of jpackage looks strange, it consists of two the same copies of JRE and all files in app folder, except App.cfg file, can be deleted without any problem.
Does jpackage can do not generate unnecessary files?
What I have:
I have a simple project created from Maven archetype org.openjfx:javafx-archetype-simple:0.0.3.
And I just added maven-shade-plugin for creating jar with dependencies and a simple launching class for it (like NewMain class here).
I do:
mvn package
mvn javafx:jlink
jpackage --package-type app-image --dest targetApp --name App --runtime-image target/image --main-jar testApp-1.0-SNAPSHOT.jar --input target
As result I have two folders with JRE (absolutely the same ones):
targetApp\App\runtime
targetApp\App\app\image
And all files (and folders) (JRE (~53 MB), Jar (~9 MB), classes...) in targetApp\App\app can be safely deleted, except App.cfg file.
After deleting these files I run targetApp\App\App.exe and it works fine.
The deleting reduces the size of App from 118 to 56 MB.
An additional question: I use Windows and jpackage generates the result for Windows (a lot of dll files and exe), do I can create a standalone application in Windows for Mac and Linux?

You get this result because you already created an uber-jar which contains everything in addition to what you specified via --input target which, according to the documentation, has the following effect.
All files in the input directory will be packaged into the
application image.
Try whether it works to just remove the option --input target or don't create the uber-jar. Instead use the maven-dependency-plugin to copy all dependencies into a single folder, say target/libs, and then explicitly specify --input target/libs.
Your second question:
You cannot cross-create applications for other targets, if that is your question.

You might want to check out the JPackageScriptFX project on GitHub. It contains a sample multi-module maven project structure and build scripts for Mac and Windows that will build all available package types and executables for both platforms. You can find it here: https://github.com/dlemmermann/JPackageScriptFX

My solution without Oracle's jpackage: AdoptOpenJDK + jpackager + macOS => .pkg, .dmg
Download AdoptOpenJDK_13. Unzip and put into /Library/Java/JavaVirtualMachines/adoptopenjdk-13.jdk
Download jpackager for (in my case osx) from https://mail.openjdk.java.net/pipermail/openjfx-dev/2018-September/022500.html. Unzip.
Copy jdk.packager.jar and jpackager to the /Library/Java/JavaVirtualMachines/adoptopenjdk-13.jdk/Contents/Home/bin (!!!)
In /yourworkspace/target should be the programA.jar file. (In my case it is a small program created with OpenJFX + openjdk13)
The /yourworkspace/jlink denotes on your JRE with bin,lib etc. you might have created via jlink. (In my case I have my custom JRE + JavaFX modules)
The /yourworkspace/icons contains .icns .
create jpackager.command file in your workspace with the content:
#! /bin/bash
ABSPATH=$(cd "$(dirname "$0")"; pwd -P)
launcher=`ls $ABSPATH/target/*.jar`
for eachfile in $launcher
do
if [ -f "$eachfile" ];then
echo Creating .pkg ...
echo "$eachfile"
basename="${eachfile##*/}"
/Library/Java/JavaVirtualMachines/adoptopenjdk-13.jdk/Contents/Home/bin/jpackager \
create-installer \
--runtime-image $ABSPATH/jlink \
--name ProgramA \
--input $ABSPATH/target \
--main-jar $basename \
--version 1.0 \
--copyright "Nikita Gromov 2020" \
--name "ProgramA-macos" \
--mac-bundle-name "ProgramA" \
--output $ABSPATH/appimage \
--icon $ABSPATH/icons/20200220101822955_easyicon_net_32.icns
fi
done
Double click on jpackager.command which is located in /yourworkspace and wait until the jpackager has created ProgramA-macos-1.0.pkg and ProgramA-macos-1.0.dmg under /yourworkspace/appimage
My solution without Oracle's jpackage: AdoptOpenJDK + jpackager + Windows => .msi
Install WiX (!!!) Important step.
Download AdoptOpenJDK_11. Will be installed under C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-hotspot
Download jpackager (in this case win) from https://mail.openjdk.java.net/pipermail/openjfx-dev/2018-September/022500.html. Unzip.
Copy jdk.packager.jar and jpackager to the C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-hotspot\bin (!!!)
In /yourworkspace/target should be the programA.jar file. (In my case it is a small program created with OpenJFX + openjdk11)
The /yourworkspace/jlink denotes on your JRE with bin,lib etc. you might have created via jlink. (In my case I have my custom JRE + JavaFX modules)
The /yourworkspace/icons contains .icns .
create jpackager.bat file in your /yourworkspace folder with the content:
set openjdk=C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-hotspot\bin
set saveto=%cd%
cd %openjdk%
jpackager create-installer --runtime-image %saveto%/jlink --input %saveto%/target --main-jar ProgramA.jar --version 1.0 --copyright "Nikita Gromov" --name "ProgramA-win" --output %saveto%/appimage --icon %saveto%/icons/icon.ico --win-menu --win-shortcut --win-dir-chooser
Note The ProgramA.jar should be in /yourworkspace/target path (!!!)
Double click on jpackager.bat which is located in /yourworkspace and wait until the jpackager has created ProgramA-win-1.0.msi under /yourworkspace/appimage
Custom JRE + JavaFX mods on Windows
Create /yourworkspace/jlink.bat file. The content of it should be:
SET openjdk=C:\Program Files\AdoptOpenJDK\jdk-11.0.6.10-hotspot\bin
SET fx=C:\Programme\AdoptOpenJDK\javafx-jmods-11.0.2
set saveto=%cd%
cd %openjdk%
jlink --module-path %fx% --add-modules=javafx.base --add-modules=javafx.controls --add-modules=javafx.fxml --add-modules=javafx.graphics --add-modules=javafx.web --add-modules=javafx.media --add-modules=javafx.swing --bind-services --output "%saveto%\jlink"
This creates the /yourworkspace/jlink folder with a custom JRE+JavaFX libraries which you will link to jpackager.

