Make Java JAR file self executable in linux

README.md

How to make a java jar file to be a single file executable?

Create JAR File

# javac hello/main.java 
# jar cfme hello_world.jar Manifest.txt hello.Main hello/main.class

Create java self executable shell script

# cat stub.sh hello_world.jar > hello_world.sh
# chmod u+x hello_world.sh
# ./hello_world.sh
Hello world
# 

main.java

// create it in the `hello` directory (hello/main.java)

package hello;

public class Main
{
    public static void main(String[] args)
    {
        System.out.println("Hello world");
    }
}

Manifest.txt

Manifest-version: 1.0
Created-By: 1.0 (https://github.com/plar)
Main-Class: hello.Main

stub.sh

#!/bin/sh

# extract script name
MYSELF=`which "$0" 2>/dev/null`
[ $? -gt 0 -a -f "$0" ] && MYSELF="./$0"

# setup java
java=java
if [ -n "$JAVA_HOME" ]; then
    java="$JAVA_HOME/bin/java"
fi

# extract jar from the script
jar_file=$(mktemp /tmp/java_app.XXXXX.jar)
START_JAR_LINENO=$(grep -a -m 1 -n -E "^###EOF###$" $MYSELF | cut -d':' -f1)
tail -n +$(($START_JAR_LINENO+1)) $MYSELF > $jar_file

# check if extracted jar exists and the jar file is not empty
if [ -s $jar_file ]; then
  # ... yeah, run it
  "$java" $java_args -jar $jar_file "$@" "- $BASH_LINENO -"
  # delete temp jar file and exit
  rm -rf $jar_file
else
  # ... oops
  echo "No jar attached!"
fi

exit 1

# EOF is a special marker
# We will append JAR after the EOF marker and extract it to a temporary file
# It is also important to keep an empty extra line after the marker
###EOF###