How to pass data form jsp to servlet

[baxhuli pema]

Hello, I am passing data to my servlet through the jsp in this way:

<a href="DetyraServlet?action=listDetyra&firstName=<c:out value="${user.firstName}"/>">Something</a>

So I am passing the firstName parameter from my bean class (if I am correct). Now I want to pass the firstName through the session.getAttribute("username");
So I want to do something like this:

 
<%
	String user = (String) session.getAttribute("user");
%>

and then

<a href="DetyraServlet?action=listDetyra&firstName="<%=user%>">Something</a>

But I am getting errors when I try this. Can anyone please tell me what is my bad?

[Bear Bibeault]

Perhaps it would help if you let us know what the errors were?

[Karn Kumar]

Hi baxhuli pema,


Can you describe error you are getting , so that it will be easy to find out exact mis ?

If you are getting error on the JSP then put try-catch block and all your code inside it and print Stack Trace.

Also same can be done in the servlet .


- Chetan

[Bear Bibeault]

Chetan Dorle wrote:then put try-catch block and all your code inside it and print Stack Trace.

Not good advice -- modern JSPs should have no Java code inside them. (Even though it is clear that the OP is violating this precept.)

The best advice is for the errors to be posted so we can evaluate what is going on.

To the OP: Java code in a JSP is an obsolete practice. Please see this JspFaq entry

[baxhuli pema]

This is the error:

Dec 09, 2012 7:55:44 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [DetyraServlet] in context with path [/SimpleWebZ] threw exception 
[/detyra.jsp (line: 24, column: 24) quote symbol expected] with root cause
org.apache.jasper.JasperException: /detyra.jsp (line: 24, column: 24) quote symbol expected
	at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:42)
	at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:408)
	at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:89)
	at org.apache.jasper.compiler.Parser.parseAttribute(Parser.java:222)
	at org.apache.jasper.compiler.Parser.parseAttributes(Parser.java:162)
	at org.apache.jasper.compiler.Parser.parseAttributes(Parser.java:153)
	at org.apache.jasper.compiler.Parser.parseCustomTag(Parser.java:1236)
	at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1452)
	at org.apache.jasper.compiler.Parser.parse(Parser.java:138)
	at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
	at org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
	at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
	at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
	at controller.DetyraServlet.doGet(DetyraServlet.java:50)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
	at java.lang.Thread.run(Thread.java:722)

Thank you!

[Bear Bibeault]

It's telling you right where the error is: /detyra.jsp (line: 24, column: 24)

Look at what's there.

[baxhuli pema]

yes it is saying "quote symbol expected" so I understand that I can not enter in that way <%=user%>. That's why I am asking. If you know how can I do that. Thank you.

[Bear Bibeault]

Is that what's at line 24?

Also remember that anything that's not a JSP mechanism is merely template text and has no meaning.

And, again, you should be using JSTL and EL rather than obsolete Java scriptlets.

[baxhuli pema]

Ok I will try to figure out and I will let you know! Thank you.

[Stefan Evans]

Presuming that this is line 24:

<a href="DetyraServlet?action=listDetyra&firstName="<%=user%>">Something</a>  

There is an extra quote in there.
If the user was 'Bob' then what this would produce is:

<a Bob" rel="nofollow">Something</a>  

There are three quotes in that line of html.
I think you should be removing the second one.

Also I would suggest you do some sort of Url Encoding if you are going to build up a URL string in this fashion.

[Bear Bibeault]

The best way to format a URL in a JSP is with the JSTL <c:url> tag.

[Karn Kumar]

Ya try what Stefan has suggested . Like below


<a href="DetyraServlet?action=listDetyra&firstName=<%=user%>">Something</a>



- Chetan