Problems with FOP

Hello everybody,
I have some problems with FOP...
I want to create pdf outputs and I want to use FOP to convert reports into pdf`s.
The documentation says that you have to install OC4J, but I can`t find the directorys to unzip the FOP files!
I installed the OC4J standalone version...
It is wrong?
What should I install? J2EE?
Sorry, but I am new at this topic...
I hope you would help me!
Thanks,
Tim

Kevin,
quote from the FOP homepage ( http://xmlgraphics.apache.org/fop/ ):
FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, SVG, XML (area tree representation), Print, AWT, MIF and TXT. The primary output target is PDF.
FOP (Formatting Objects Processor) is basically a mechanism to transform an XML stream of data (e.g. the pure data of a page rendered using HTML DB) into an arbitrary output format, i.e. PDF.
~Dietmar.

Similar Messages

Problems with FOP/Apache - Apex PDF printing

Hello,
I have configured
Apex 3.0.1
iAS 10.1.3.x (http + modplsql)
OC4J 10.1.3.3 (stand alone)
FOP for PDF printing
RDBMS 9.2.0.8 64bits (Solaris)
following the OTN recipee and this setup does not seem to work for all cases.
For instance, using the Apex admin interface, I go to the monitoring page :
Home -> Monitor Page -> Login Attempts
And click on the Print link (left bottom corner of the page) , it works o.k, the PDF is generated correctly.
However, if I go to
Home -> utilities -> Object Reports -> Table Storage Sizes
and click on the Print link, it does not work. A pdf file is generated with the following text
<HTML><HEAD><TITLE>500 Internal Server Error</TITLE></HEAD>
<BODY><H1>500 Internal Server Error</H1>
<PRE>Servlet error: An exception occurred. The current application deployment descriptors do not allow for including it in this response. Please consult the application log for details.</PRE>
</BODY>
</HTML>
If I check in the application log I see the following error
07/08/08 11:52:21.584 fop: Servlet error
oracle.xml.xpath.XPathException: Error in expression: './/BYTES/1024/1024'.
at oracle.xml.xslt.XSLBuilder.startElement(XSLBuilder.java:468)
at oracle.xml.parser.v2.NonValidatingParser.parseElement(NonValidatingParser.java:1288)
at oracle.xml.parser.v2.NonValidatingParser.parseRootElement(NonValidatingParser.java:336)
at oracle.xml.parser.v2.NonValidatingParser.parseDocument(NonValidatingParser.java:303)
at oracle.xml.parser.v2.XMLParser.parse(XMLParser.java:320)
at oracle.xml.xslt.XSLProcessor.newXSLStylesheet(XSLProcessor.java:712)
at oracle.xml.xslt.XSLStylesheet.<init>(XSLStylesheet.java:321)
at oracle.xml.parser.v2.XSLStylesheet.<init>(XSLStylesheet.java:114)
at apex_fop._jspService(_apex__fop.java:71)
at com.orionserver[Oracle Containers for J2EE 10g (10.1.3.3.0) ].http.OrionHttpJspPage.service(OrionHttpJspPage.java:59)
at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:462)
at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:594)
at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:518)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:713)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:370)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:871)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:453)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:221)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:122)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].server.http.HttpRequestHandler.run(HttpRequestHandler.java:111)
at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:260)
at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:239)
at oracle.oc4j.network.ServerSocketAcceptHandler.access$700(ServerSocketAcceptHandler.java:34)
at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:880)
at com.evermind[Oracle Containers for J2EE 10g (10.1.3.3.0) ].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:298)
at java.lang.Thread.run(Thread.java:595)
I do not think it is related to a config/installation issue. It seems a parsing issue with the SQL stmt being executed, but it works for some SQL code and not for other.
Some users did notice this problem this morning when testing the new PDF printing.
Any ideas ?
Nilo Segura
CERN.

ups.. sorry for the ugly formatting exercise...