Create Java runtime image on one platform for another using Jlink

I created runtime image using jlink on my Linux machine. And I see linux folder under the include folder. Does it mean that I can use this runtime image only for Linux platform? If yes, are there any ways to create runtime images on one platform for another (e.g. on Linux for Windows and vice versa)

The include directory is for header files, such as jni.h, that are needed when compiling C/C++ code that uses JNI and other native interfaces. It's nothing to do with jlink.
The jlink tool can create a run-time image for another platform (cross targeting). You need to download two JDKs to do this. One for the platform where you run jlink, the other for the target platform. Run jlink with --module-path $TARGET/jmods where $TARGET is the directory where you've unzipped the JDK for the target platform.

Being generally unable to add anything to Alan Bateman's answers in terms of information, I'll offer a working example. This example illustrates using jlink on Mac OS and then running the binary on Ubuntu in a Docker container.
The salient points are as follows.
Given two simple modules, we compile on Mac OS:
javac -d build/modules \
--module-source-path src \
`find src -name "*.java"`
jar --create --file=lib/net.codetojoy.db#1.0.jar \
-C build/modules/net.codetojoy.db .
jar --create --file=lib/net.codetojoy.service#1.0.jar \
-C build/modules/net.codetojoy.service .
Assuming that the Linux 64 JDK is unpacked in a local directory (specified as command-line arg), we call jlink (on Mac OS in this example). JAVA_HOME is the crux of the solution:
# $1 is ./jdk9_linux_64/jdk-9.0.1
JAVA_HOME=$1
rm -rf serviceapp
jlink --module-path $JAVA_HOME/jmods:build/modules \
--add-modules net.codetojoy.service \
--output serviceapp
Then, assuming we've pulled the ubuntu image for Docker, we can execute the following in a Docker terminal (i.e. Linux):
docker run --rm -v $(pwd):/data ubuntu /data/serviceapp/bin/java net.codetojoy.service.impl.UserServiceImpl
TRACER : hello from UserServiceImpl
To re-iterate this feature of Java 9/jlink: Linux does not have Java installed and the Linux binary was built on Mac OS.

How to install Intellij IDEA on Ubuntu?

I'm new to Ubuntu and Linux in general. I want to code in Java on my computer, but I'm having problems installing IntelliJ IDEA on Ubuntu. I have downloaded and extracted the file and for some reason renamed the folder to idea. I tried moving the folder to /usr/share/applications or something but I didn't have permission. I used sudo -i in terminal to gain permission but didn't manage to get out of root folder. Can anyone help me with a step by step way to move the folder, create a shortcut in the search bar or whatever it's called and install it properly?

