I have created an executable JAR file for my Java application. If I double-click then it works fine. But I want to create installer for Mac OS, because I cannot give a JAR file
This works for me: https://github.com/Jorl17/jar2app
For any changes made in code, I just need to move updated jar file in the folder application.app/Content/Java
The very first hit on Google for "Mac Installer" is the Wikipedia article about the Mac Installer.
You can click through from there to read Apple's Software Delivery Guide. It tells you in exhaustive detail everything you could possibly want to know about this.
Please, for your own good, read up on How To Ask Questions The Smart Way. You'll get much better results that way.
Well, if this is what you looking for, How to Create a Mac Installer for Java Application give a try, many could help.
I'd agree that a jar should be sufficent; but maybe you want to check this (ClickInstall MacOSX 1.0.2) Installer Build Tool for OSX.
Try jarbundler from http://informagen.com/JarBundler/. You can create a nice OSX app including icon with it. Just ship that. The user can drag this app to Application. No explicit installation step necessary.
I use this for my projects.
Just a comment to clear some of this up. Mac applications normally dont have installers. At all. They dont have a registry and normally you just drag the icon (which is actually a folder with the executables in a specific folder structure) into the applications folder. Thats it. Thats why if you have an executable with a nice icon and you put it in a .dmg image file nobody is gonna know the difference.