Apex 1.6 problem with FOP - PDF

Hi everyone,
In my first page, I have parameters that I select. When I press on Submit button, I open my page 2 which I have my region who execute my SQL.
In this region I have a Output to PDF button.
Page
<script src="#WORKSPACE_IMAGES#htmldb_pdf.js"></script>
Region
Output to PDF Document
What can I do to have success with Pdf ?
Regards. timiche.

To add to the first message.
Do I need extra branch ????
On my region :
<....."Javascript:pdf_GrabXML('f?p=&APP_ID.:&APP_PAGE_ID.:&APP_SESSION.:FLOW_FOP_OUTPUT_#REGION_ID#')">Output to PDF Document......

Fop 0.19 problems with small files?

Hello!
I have a problem with fop 0.19 serializer: when I try to generate
pdf files smaller then cca. 10kB, IE does not open Acrobat
Reader, and sometimes even freezes. With larger files, it works
OK.
My configuration:
Tomcat 3.2
XDK 9.0.2.0b
fop 0.19
Thanks in advance!
Vedran

Hi Eric/Steve,
I have downloaded the Xml development kit for Java (9.0.2.0.0C
beta) and created a new xsql RTF-serializer class according to
the XSQLSampleSerializer included in the xsqlserializer.jar file.
I also included Eric's CustFOP-serializer.
I can compile my new class with JDeveloper but when i recreate
the xsqlserializer.jar and try to use this jar-file with the
xsql servlet i get an error.
The error is "XSQL-022: cannot load serializer class
oracle.xml.xsql.serializers.XSQLxxxSerializer", with xxx my own
serializer, but also when i use the original FOP-serializer.
So i think the jar-file is not correct.
Can anyone tell me how to recreate the xsqlserializer.jar or
tell me what else i have done wrong?
(I also posted this question in the JDeveloper-forum)

Problem in IAS Server with generation of PDF with FOP and XML parsing

Dear co.forumers :
We are developing an application that generates a pdf document with FOP Apache utilities, and this PDf is stored in a folder of the server. Firts of all, a DDBB data is retrieved using java ( jdbc) middleware classes ( servlets ), and with these data, the pdf is generated using FOP. In these process, he data retrieved from the DDBB is converted in a XML file , and the with the XSL FOP utility, the pdf is generated.
In the other hand, we have another application that consults data from a java beans, using a JSP, generates a XML with the data of the beans, and with this XML, and with a XSL file generates and html , with the data and fixed text.
Both applications have been deployed as a separated WebApp in the IAS. Both use Xalan as XML parser amb Xerces is used aswell.
So, the problem is , after generating a pdf with the firts application, every html generated via JSP-XML-XSL transformation in the second application is shown completelly bad formated. All fixed text are wrongly composed, and the text that should appear in textFields and ComboBoxes is also bad formated. The XML with the data is well generated, so the problem is in the parsing of these XML and the conversion in html through XSL. We have to re-initiate the server and then everything goes well again. If no pdf is launched, no problem occurs with the other application.
How an a WEB APP pplication can affect to another, installed both in different folders of the IAS ? We tried to change Xalan version and FOP version, but no result.
Is this a Poltergeist ?? and X file , maybe ?
Has anyone had the same problem ?
Pleae, any help will be very wellcomed.

A PDF document may be generated in the JDeveloper OC4J server.
http://www.oracle.com/technology/pub/notes/technote_vohra_fop.html

Apache FOP Problem with column width

We are using Apache FOP to generate simple pdf documents out of reports.
My problem is that the table in the pdf is as standard filled in with columns of same length.
Further on the content of some table fields is to large or sometimes there is to much room.
is there any possiblity to let fop react like html?
The smallest table field size should be like the content. I don't want to adjust all my reports, cause there are really many reports with pdf printing.
anyone an idea how to solve this with FOP?
i have no BI pubisher or other reporting engines for this problem
thx so far

Oliver,
I think what you're looking for is having your column width automatically adjusted based on the content of your column values. That is not possible with the built-in, generic XSL-FO template. What you can do is manually adjusting the column width to appropriate values on the print attributes page.
Regards,
Marc

PDF Printing with FOP 0.94

Hi,
are there any examples about printing apex report with FOP 0.94?
Thanks,
Sergio