Note: This answer covers the installation of IntelliJ IDEA. For an extended script, that covers more JetBrains IDEs, as well as help for font rendering issues, please see this link provided by brendan.
Furthermore, a manual Desktop Entry creation is optional, as newer versions of IntelliJ offer to create it on first startup.
I have my intellij int /opt folder. So what I do is:
Download Intellij
Extract intellij to /opt-folder: sudo tar -xvf <intellij.tar> -C /opt/ (the -C option extracts the tar to the folder /opt/)
Create a Desktop Entry File called idea.desktop (see example file below) and store it anywhere you want (let's assume in your home directory)
Move the idea.desktop from your home directory to /usr/share/applications: sudo mv ~/idea.desktop /usr/share/applications/
Now (in a lot) Ubuntu versions you can start the application after the GUI is restarted. If you don't know how to do that, you can restart your PC..
idea.desktop (this is for community edition version 14.1.2, you have to change the paths in Exec= and Icon= lines if the path is different for you):
[Desktop Entry]
Encoding=UTF-8
Name=IntelliJ IDEA
Comment=IntelliJ IDEA
Exec=/opt/ideaIC-14.1.2/bin/idea.sh
Icon=/opt/ideaIC-14.1.2/bin/idea.png
Terminal=false
StartupNotify=true
Type=Application
Edit
I also found a shell script that does this for you, here. The given script in the link installs Oracle Java 7 for you and gives you the choice between Community and Ultimate Edition. It then automatically downloads the newest version for you, extracts it and creates a desktop entry.
I have modified the scripts to fulfill my needs. It does not install java 8 and it does not ask you for the version you want to install (but the version is kept in a variable to easily change that). You can also update Intellij with it. But then you have to (so far) manually remove the old folder! This is what i got:
Edit2
Here is the new version of the script. As mentioned in the comments, breandan has updated the script to be more stable (the jetbrains website changed its behavior). Thanks for the update, breandan.
#!/bin/sh
echo "Installing IntelliJ IDEA..."
# We need root to install
[ $(id -u) != "0" ] && exec sudo "$0" "$#"
# Attempt to install a JDK
# apt-get install openjdk-8-jdk
# add-apt-repository ppa:webupd8team/java && apt-get update && apt-get install oracle-java8-installer
# Prompt for edition
#while true; do
# read -p "Enter 'U' for Ultimate or 'C' for Community: " ed
# case $ed in
# [Uu]* ) ed=U; break;;
# [Cc]* ) ed=C; break;;
# esac
#done
ed=C
# Fetch the most recent version
VERSION=$(wget "https://www.jetbrains.com/intellij-repository/releases" -qO- | grep -P -o -m 1 "(?<=https://www.jetbrains.com/intellij-repository/releases/com/jetbrains/intellij/idea/BUILD/)[^/]+(?=/)")
# Prepend base URL for download
URL="https://download.jetbrains.com/idea/ideaI$ed-$VERSION.tar.gz"
echo $URL
# Truncate filename
FILE=$(basename ${URL})
# Set download directory
DEST=~/Downloads/$FILE
echo "Downloading idea-I$ed-$VERSION to $DEST..."
# Download binary
wget -cO ${DEST} ${URL} --read-timeout=5 --tries=0
echo "Download complete!"
# Set directory name
DIR="/opt/idea-I$ed-$VERSION"
echo "Installing to $DIR"
# Untar file
if mkdir ${DIR}; then
tar -xzf ${DEST} -C ${DIR} --strip-components=1
fi
# Grab executable folder
BIN="$DIR/bin"
# Add permissions to install directory
chmod -R +rwx ${DIR}
# Set desktop shortcut path
DESK=/usr/share/applications/IDEA.desktop
# Add desktop shortcut
echo -e "[Desktop Entry]\nEncoding=UTF-8\nName=IntelliJ IDEA\nComment=IntelliJ IDEA\nExec=${BIN}/idea.sh\nIcon=${BIN}/idea.png\nTerminal=false\nStartupNotify=true\nType=Application" -e > ${DESK}
# Create symlink entry
ln -s ${BIN}/idea.sh /usr/local/bin/idea
echo "Done."
Old Version
#!/bin/sh
echo "Installing IntelliJ IDEA..."
# We need root to install
[ $(id -u) != "0" ] && exec sudo "$0" "$#"
# define version (ultimate. change to 'C' for Community)
ed='U'
# Fetch the most recent community edition URL
URL=$(wget "https://www.jetbrains.com/idea/download/download_thanks.jsp?edition=I${ed}&os=linux" -qO- | grep -o -m 1 "https://download.jetbrains.com/idea/.*gz")
echo "URL: ${URL}"
echo "basename(url): $(basename ${URL})"
# Truncate filename
FILE=$(basename ${URL})
echo "File: ${FILE}"
# Download binary
wget -cO /tmp/${FILE} ${URL} --read-timeout=5 --tries=0
# Set directory name
DIR="${FILE%\.tar\.gz}"
# Untar file
if mkdir /opt/${DIR}; then
tar -xvzf /tmp/${FILE} -C /opt/${DIR} --strip-components=1
fi
# Grab executable folder
BIN="/opt/$DIR/bin"
# Add permissions to install directory
chmod 755 ${BIN}/idea.sh
# Set desktop shortcut path
DESK=/usr/share/applications/IDEA.desktop
# Add desktop shortcut
echo -e "[Desktop Entry]\nEncoding=UTF-8\nName=IntelliJ IDEA\nComment=IntelliJ IDEA\nExec=${BIN}/idea.sh\nIcon=${BIN}/idea.png\nTerminal=false\nStartupNotify=true\nType=Application" > ${DESK}
echo "Done."

