Receiving The type java.lang.CharSequence cannot be resolved. error message with Java 8 JDK

Question

I am running a war application on a Jetty server in Eclipse. When I try to open the main JSP page I get the error message below. Note: I am using Java 8, and the compiler that is packaged in our war that is throwing the exception is : org.apache.jasper_5.5.17.v201101211617.jar . Any help is appreciated thanks.

Exception:

HTTP ERROR 500

Problem accessing /help/updater/updatewar.jsp. Reason:

    Unable to compile class for JSP

An error occurred at line: 16 in the jsp file: /updater/updatewar.jsp
Generated servlet error:
The type java.lang.CharSequence cannot be resolved. It is indirectly referenced from required .class files

Caused by:

org.apache.jasper.JasperException: Unable to compile class for JSP

An error occurred at line: 16 in the jsp file: /updater/updatewar.jsp
Generated servlet error:
The type java.lang.CharSequence cannot be resolved. It is indirectly referenced from required .class files


    at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:84)
    at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:328)
    at org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:414)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:297)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:276)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:264)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:563)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:303)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    at org.eclipse.equinox.jsp.jasper.JspServlet.service(JspServlet.java:153)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180)
    at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:126)
    at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:68)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    at org.eclipse.equinox.servletbridge.BridgeServlet.service(BridgeServlet.java:120)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:598)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1367)
    at com.ibm.ccl.ut.war.filter.WelcomeFileFilter.doFilter(WelcomeFileFilter.java:51)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1338)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:484)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:119)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:233)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1065)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:413)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:192)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:999)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:117)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:111)
    at org.eclipse.jetty.server.Server.handle(Server.java:350)
    at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:454)
    at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:890)
    at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:944)
    at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:630)
    at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:230)
    at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:77)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:606)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:46)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:603)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:538)
    at java.lang.Thread.run(Thread.java:785)

Answer 1

Jetty 7 (and lower) probably does not support Java 8. In Java 8 some changes to classes were made, causing the JSP compilation failure.

Related question (same exception): Unable to compile class for JSP: The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files

Related problem in ManifoldCF (same exception): https://issues.apache.org/jira/browse/CONNECTORS-938

At least Jetty 9.2 supports Java 8: https://webtide.com/jetty-9-2-0-released/ http://www.eclipse.org/jetty/documentation/current/what-jetty-version.html