Hi!
I am trying to get this solution working on a LINUX system using TOMCAT 6.0.18 rather than OC4J which we don't have a license for. I have tried both FOP 0.94 and 0.95 and seem to get similar problems. Here is the error message:
org.apache.jasper.JasperException: An exception occurred processing JSP page /apex_fop.jsp at line 28
25: // Setup XSLT
26: System.setProperty("javax.xml.transform.TransformerFactory","org.apache.xalan.processor.TransformerFactoryImpl");
27: TransformerFactory factory = TransformerFactory.newInstance();
28: Transformer transformer = factory.newTransformer(new StreamSource(new java.io.StringReader(request.getParameter("template"))));
29:
30: // Set the value of a <param> in the stylesheet
31: transformer.setParameter("versionParam", "2.0");
Stacktrace:
     org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
root cause
java.lang.NullPointerException
     java.io.StringReader.<init>(StringReader.java:33)
     org.apache.jsp.apex_005ffop_jsp._jspService(apex_005ffop_jsp.java:92)
     org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
     org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
     org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
     org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
     javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
Any hints, tips, suggestions, etc. gratefully welcomed!
Dave Venus

Problem with special characters (&) when printing using XSL-FO ...

Hello everybody !!
I have a problem when I want to print a Report with a link to a URL where the character "&" is present :
I want to have something like : src="file:///...webfile?param1=val1*+_&_+*param2=val2"
In my XSL-FO file, I wrote : src="file:///...webfile?param1=<xsl:value-of select="IDARTICLE"/>*+_<xsl:text>&</xsl:text>_+*param2=<xsl:value-of select="MARQUE"/>"
When I try this only with FOP, it works. However, when I upload the XSL-FO file to ApEx, it says my PDF file is corrupted when I want to open it.
What do I have to put the '&' symbol when I want to print the Report ??
Could anyone help me ??
Thanks by advance,
Pierre C.

I believe this relates to something I have actually found in my own testing.
It is probably due to the Template not being URLEncoded prior to transmission to the FOP processor.
I actually determined that special URL characters, like '+' and '&', are lost on transmission because the type of submission is POST with x-www-form-urlencoded, but the fields are not actually encoded entirely. The XML Element contents are encoded prior to transmission in order to preserve data.
Work around would be to URLEncode the template as it sits in the WWV_FLOW_REPORT_LAYOUTS. I have been able to successfully get around the problem by doing that.
-Richard
The post I describe the problem: Reports Layout->storing custom report layouts that aren't FOP/RTF
The post under the enhancement request thread: Re: Enhancement Request Thread : Post 3.1