You can also try my ubuntu repository: https://launchpad.net/~mmk2410/+archive/ubuntu/intellij-idea
To use it just run the following commands:
sudo apt-add-repository ppa:mmk2410/intellij-idea
sudo apt-get update
The community edition can then installed with
sudo apt-get install intellij-idea-community
and the ultimate edition with
sudo apt-get install intellij-idea-ultimate

JetBrains has a new application called the Toolbox App which quickly and easily installs any JetBrains software you want, assuming you have the license. It also manages your login once to apply across all JetBrains software, a very useful feature.
To use it, download the tar.gz file here, then extract it and run the included executable jetbrains-toolbox. Then sign in, and press install next to IntelliJ IDEA:
If you want to move the executable to /usr/bin/ feel free, however it works fine out of the box wherever you extract it to.
This will also make the appropriate desktop entries upon install.

Since Ubuntu 18.04 installing Intellij IDEA is easy! You just need to search "IDEA" in Software Center. Also you're able to choose a branch to install (I use EAP).
For earlier versions:
According to this (snap) and this (umake) articles the most comfortable ways are:
to use snap-packages (since versions IDEA 2017.3 & Ubuntu 14.04):
install snapd system. Since Ubuntu 16.04 you already have it.
install IDEA snap-package or even EAP build
to use ubuntu-make
(for Ubuntu versions earlier than 16.04 use apt-get command instead apt):
Add PPA ubuntu-desktop/ubuntu-make (if you install ubuntu-make from standard repo you'll see only a few IDE's):
$ sudo add-apt-repository ppa:ubuntu-desktop/ubuntu-make
Install ubuntu-make:
$ sudo apt update
$ sudo apt install ubuntu-make
install preffered ide (IDEA, for this question):
$ umake ide idea
or even ultimate version if you need:
$ umake ide idea-ultimate
I upgrade Intellij IDEA via reinstalling it:
$ umake -r ide idea-ultimate
$ umake ide idea-ultimate

TL;DR:
Download IntelliJ IDEA from here.
cd Downloads
extract the downloaded file: sudo tar xf ideaIC-2017.2.5.tar.gz -C /opt/
Switch to the bin directory: cd /opt/idea-IC-172.4343.14/bin
Run idea.sh from the bin subdirectory.

Since Ubuntu 16.04 includes snapd by default.
So, the easiest way to install the stable version is
IntelliJ IDEA Community:
$ sudo snap install intellij-idea-community --classic
IntelliJ IDEA Ultimate:
$ sudo snap install intellij-idea-ultimate --classic
For the latest version use channel --edge
$ sudo snap install intellij-idea-community --classic --edge
Here is the list of all channels https://snapcraft.io/intellij-idea-ultimate (drop down 'All versions').
options
--classic
The --classic option is required because the IntelliJ IDEA snap requires full access to the system, like a traditionally packaged application.
[https://www.jetbrains.com/help/idea/install-and-set-up-product.html#install-on-linux-with-snaps]
--edge
--edge Install from the edge channel
[http://manpages.ubuntu.com/manpages/bionic/man1/snap.1.html]
Note: Snap, also work a few major distributions: Arch, Debian, Fedora, openSUSE, Linux Mint,...

