Debug Your App - INFO: validateJarFile(/path/to/app/WEB-INF/lib/servlet.jar) - jar not loaded

This page shows errors where a validateJarFile warning is thrown and how to fix them.

Table of Contents

Explanation

This error occurs during web application startup and is caused by a faulty JAR file.

In this case the container refuses to load the JAR file, although it will still continue loading the other JAR files in the project, and may even be able to start the application successfully, despite this warning.

Example

2/11/2007 19:28:21 org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive yourwar.war
2/11/2007 19:28:21 org.apache.catalina.loader.WebappClassLoader validateJarFile
INFO: validateJarFile(/path/to/app/WEB-INF/lib/servlet.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class

Cause

According to the Servlet Specification, certain JAR files should not be included in your web app, as they will alread be provided by Java or the Servlet Container, and may interfere with the existing classes (causing LinkageExceptions and other nasties).

See Also

• JAR files you should never include in your webapp

How to Fix

• Remove the offending JAR files from your application or WAR file

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