WLS 7.0 sp2 - Servlet Problems with SOAP messages

          I'm using Weblogic 7.0 SP2 and trying to create a Servlet to receive SOAP wrapped
          XML messages. I'm getting the following error. Is this a problem with WLS7.0sp2's
          support of JAXM? The System.out.println's indicate I have successfully received
          the incoming SOAP request and then successfully formatted the SOAP response, but
          upon returning saving the response it appears to blow up. Does anyone have any
          suggestions?
          I need to do the following in a servlet:
          - receive an incoming SOAP request with an embedded XML message
          - perform some processing
          - return a SOAP response with an embedded XML message
          Should I be using JAXM? Or can I do this same task easily with JAX-RPC?
          <Feb 24, 2004 4:10:42 PM AST> <Error> <HTTP> <101017> <[ServletContext(id=260434
          7,name=isd.war,context-path=)] Root cause of ServletException
          java.lang.Error: NYI
          at weblogic.webservice.core.soap.SOAPMessageImpl.saveRequired(SOAPMessag
          eImpl.java:360)
          at javax.xml.messaging.JAXMServlet.doPost(Unknown Source)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
          at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
          at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run
          (ServletStubImpl.java:1058)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubIm
          pl.java:401)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubIm
          pl.java:306)
          at weblogic.servlet.internal.WebAppServletContext$ServletInvocationActio
          n.run(WebAppServletContext.java:5445)
          at weblogic.security.service.SecurityServiceManager.runAs(SecurityServic
          eManager.java:780)
          at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppSe
          rvletContext.java:3105)
          at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestIm
          pl.java:2588)
          at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:213)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:189)
          >
          I've stripped the code down so that all it does is verifies the incoming SOAP/XML
          request and creates a hard-coded response... be gentle... I'm a novice at this
          import javax.xml.soap.*;
          import javax.servlet.*;
          import javax.servlet.http.*;
          // import javax.xml.transform.*;
          import java.util.*;
          import java.io.*;
          public class RegisterServlet extends HttpServlet
          static MessageFactory fac = null;
          static
          try
          fac = MessageFactory.newInstance();
          catch (Exception ex)
          ex.printStackTrace();
          public void init(ServletConfig servletConfig) throws ServletException
          super.init(servletConfig);
          public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException,
          IOException
          try
          System.out.println("** Note: doPost() Entering req = " + req);
          // Get all the headers from the HTTP request
          MimeHeaders headers = getHeaders(req);
          // Get the body of the HTTP request
          InputStream is = req.getInputStream();
          // Now internalize the contents of a HTTP request
          // and create a SOAPMessage
          SOAPMessage msg = fac.createMessage(headers, is);
          System.out.println("** Note: doPost() Step A");
          SOAPMessage reply = null;
          reply = onMessage(msg);
          System.out.println("** Note: doPost() Step B reply = " + reply);
          if (reply != null)
          * Need to call saveChanges because we're
          * going to use the MimeHeaders to set HTTP
          * response information. These MimeHeaders
          * are generated as part of the save.
          if (reply.saveRequired())
          System.out.println("** Note: doPost() Step C reply.saveRequired()");
          reply.saveChanges();
          resp.setStatus(HttpServletResponse.SC_OK);
          putHeaders(reply.getMimeHeaders(), resp);
          // Write out the message on the response stream
          OutputStream os = resp.getOutputStream();
          System.out.println("** Note: doPost() Step D os = " + os);
          reply.writeTo(os);
          os.flush();
          else
          resp.setStatus(HttpServletResponse.SC_NO_CONTENT);
          catch (Exception ex)
          throw new ServletException("** Error: SAAJ POST failed: " + ex.getMessage());
          static MimeHeaders getHeaders(HttpServletRequest req)
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          MimeHeaders headers = new MimeHeaders();
          while (enum.hasMoreElements())
          String headerName = (String)enum.nextElement();
          String headerValue = req.getHeader(headerName);
          StringTokenizer values =
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          while (values.hasMoreTokens())
          headers.addHeader(headerName,
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          Iterator it = headers.getAllHeaders();
          while (it.hasNext())
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          String[] values = headers.getHeader(header.getName());
          if (values.length == 1)
          res.setHeader(header.getName(),
          header.getValue());
          else
          StringBuffer concat = new StringBuffer();
          int i = 0;
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          if (i != 0)
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          res.setHeader(header.getName(), concat.toString());
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          public SOAPMessage onMessage(SOAPMessage message)
          SOAPMessage replymsg = null;
          try
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          //Extract the ComputerPart element from request message and add to reply SOAP
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          SOAPEnvelope reqse = message.getSOAPPart().getEnvelope();
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          //System.out.println("** Note: OnMessage() Step B");
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          replymsg = fac.createMessage();
          SOAPPart sp = replymsg.getSOAPPart();
          SOAPEnvelope se = sp.getEnvelope();
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          System.out.println("** Note: OnMessage () Step C Soap Reply Before Message Body
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          se.getBody().addBodyElement(se.createName("RegisterResponse")).addChildElement(se.createName("ErrorCode")).addTextNode("000");
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          replymsg.saveChanges();
          System.out.println("** Note: OnMessage() Exiting replymsg = " + (replymsg));
          catch (Exception ex)
          ex.printStackTrace();
          return replymsg;