Recent IntelliJ versions allows automatic creation of desktop entry. See this gist
Launch from commandline. If launching for the first time, setup will ask about creating a desktop launcher icon; say yes. Or else after launching (ie. from the commandline) any time, use the IDEA menu Configure > Create Desktop Entry . That should create /usr/share/applications/intellij-idea-community.desktop
Trigger the Ubuntu desktop search (ie. Windows key), find the Intellij IDEA you used to create the desktop entry.
Drag the icon it's showing into the Ubuntu Launcher.

In a simple manner you can also try to just run a pre-packaged docker with intellij, I found the good job of #dlsniper : https://hub.docker.com/r/dlsniper/docker-intellij/
you just need to have docker installed and to run :
docker run -tdi \
--net="host" \
--privileged=true \
-e DISPLAY=${DISPLAY} \
-v /tmp/.X11-unix:/tmp/.X11-unix \
-v ${HOME}/.IdeaIC2016.1_docker:/home/developer/.IdeaIC2016.1 \
-v ${GOPATH}:/home/developer/go \
dlsniper/docker-intellij

Standalone installation
Download the tarball.tar.gz.
Extract the tarball to a directory that supports file execution.
For example, to extract it to the recommended /opt directory, run the following command:
sudo tar -xzf ideaIC-2020.3.tar.gz -C /opt
Go to /opt folder and open intellij folder
Go to /bin folder and execute the command sh idea.sh
Now the application opened and create the desktop shortcut if you need

I find and follow this youtube:
https://www.youtube.com/watch?v=PbW-doAiAvI
Basically, download the tar.gz package, extract into /opt/, and then run the "idea.sh" under bin folder (i.e. /opt/idea-IC-163.7743.44/bin/idea.sh)
Enjoy

I needed to install various JetBrains tools on a number of machines from CLI, so I wrote a tiny tool to help with that. It also uses cleaner APIs from JB making it hopefully more stable, and works for various JB tools.
Feel free to try it: https://github.com/MarcinZukowski/jetbrains-installer

try simple way to install intellij idea
Install IntelliJ on Ubuntu using Ubuntu Make
You need to install Ubuntu Make first. If you are using Ubuntu 16.04, 18.04 or a higher version, you can install Ubuntu Make using the command below:
sudo apt install ubuntu-make
Once you have Ubuntu Make installed, you can use the command below to install IntelliJ IDEA Community edition:
umake ide idea
To install the IntelliJ IDEA Ultimate edition, use the command below:
umake ide idea-ultimate
To remove IntelliJ IDEA installed via Ubuntu Make, use the command below for your respective versions:
umake -r ide idea
umake -r ide idea-ultimate
you may visit for more option.
https://itsfoss.com/install-intellij-ubuntu-linux/

Convert Java application to Mac OS X app

Is there a way to convert a Java application into a Mac OS X executable app?
I use NetBeans to develop in Java, and I'd like to "pack" the "dist" folder into an app (just for convenience)

Use the Apple Java Extensions and its Guide
The Apple Java Extensions contains a very complete development guide with information on the deployment of Java applications on Mac OS X and the production of application bundles. It also introduces other aspects of the Apple Java Extensions, like the support for integration with the standard Mac OS X UI.
Other references:
JarBundler.
Make a Mac OS X App Bundle
Creating a osx app bundle in Java registered to a protocol url

There is a library that let's you package your Java app
Packr: https://github.com/libgdx/packr
Packages your JAR, assets and a JVM for distribution on Windows (ZIP), Linux (ZIP) and Mac OS X (.app), adding a native executable file to make it appear like the app is a native app.
It can even minimize the JRE for you.

jar2app
Packr is a great tool, but at the time I found that I wanted something "easier to use", so jar2app was born. I know this is an old question but perhaps other people might find this program easier to use than other alternatives. If they don't, there's a direct reference in the FAQ to other alternatives (such as Packr).

You can use javapackager tool to build the application and wrap it in into an installer, the following commands show how to convert a jar file into a bundle file:
commands
mkdir -p package/macosx
cp Test.icns package/macosx
jdk=$(/usr/libexec/java_home)
$jdk/bin/javapackager -deploy -native dmg \
-srcfiles Test.jar -appclass package.Test -name Test \
-outdir deploy -outfile Test -v
cp deploy/bundles/Test-1.0.dmg installer.dmg
ls -l
open installer.dmg
To change the application icon and more info MacJava.

