AWT by way of a servlet ? AWT is client side, and the codebase for a servlet container
will seldom
be configured with AWT (or Swing). Think about it . What is the "GraphicsEnvironment"
of a
process (Tomcat) which does not have a display ?
The method "getLocalGraphicsEnvironment" returns information about how to display your
windows,
text, etc. in the environment that the java process invoking it is running. Servers
(Tomcat) do
not have much of a need to do display graphics, and a such do not have the requisite
classes
installed.
These classes are usually "native", i.e. these are special native (read : machine
dependent)
library hooks for display enviornments such as microsoft windows, sun workstations
and apple
macs.
--- "Kenny G. Dubuisson, Jr." <[EMAIL PROTECTED]> wrote:
> I now was able to get my servlet to compile but I'm getting the following
> error when I try to run it in my IE browser:
>
> Apache Tomcat/4.0.5 - HTTP Status 500 - Internal Server Error
> ----------------------------------------------------------------------------
> ----
> type Exception report
> message Internal Server Error
> description The server encountered an internal error (Internal Server Error)
> that prevented it from fulfilling this request.
> exception
> javax.servlet.ServletException: Servlet execution threw an exception
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:269)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:193)
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:243)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:190)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.
> java:170)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:468)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :174)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at org.apache.ajp.tomcat4.Ajp13Processor.process(Ajp13Processor.java:458)
> at org.apache.ajp.tomcat4.Ajp13Processor.run(Ajp13Processor.java:551)
> at java.lang.Thread.run(Thread.java:479)
> root cause
> java.lang.NoClassDefFoundError
> at java.lang.Class.forName0(Native Method)
> at java.lang.Class.forName(Class.java:115)
> at
> java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment
> .java:53)
> at java.awt.Window.(Window.java:183)
> at java.awt.Frame.(Frame.java:310)
> at java.awt.Frame.(Frame.java:257)
> at javax.swing.JFrame.(JFrame.java:136)
> at HistoryFrame.(HistoryFrame.java:12)
> at g2d_2_jpg.doGet(g2d_2_jpg.java:38)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:247)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:193)
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:243)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:190)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2347)
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.
> java:170)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:468)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :174)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at org.apache.ajp.tomcat4.Ajp13Processor.process(Ajp13Processor.java:458)
> at org.apache.ajp.tomcat4.Ajp13Processor.run(Ajp13Processor.java:551)
> at java.lang.Thread.run(Thread.java:479)
> ----------------------------------------------------------------------------
> ----
>
> This is the text of my servlet:
>
> import java.io.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> import java.awt.*;
> import java.awt.image.*;
>
> import org.w3c.dom.*;
> import org.apache.xerces.parsers.DOMParser;
> import org.xml.sax.InputSource;
>
> import com.sun.image.codec.jpeg.*;
>
> public class g2d_2_jpg extends HttpServlet {
>
> private static final int WIDTH = 480;
> private static final int HEIGHT = 400;
>
> protected void doGet(HttpServletRequest request,
> HttpServletResponse response)
> throws ServletException, IOException {
>
> ServletOutputStream out = response.getOutputStream();
> ServletContext context = this.getServletConfig().getServletContext();
>
> try {
> response.setContentType("image/jpeg");
>
> // read and parse the file specified by xml parameter
> InputStream xmlStream =
> context.getResourceAsStream(request.getParameter("xml"));
> DOMParser parser = new DOMParser();
> parser.parse(new InputSource(xmlStream));
>
> Document doc = parser.getDocument();
> Element root = doc.getDocumentElement();
>
> // create a proper size Frame object
> HistoryFrame dummy = new HistoryFrame(root);
> dummy.setSize(new Dimension(WIDTH, HEIGHT));
> BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
>
=== message truncated ===
=====
Mark Zawadzki Performance Engineer/DBA/Programmer extraordinaire’ [EMAIL PROTECTED]
[EMAIL PROTECTED]
"Democracies die behind closed doors," - Judge Damon Keith
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