Michael,
I got the same error on WLS8.1/Win2K professional and apache FOP (old version).
After digging into the WLS code and FOP(old version). i found the conflict happens
on
the "org.xml.sax.parser" system property. In WLS code, they hard coded like the
following when startup weblogic server:
System.setProperty("org.xml.sax.parser", "weblogic.xml.jaxp.RegistryParser");
But the FOP code try to use the "org.xml.sax.parser" system property to find the
sax parser then conlict happens.
Here is the response from BEA support :
"I consulted with our developers regarding the question of whether we can change
the hard-coded value for the java system property: org.xml.sax.parser by using
a configuration parameter and I found that unfortunately there is no specific
setting to change the value. As you had mentioned in your note the org.xml.sax.parser
system property can be changed programmatically in your application code."
I solve my problem by using newer apache FOP (it never use the system property:org.xml.sax.parser
any more) and XML Registy for WLS8.1.
Good luck.
David Liu
Point2 Technologies Inc.
"p_michael" <[email protected]> wrote:
>
Help.
When we migrated from WLS 6.1 to WLS 7.0 SP2 when encountered a problem
with XML
parsing that did not previously exist.
We get the error "weblogic.xml.jaxp.RegistryParser is not a SAX driver".
What does this mean? And, what should we do about it.
p_michael

BIPublisher + Apex report problem with summary operator

I design report layout in Microsoft Word with Oracle BI Publisher Tempate Builder.
I need to sum two numbers:
2+2
then I create following statement (addition):
<?2+2?>
In PDF preview I see correct sum:
4
Next I save this report in RTF format and import it to APEX.
When I open this report in APEX I don't see any PDF report, because Acrobat Reader show me followin message:
"Adobe Reader could not open 'report.pdf' because it is either not a supported file type or because the file has been damaged..."
In log of BI Publisher I found this error:
[101507_093321781][][ERROR] [Line 281.40] Incorrect XPath: 2 2
[101507_093322140][oracle.apps.xdo.common.xml.XSLTWrapper][EXCEPTION] XSL error:
<Line 125, Column 101>: XML-22026: (Error) Unknown expression at EOF: 2 2.
[101507_093322140][][EXCEPTION] java.lang.reflect.InvocationTargetException
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     at java.lang.reflect.Method.invoke(Method.java:324)
     at oracle.apps.xdo.common.xml.XSLT10gR1.invokeNewXSLStylesheet(Unknown Source)
     at oracle.apps.xdo.common.xml.XSLT10gR1.transform(Unknown Source)
     at oracle.apps.xdo.common.xml.XSLTWrapper.transform(Unknown Source)
     at oracle.apps.xdo.template.fo.util.FOUtility.generateFO(Unknown Source)
     at oracle.apps.xdo.template.fo.util.FOUtility.generateFO(Unknown Source)
     at oracle.apps.xdo.template.fo.util.FOUtility.generateFO(Unknown Source)
     at oracle.apps.xdo.template.FOProcessor.createFO(Unknown Source)
     at oracle.apps.xdo.template.FOProcessor.generate(Unknown Source)
     at oracle.apps.xdo.servlet.Converter.process(Converter.java:302)
     at oracle.apps.xdo.servlet.Converter.render(Converter.java:231)
     at oracle.apps.xdo.servlet.Converter.doPost(Converter.java:95)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:824)
     at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:330)
     at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:830)
     at com.evermind.server.http.AJPRequestHandler.run(AJPRequestHandler.java:224)
     at com.evermind.server.http.AJPRequestHandler.run(AJPRequestHandler.java:133)
     at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
     at java.lang.Thread.run(Thread.java:534)
Caused by: oracle.xdo.parser.v2.XPathException: Unknown expression at EOF: 2 2.
     at oracle.xdo.parser.v2.XSLProcessor.reportException(XSLProcessor.java:806)
     at oracle.xdo.parser.v2.XSLProcessor.newXSLStylesheet(XSLProcessor.java:571)
     ... 24 more
BTW, when I multiply numbers like this:
<?2*2?>
above problems doesn't exist.

well i am facing the exact same problem in FOP too. Pdf is giving that message because the file u are generating is empty. I will keep u posted if i am able to solve this particular problem.......till then u can look up my posts to see if anything helps u.

