How to create an executable jar file with 1 GB heap

Question

I created a class that gives a text file containing system performance as output. I want to run it as an executable Jar. but when I run the Jar I want to increa

Answer 1

<launch4jConfig>
  <dontWrapJar>false</dontWrapJar>
  <headerType>gui</headerType>
  <jar>PATH_OF_YOUR_JAR</jar>
  <outfile>PATH_OF_YOUR_EXE</outfile>
  <errTitle></errTitle>
  <cmdLine>-log_file=logs\\hp</cmdLine>
  <chdir></chdir>
  <priority>normal</priority>
  <downloadUrl>http://java.com/download</downloadUrl>
  <supportUrl></supportUrl>
  <customProcName>true</customProcName>
  <stayAlive>false</stayAlive>
  <manifest></manifest>
  <icon>PATH_OF_THE_ICON</icon>
  <singleInstance>
    <mutexName>APPLICATION_NAME</mutexName>
    <windowTitle></windowTitle>
  </singleInstance>
  <jre>
    <path>jre-w32\</path>
    <minVersion></minVersion>
    <maxVersion></maxVersion>
    <jdkPreference>preferJre</jdkPreference>
    <initialHeapSize>512</initialHeapSize>  
    <maxHeapSize>1024</maxHeapSize>
  </jre>
</launch4jConfig>

It is a launch4j Config file, here you can specify the heap size as per your requirement.

Answer 2

 java -Xms1200m -Xmx1300m -jar FILENAME.jar

Define this somewhere in the jar File or in the Manifest is not possible:

Can I set Java max heap size for running from a jar file?

Answer 3

As already mentioned: it unfortunately is not possible (without creating a wrapper, whether shortcut/script/executable ...).

If you're only running on Windows, I can recommend Launch4J to create an executable wrapper that can apply these settings on execution:

Wrapping it in a executable has other benefits:

• If a suitable version of Java is not found, it will prompt the user to download it
• Windows 7 Start Menu will treat it properly (highlighting it as a new application after installation)
• Windows Firewall will treat it properly