I'm setting up a JSP webapp on an Ubuntu 22.04 system. The webapp uses Tomcat 9 proxied through Apache 2, just as described here <https://tomcat.apache.org/tomcat-9.0-doc/proxy-howto.html> . I'm recreating a setup that works on an Ubuntu 20.04/Tomcat 9 system, and has worked in the past for earlier versions of both Ubuntu and Tomcat.
When I access the page https://localhost/app/foo, I get a 500 Internal Server Error. The error message is java.lang.UnsupportedClassVersionError: org/eclipse/jdt/internal/compiler/env/INameEnvironment has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0 The exception is javax.servlet.ServletException: java.lang.UnsupportedClassVersionError: org/eclipse/jdt/internal/compiler/env/INameEnvironment has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0 org.apache.jasper.servlet.JspServlet.service(JspServlet.java:332) javax.servlet.http.HttpServlet.service(HttpServlet.java:764) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) There is no file by any variation of the name `INameEnvironment` in my webapp code, and that string does not appear in any file. I recognize Eclipse as a popular IDE, but I don't use it. The full stack trace (which I can provide if anyone thinks it would be useful) doesn't refer to any other file I recognize. Searching through the Tomcat source code on GitHub, I found the file ` java/org/apache/jasper/compiler/JDTCompiler.java` that appears to be the source of the error. This link takes you to the code snippet in question: https://github.com/search?q=repo%3Aapache%2Ftomcat%20INameEnvironment&type=code Is this a bug? It seems strange that it affects only one system when I've set up Tomcat 9 on many systems. Is there something on the Ubuntu 22.04 system that might cause the bug to be thrown that I can fix? The Java version on the Ubuntu 22.04 system (localhost) is ``` $ java -version openjdk version "1.8.0_362" OpenJDK Runtime Environment (build 1.8.0_362-8u362-ga-0ubuntu1~22.04-b09) OpenJDK 64-Bit Server VM (build 25.362-b09, mixed mode) ``` and the Tomcat version is ``` $ java -cp catalina.jar org.apache.catalina.util.ServerInfo Server version: Apache Tomcat/9.0.58 (Ubuntu) Server built: Jan 6 1970 15:09:28 UTC Server number: 9.0.58.0 OS Name: Linux OS Version: 5.19.0-38-generic Architecture: amd64 JVM Version: 1.8.0_362-8u362-ga-0ubuntu1~22.04-b09 JVM Vendor: Private Build ``` The Java version on the Ubuntu 20.04 server for which the webapp works is effectively identical: ``` $ java -version openjdk version "1.8.0_362" OpenJDK Runtime Environment (build 1.8.0_362-8u372-ga~us1-0ubuntu1~20.04-b09) OpenJDK 64-Bit Server VM (build 25.362-b09, mixed mode) ``` and its Tomcat version is ``` $ java -cp catalina.jar org.apache.catalina.util.ServerInfo Server version: Apache Tomcat/9.0.31 (Ubuntu) Server built: Nov 18 2022 19:07:15 UTC Server number: 9.0.31.0 OS Name: Linux OS Version: 5.4.0-150-generic Architecture: amd64 JVM Version: 1.8.0_362-8u372-ga~us1-0ubuntu1~20.04-b09 JVM Vendor: Private Build ``` Thanks for any help you can give me. Joel
