Method to Update Java Class Library in Client Computer at Runtime
Original Publication Date: 2001-May-26
Included in the Prior Art Database: 2003-Jun-18
Disclosed is a method to update Java class library in a client computer at runtime. It aims at improving the efficiency of the version control of Java classes distributed in client computers. Java classes are usually downloaded to the client computer from the server computer when Java program is executed as an Applet in a browser. In such case, the version of Java classes can be maintained automatically by putting the proper version of Java classes in the server computer. However, if the network performance between the server and client is not enough to download the Java classes, the class files (or any form of library data such as Jar file) should be installed to the client computer locally and loaded from there to run an Applet. Once the Java classes are installed in the client computer, the version of Java classes cannot be maintained automatically. This disclosure addresses the method to update the Java classes in the client computer automatically at runtime when the version of Java class in the server computer is updated. Target Java classes are put in both server and client computers with corresponding version information. When an Applet is loaded into a browser, the Applet loads associated Java classes by a specialized class loader. The specialized class loader is an extension of the standard class loader, and checks the version of the requested class in the client and the server before loading the class. If the versions are same, the class loader loads the requested class from the client computer, but if the versions are not same, the class loader loads the updated class from the server. In addition to load the updated class from the server, the specialized class loader may store the class file into the client computer and updates the corresponding version information in the client computer.