As of JDK14 there is also 📦 jpackage (JEP-392), currently promoted from incubation phase to a production-ready feature.
Example usage that worked with an swt app (assumes all the required jar files reside in the files folder; you can also provide a custom resource folder with --resource-dir):
jpackage --type dmg \
-i files \
-n Bigly \
--main-class com.biglybt.ui.Main \
--main-jar BiglyBT.jar \
--java-options -XstartOnFirstThread \
--mac-package-name BiglyBt \
--icon app.icns \
--verbose
For the full option list use:
jpackage --help
WARNING: It's probably debatable whether it's a bug or not, and maybe it will be addressed in a future release, but in the current version, if you specify the input folder as -i ., and do not provide a custom destination with --dest then jpackage will bundle everything in the current folder... including the bundle it just created, i.e. it goes recursive on itself when . is both the input folder and the output :D .

Since some of the links in the accepted answer are no longer available or suitable in 2020, 8 years from the question was asked, I would like to share my findings that I confirmed working today.
There is a tool, javapackager, shipped with java, can package java application on Windows, Linux, macOS for you.
Here is the official manual: https://docs.oracle.com/javase/8/docs/technotes/tools/unix/javapackager.html
(Also there are other helpful tools here: https://docs.oracle.com/javase/8/docs/technotes/tools/ )
For packaging a mac application, I used this command:
javapackager \
-deploy \
-native image \
-srcdir ./csv-encrypt-tool-mac \
-srcfiles csv-encrypt-tool.jar \
-srcfiles dict \
-srcfiles config \
-srcfiles log \
-outdir ./dist \
-outfile csv-encrypt-tool \
-appclass some.package.CsvEncToolApp \
-name "csv-encrypt-tool" \
-title "csv-encrypt-tool" \
-nosign \
-v \
-BjvmOptions=-Xmx4096m \
-BmainJar=csv-encrypt-tool.jar \
-Bicon=icon.icns
And this is the explanation:
-deploy \ # Assembles the application package for redistribution with sys JRE
-native image \ # Build a .app file. If you want a .dmg, use -native dmg
-srcdir ./csv-encrypt-tool-mac \ # directory where my jar and resource files in
-srcfiles csv-encrypt-tool.jar \ # my executable jar, path relative to -srcdir
-srcfiles dict \ # one of my resource directories, path relative to -srcdir
-srcfiles config \ # another one of my resource directories, path relative to -srcdir
-srcfiles log \ # again, one of my resource directories, path relative to -srcdir
-outdir ./dist \ # where I want the package to be put
-outfile csv-encrypt-tool \ # the output file name without extension, the final file (or bundle which is a directory actually) will be csv-encrypt-tool.app
-appclass some.package.CsvEncToolApp \ # the class with main method, which is the entry point of the whole app
-name "csv-encrypt-tool" \ # the name (not very sure what this is for)
-title "csv-encrypt-tool" \ # the title (not sure what it is either)
-nosign \ # not sign the app since this is just an internal tool, if you want to publish it, signing is necessary
-v \ # verbose
-BjvmOptions=-Xmx4096m \ # I need 4GB max heap size
-BmainJar=csv-encrypt-tool.jar \ # the jar file with main class
-Bicon=icon.icns # the icon
After the command is executed, there will be some files and directories created in dist, where I want the package be, and one of the directories is bundles. The application is put in there.
Since I just built an internal tool, there is no need to sign and packaged without other production ready options. You can refer to the official manual for help.
Hope this help others who do not know how to package an application on macOS in 2020, just like me.

So none of these options worked for me (maybe because I am running OS X 10.15, maybe because most of these projects are years old, who knows). Installing Catalina made the existing app I had built around the Java app no longer work.
Ultimately, this post helped: Just use Automator to run a script that runs the java command to launch the jar. I wanted to make an app to launch Colossus, a Java version of the old Avalon Hill board game Titan. I wrote a shell script that looks like:java -Xmx256m -jar /my/path/to/the/game/Colossus.jar net.sf.colossus.appmain.Start and then created an automator application whose only action was "Run Shell Script" that launches that script. Works like a charm, no installing Ant, no command line apps requiring you to download java vms, and best of all it uses an Apple tool so will work with newer versions of OS X.

You can try this app , it bundles your jar file into Mac app
Edit: it's easy to use , select the Jar file and an Icon. Here you can see the screen shoot.
https://github.com/aprsn/Mac-App-Creator