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WebLogic Server (WLS) Support Pattern: Investigating ClassCastExceptions (Doc ID 1331181.1)

Last updated on MARCH 20, 2024

Applies to:

Oracle WebLogic Server - Version 6.1 and later
Information in this document applies to any platform.


Problem Description

A ClassCastException is a runtime exception raised by the JVM when it detects an incompatible cast between two types. Such an error generally terminates the user request. This pattern attempts to give you some basic elements to understand and troubleshoot the most frequent causes of ClassCastException errors.

Problem Troubleshooting

Please note that not all of the following items would need to be done. Some issues can be solved by only following a few of the items.

Troubleshooting Steps

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In this Document
 Problem Description
 Problem Troubleshooting
Troubleshooting Steps
 Why does the problem occur?
 What is a classloader?
 Keys to understanding classloading
 Known WebLogic Server Issues
 Servlet dynamic reloading
 Using Prefer-web-inf-classes feature
 Using Filtered Classloader
 Need further help?

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