Javax classpath question

kofibull · 09-06-2006, 07:49 PM

I am trying to complile this program

import java.io.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

public class HelloTag extends TagSupport{
private String name = "World";

public void setName(String name){
this.name = name;
}

public int doEndTag(){
try{
pageContent.getOut().println("Hello " + name);
}
catch(IOException e){}//Ignore it
return EVAL_PAGE;
}
}

and I hav 5 errors to include below;
I can complile other java programs but this will not work.
HelloTag.java:3: package javax.servlet.jsp does not exist
import javax.servlet.jsp.*;
^
HelloTag.java:4: package javax.servlet.jsp.tagext does not exist
import javax.servlet.jsp.tagext.*;

What is the problem?

gilead · 09-06-2006, 07:55 PM

It looks like the jar files containing your classes for import aren't on your classpath. Once you add them to your classpath that particular error should go away.

Also, please don't mark posts as urgent.

kofibull · 09-06-2006, 10:07 PM

How do I get to my classpath? and what files do I need to add?

gilead · 09-06-2006, 10:55 PM

I can only guess what files you'll need to add, but it looks like jsp-api.jar from the tomcat distribution. You can run javac with something like this - I'm not at my box at the moment, so this may need tweaking:

Code:

javac -classpath .:/path/to/jsp-api.jar yourfile.java

That runs the java compiler with a classpath made up of the current directory and the path (which you'll need to change for your system) to the jsp-api.jar. Have a look for jsp-api.jar in your tomcat installation directory under common/lib.

Dan04 · 09-06-2006, 11:09 PM

Quote:

Originally Posted by kofibull

How do I get to my classpath?

Type echo $CLASSPATH at the shell to see what it is.

kofibull · 09-07-2006, 10:31 AM

First thanks all for your help,
I typed echo $CLASSPATH and it did not do anything but print blank, and I tried the javac -classpath .: path/to/jar-api.jar .java but that still did not work.

I am able to compile my other java file but can if it contains javax.

gilead · 09-07-2006, 02:46 PM

Try the following code (please note I use pageContext not pageContent):

Code:

import java.io.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

public class HelloTag extends TagSupport {
  private String name = "World";

  public void setName(String name){
    this.name = name;
  }

  public int doEndTag(){
  try{
    pageContext.getOut().println("Hello " + name);
  }
  catch(IOException e)
  {}//Ignore it
  return EVAL_PAGE;
  }
}

The command line I used to compile it follows. Note that you will have to change the path to jsp-api.jar to whatever it is on your system:

Code:

javac -cp .:/usr/local/apache-tomcat/common/lib/jsp-api.jar HelloTag.java

kofibull · 09-07-2006, 03:20 PM

Hot digi-di, Steve u did it!!!
Thanks it works. I would like to clean it up were I could just type javac HelloTag.java. Could this be possible???

And also, do u know anything about custom tags, how to set it up.

<% taglib prefix="ora" uri="orataglib"" %>
I dont understand the uri, how it reference to the TLD file.

gilead · 09-07-2006, 10:55 PM

Sure - if you're using bash as your shell, add the following to .bash_profile in your home directory:

Code:

export CLASSPATH="${CLASSPATH}:.:/usr/local/apache-tomcat/common/lib/jsp-api.jar"

The uri value orataglib needs to match the one used in <taglib-uri> in the web.xml file. There's some info at http://jakarta.apache.org/taglibs/tutorial.html which may help. Also, have a look at http://java.sun.com/developer/techni...rss_utilities/ and http://www.orionserver.com/docs/tuto...taglibs/1.html - they may also be useful.

kofibull · 09-08-2006, 11:03 AM

Thanks alot folks. Its done, classpath set and javac works so far.
But I have another problem, running graphics on my linux box.
From a remote PC if I try to run a graphics program I get this error
Exception in thread "main" java.lang.InternalError:
Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:134)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
at java.awt.Window.init(Window.java:231)
at java.awt.Window.<init>(Window.java:275)
at java.awt.Frame.<init>(Frame.java:401)
at javax.swing.JFrame.<init>(JFrame.java:198)
at FrameDemo.<init>(FrameDemo.java:6)
at ShowFrames.main(ShowFrames.java:5)

Any help with this issue??

Thanks.