The project is developed under Tomcat7 and JDK7 environment and runs normally. When the project is released to Tomcat6, JDK7 environment, an inexplicable exception org.apache.jasper.JasperException: /WEB-INF/jsp/xxx_list.jsp(85,6) The function indexOf must be used with a prefix when a default namespace is not specified
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
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After changing the Tomcat6 in the server environment to Tomcat7, no exception occurs.
problem solved. The reason may be the problem of the jar package in the lib folder of the project. The jar package runs normally in Tomcat7, but there is a problem in Tomcat 6, and the jar package cannot be compatible. It is estimated that my jstl.jar package is not compatible with 6.
Summary: The development environment is best to be the same as the server environment where the project is released to avoid problems when publishing.