Steps to Sign a JAR file using self signed Certificate

To Sign a JAR file using self signed Certificate follow below steps
keytool come with Java, so install Java First

Step1 : Create .jar file from .class file

C:\javaapp> jar cvf VideoANTyd.jar VideoANTyd.class

Step2 : Create a Key by using key tool

C:\javaapp>keytool -genkey -alias selfsigned -keyalg RSA -keysize 2048 -validity
 360
Enter keystore password:
keytool error: java.io.IOException: Keystore was tampered with, or password was
incorrect

If you get above error goto C:/Users/yourname/ and delete .keystore file

Now again

C:\javaapp>keytool -genkey -alias selfsigned -keyalg RSA -keysize 2048 -validity
 360
Enter keystore password:
Re-enter new password:
What is your first and last name?
  [Unknown]:  Name
What is the name of your organizational unit?
  [Unknown]:  VideoANT
What is the name of your organization?
  [Unknown]:  PMDOX
What is the name of your City or Locality?
  [Unknown]:  YourCity
What is the name of your State or Province?
  [Unknown]:  YourState
What is the two-letter country code for this unit?
  [Unknown]:  YourCountry
Is CN=Name, OU=VideoANT, O=PMDOX, L=YourCity, ST=YourState, C=YourCountry cor
rect?
  [no]:  yes

Enter key password for <selfsigned>
        (RETURN if same as keystore password):

Step3 : Create certificate from Above Key

C:\javaapp>keytool -export -alias selfsigned -file VideoANT.crt
Enter keystore password:
Certificate stored in file <VideoANT.crt>

Step4 :  Sign a JAR file

C:\javaapp>jarsigner VideoANTyd.jar selfsigned
Enter Passphrase for keystore:

C:\javaapp>

Success