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Solution ID : SO8381

Last Modified : 05/02/2018

Sign MIDlet Suites with JadTool


A MIDLet suite consists of 2 files a JAR and JAD, you will need to sign the JAD and include a digital signature of the JAR in the JAD, to be able to install the MIDLet, below are the command lines for signing the JAD to distribute the MIDLet.

If you are distributing over the air the download link should point to the JAD file that verifies the JAR and installs it.

JadTool is packaged in a JAR file. To run it, open a command prompt, make sure you are in the directory containing the JatTool.jar file.

To sign MIDlets :

  1. Request and install the certificate into the keystore please use this solution: INFO185
  2. To add the certificate of the key pair from the given keystore to the JAD file.
    Java -jar JadTool.jar -addcert -keystore <keystorename> -alias <aliasname> -storepass <password> -inputjad <input_jadfile> -outputjad <output_jadfile>


  1.  To add the digital signature of the JAR file to the specified JAD file. The default value for -jarfile is the MIDlet-Jar-URL property in the JAD file.
    java -jar jadtool.jar -addjarsig -jarfile <jar_file> -keystore <keystorename> -alias <aliasname> -storepass <password> -keypass <password> -inputjad <input_jadfile> -outputjad <output_jadfile>


  1. After the MIDlet is signed you can view the certificate to see if the MIDlet is signed correctly:
    java -jar jadtool.jar -showcert -all -inputjad <input_jadfile>

Information above can also be found here: B.5.2 Signing MIDlet Suites