JDK-8272079 : System.out cannot be resolved to a type in JSPs
  • Type: Bug
  • Component: core-libs
  • Affected Version: 17
  • Priority: P4
  • Status: Closed
  • Resolution: Not an Issue
  • OS: generic
  • CPU: generic
  • Submitted: 2021-08-04
  • Updated: 2021-08-09
  • Resolved: 2021-08-06
Description
ADDITIONAL SYSTEM INFORMATION :
Multiple.  We have seen this on at least Windows 10 and Linux.  

I also looked through the bug reports and could not find anything about this.

I have looked over the release notes for Java 17 (https://jdk.java.net/17/release-notes) and could not find any reference to changes to System.out that would explain this.  But this might be more of a classloading issue.

A DESCRIPTION OF THE PROBLEM :
Not sure which subcomponent this belongs under, so it might need to be adjust as needed.

When trying to use System.out.* methods in a JSP in Java 17 (currently testing with latest java 17 build 33), we get the following error when run in Open Liberty:
System.out cannot be resolved to a type

and a stack trace of (tried to clean up most of the intermingled HTML tags and noise):
JSP Processing Error
HTTP Error Code:500
Error Message: 
JSPG0049E: /updateable.jsp failed to compile
JSPG0091E: An error occurred at line: 7 in the file: /updateable.jsp
JSPG0093E: Generated servlet error from file: /updateable.jsp
/home/jazz_build/Build/jbe/build/dev/image/output/wlp/usr/servers/classloader_updateable/workarea/org.eclipse.osgi/70/data/temp/default_node/SMF_WebContainer/updateableApp/updateableAppWeb/_updateable.java : 100 : System.out cannot be resolved to a type
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.translateJsp(AbstractJSPExtensionServletWrapper.java:603)
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper._checkForTranslation(AbstractJSPExtensionServletWrapper.java:463)
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionServletWrapper.checkForTranslation(AbstractJSPExtensionServletWrapper.java:253)
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionProcessor.findWrapper(AbstractJSPExtensionProcessor.java:512)
at com.ibm.ws.jsp.webcontainerext.AbstractJSPExtensionProcessor.getServletWrapper(AbstractJSPExtensionProcessor.java:355)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:5019)
at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost$2.handleRequest(DynamicVirtualHost.java:314)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1007)
at com.ibm.ws.webcontainer.osgi.DynamicVirtualHost$2.run(DynamicVirtualHost.java:279)
at com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink$TaskWrapper.run(HttpDispatcherLink.java:1159)
at com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink.wrapHandlerAndExecute(HttpDispatcherLink.java:428)
at com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink.ready(HttpDispatcherLink.java:387)
at com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:566)
at com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.handleNewRequest(HttpInboundLink.java:500)
at com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.processRequest(HttpInboundLink.java:360)
at com.ibm.ws.http.channel.internal.inbound.HttpInboundLink.ready(HttpInboundLink.java:327)
at com.ibm.ws.tcpchannel.internal.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:167)
at com.ibm.ws.tcpchannel.internal.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:75)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.requestComplete(WorkQueueManager.java:504)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.attemptIO(WorkQueueManager.java:574)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager.workerRun(WorkQueueManager.java:958)
at com.ibm.ws.tcpchannel.internal.WorkQueueManager$Worker.run(WorkQueueManager.java:1047)
at com.ibm.ws.threading.internal.ExecutorServiceImpl$RunnableWrapper.run(ExecutorServiceImpl.java:238)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Try to serve up a very basic JSP that references a System.out method like System.out.println()

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expect it to work and not cause the "System.out cannot be resolved to a type" exception.
ACTUAL -
"System.out cannot be resolved to a type" exception thrown when used in a JSP.

---------- BEGIN SOURCE ----------
Here is a sample JSP we use in our testing that fails consistently at Java 17, but works fine a previous Java levels:

<html>
<title>updateable.jsp</title>
<body>
	<%
		String greeting = request.getParameter("greeting");
		String userName = "Joe";
		System.out.println("executing updateable.jsp - printing " + greeting + " " + userName);
	%>
	<div><%=greeting%> <%=userName%></div>
</body>
</html>
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
One of our colleges found out that by adding

<%@page import="java.io.PrintStream"%>

to the JSP prevents the "System.out cannot be resolved to a type" exception.

FREQUENCY : always
Comments
Additional Information from submitter: =========================== Just tried a similar JSP in Apache Tomcat (9.0.50) with Java 17 and that worked fine, no error. We are further investigating our code.
09-08-2021
Additional Information from submitter: =========================== We are further investigating our code. Thank you for the suggestion to try qualifying System.out.println() with java.lang within our JSPs. Unfortunately, that did not work for us. When we ran our test again, we got the same error message, just this time with a java.lang prefix : ... java.lang.System cannot be resolved ...
09-08-2021
Use java.lang.System.out.println(); should resolve the issue. Close as not an issue.
06-08-2021