Basic Customization > Windchill Customization Basics > Managing Customizations > Best Practices for Customizing Files Supplied by PTC > Managing Client JAR Files > Managing Client JAR Contents
  
Managing Client JAR Contents
For optimal performance, all resources (.class files, .properties files, etc.) needed by a Windchill applet should be contained within one of the client JARs it uses. Each resource not found within one of an applet's client JARs that is needed by the applet will require a separate round-trip network request and the resource will not be compressed as it would be if it was part of a client JAR. This leads to especially poor performance on slow or wide-area networks. Providing the correct content in a client JAR file helps ensure optimal performance of the applet. If you have any customized applets, their JARs may not contain all the custom resources they require. If you suspect that the client JAR file used by an applet does not have the correct contents, you can determine which missing resources should be added.
After customizing applets or JARs, you can identify what resources are used by an applet but are not contained in the corresponding client JAR files as they should be. If you are using the PTC HTTP Server (powered by Apache), PTC provides the HTTP Request Log utility that can be used to identify resources that are missing from a client JAR file and can then be added to the client JAR file.
Use the following steps to determine which resources are missing from a set of client JAR files.
1. Open the HTTP Request Log utility. This marks the location of the current end of the PTC HTTP Server (powered by Apache) log file so that all entries added to the file can be examined to see if they identify resources that have been downloaded to the client.
2. In a browser window, open the applet associated with the client JAR files and test the applet functionalities you wish to ensure/troubleshoot the performance of.
Any resource downloaded for use in the client is recorded in the Web server access log. The HTTP Request Log utility searches the log file for the resource requests made of types peculiar to applets (for example, .class and .properties files) since you opened the utility in step 1. These resources were not found in the client JARs and thus were being pulled from the Web server.
3. Use the results from the utility to update the appropriate client JAR files.
The following section provides details about using the HTTP Request Log utility.