How secure my Executable jar file

I developed a desktop application in Java. I converted my code in the form of Executable jar (.jar) format. Here my problem is, this jar files easily extracted by winrar/winzip. My Java class files are visible to others and also i do De-compilation process using JAD my source code are visible to everyone. is any way to protect my source code from De-compileation process.I developed a desktop application in Java. I co