This issue is related to running a Java program (jar) dependent on thirdparty jar library even after setting classpath and trying so many other methods by reading articles in Internet. I want to use a thirdparty Pack1.jar (it is not a part of jvm) as dependency of my programme. I do not know where the Pack1.jar file could be in the deployment machine and I want the deployer to specify the path for the thirdparty libraries I have tried the following alternatives in vain Setting the java.class.path programatically String class_path = args[0]; System.setProperty("java.class.path",class_path); Here I am assuming that deployer would supply the classpath as first argument while running the program Setting the CLASSPATH env_var to locate the thirdparty directory While running, using the classpath option java -classpath /path/to/Pack1.jar -jar Pack2.jar I think this would not work because documentation says that classpath is ignored when program is run with "java -jar" Setting the java.ext.dirs programatically. Setting the java.library.path programatically. I do not want to specify the Class-Path in manifest because that takes only relative path and I do not know where the thirdparty library would be kept in deployment machine But I am unable to get the jar running. How can I fix this problem any help please.