Unable to compile class for JSP error when I'm running my code in eclipse gwt project

Question

Hi I'm getting following error when I'm trying to access jsp page in my gwt project. Other pages which are not jsp pages are acessing fine.

It is strange that I'm able to see JSP file when GWT SDK is moved to bottom in build path order which is giving another error that GWT SDK is not installed

Can any one help me please ?

org.apache.jasper.JasperException: Unable to compile class for JSP
Generated servlet error:
2016/01/07 14:30:51:128 IST [ERROR] Compiler - Javac exception  <Compile failed; see the compiler error output for details.>Compile failed; see the compiler error output for details.
at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:933)
at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:757)
at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:379)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:472)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:451)
at org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:511)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:295)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:686)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1494)
at com.rapapp.gwt.server.common.util.CompressionFilter.doFilter(CompressionFilter.java:113)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1482)
at com.rapapp.gwt.server.common.util.CacheFilter.doFilter(CacheFilter.java:69)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1474)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:499)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:557)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:428)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.handler.RequestLogHandler.handle(RequestLogHandler.java:68)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:370)
at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:489)
at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:949)
at org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1011)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:644)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:235)
at org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:668)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:52)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Unknown Source)



Generated servlet error:
2016/01/07 14:30:51:129 IST [ERROR] Compiler - Env: Compile:  javaFileName=/C:/Users/USER/AppData/Local/Temp/jetty-127.0.0.1-8888-war-_-any-//org/apache/jsp\login_jsp.java

Solution

As you are not providing login.jsp file, So I want to share couple of suggestions to solve this issue.

1. Use latest tomcat - http://www.howopensource.com/2015/07/unable-to-compile-class-for-jsp-the-type-java-util-mapentry-cannot-be-resolved/

2. The jsp-api is provided by your Servlet container. Use at least 2.1 version. Change the dependency in your pom.xml

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jsp-api</artifactId>
    <version>2.1</version>
    <scope>provided</scope>
</dependency>

3. Use your bean where class name will be written with package name. As an example,

<%@ page import="com.Test.Person" %> 
<html> 
<head></head> 
<body> 
<jsp:useBean id="person" class="com.Test.Person" scope="request" /> 
<jsp:setProperty name="person" property="name" value="Tripti" /> 
This JSP Page is created by:<jsp:getProperty name="person" property="name" /> 

</body> 
</html>

4. The Tomcat container caches .java and .class files generated by the JSP parser they are used by the web application. Sometimes these get corrupted or cannot be found. This may occur after a patch or upgrade that contains modifications to JSPs.

Resolution

• Delete the contents of the <JIRA_INSTALL>/work folder if using standalone JIRA or <CATALINA_BASE>/work if using EAR/WAR installation.
• Verify the user running the JIRA application process has Read/Write permission to the<JIRA_INSTALL|CATALINA_BASE>/work directory.
• Restart the JIRA application container to rebuild the files.

There are also some other ways--

5. Classes not within a package are discouraged in modern Java, to the point where they don't work in a number of cases. Put your classes into packages (use a package statement at the top of the .java file)--all of them.

6. This problem is generated by the default values used by JspServlet, which compiles using 1.4 for source/target values.

You can configure this servlet by adding

<servlet>
    <servlet-name>jsp</servlet-name>
    <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
    <init-param>
        <param-name>compilerSourceVM</param-name>
        <param-value>1.5</param-value>
    </init-param>
    <init-param>
        <param-name>compilerTargetVM</param-name>
        <param-value>1.5</param-value>
    </init-param>
    <load-on-startup>3</load-on-startup>
</servlet>

7. There is one more issue as you can't configure JspServlet with the current jasper-compiler-5.0.28. You should download jasper-compiler-5.0.30 and make sure is in your classpath before gwt. There are other latest jasper compiler jars out-there but i'm not sore of how compatible are with jakarta-tomcat-5.0.28

8. https://code.google.com/archive/p/raisercostin/wikis/GwtEclipsePluginDebug.wiki

9. This maybe caused by jar conflict. Remove the servlet-api.jar in your servlet/WEB-INF/ directory, %Tomcat home%/lib already have this lib.

10. Every time I have seen those errors the reason was jasper could not find the java compiler. Try and put tools.jar in your common/lib and see if the service works then..