A problem with threads

I am trying to implement some kind of a server listening for requests. The listener part of the app, is a daemon thread that listens for connections and instantiates a handling daemon thread once it gets some. However, my problem is that i must be able to kill the listening thread at the user's will (say via a sto button). I have done this via the Sun's proposed way, by testing a boolean flag in the loop, which is set to false when i wish to kill the thread. The problem with this thing is the following...
Once the thread starts excecuting, it will test the flag, find it true and enter the loop. At some point it will LOCK on the server socket waiting for connection. Unless some client actually connects, it will keep on listening indefinatelly whithought ever bothering to check for the flag again (no matter how many times you set the damn thing to false).
My question is this: Is there any real, non-theoretical, applied way to stop thread in java safely?
Thank you in advance,
Lefty

This was one solution from the socket programming forum, have you tried this??
public Thread MyThread extends Thread{
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     public void run(){
          ss.setSoTimeout(90);
          while (active){
               try{
                    serverSocket = ss.accept();
               catch (SocketTimeoutException ste){
               // do nothing
     // interrupt thread
     public void deactivate(){
          active = false;
          // you gotta sleep for a time longer than the
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          try{
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          }catch (InterruptedException ie){
          interrupt();
}

Problem with Threads and a static variable

I have a problem with the code below. I am yet to make sure that I understand the problem. Correct me if I am wrong please.
Code functionality:
A timer calls SetState every second. It sets the state and sets boolean variable "changed" to true. Then notifies a main process thread to check if the state changed to send a message.
The problem as far I understand is:
Assume the timer Thread calls SetState twice before the main process Thread runs. As a result, "changed" is set to true twice. However, since the main process is blocked twice during the two calls to SetState, when it runs it would have the two SetState timer threads blocked on its synchronized body. It will pass the first one, send the message and set "changed" to false since it was true. Now, it will pass the second thread, but here is the problem, "changed" is already set to false. As a result, it won't send the message even though it is supposed to.
Would you please let me know if my understanding is correct? If so, what would you propose to resolve the problem? Should I call wait some other or should I notify in a different way?
Thanks,
B.D.
Code:
private static volatile boolean bChanged = false;
private static Thread objMainProcess;
   protected static void Init(){
        objMainProcess = new Thread() {
            public void run() {
                while( objMainProcess == Thread.currentThread() ) {
                   GetState();
        objMainProcess.setDaemon( true );
        objMainProcess.start();
    public static void initStatusTimer(){
        if(objTimer == null)
             objTimer = new javax.swing.Timer( 1000, new java.awt.event.ActionListener(){
                public void actionPerformed( java.awt.event.ActionEvent evt){
                          SetState();
    private static void SetState(){
        if( objMainProcess == null ) return;
        synchronized( objMainProcess ) {
            bChanged = true;
            try{
                objMainProcess.notify();
            }catch( IllegalMonitorStateException e ) {}
    private static boolean GetState() {
        if( objMainProcess == null ) return false;
        synchronized( objMainProcess ) {
            if( bChanged) {
                SendMessage();
                bChanged = false;
                return true;
            try {
                objMainProcess.wait();
            }catch( InterruptedException e ) {}
            return false;
    }

Thanks DrClap for your reply. Everything you said is right. It is not easy to make them alternate since SetState() could be called from different places where the state could be anything else but a status message. Like a GREETING message for example. It is a handshaking message but not a status message.
Again as you said, There is a reason I can't call sendMessage() inside setState().
The only way I was able to do it is by having a counter of the number of notifies that have been called. Every time notify() is called a counter is incremented. Now instead of just checking if "changed" flag is true, I also check if notify counter is greater than zero. If both true, I send the message. If "changed" flag is false, I check again if the notify counter is greater than zero, I send the message. This way it works, but it is kind of a patch than a good design fix. I am yet to find a good solution.
Thanks,
B.D.

Problem with threads running javaw

Hi,
Having a problem with multi thread programming using client server sockets. The program works find when starting the the application in a console using java muti.java , but when using javaw multi.java the program doesnt die and have to kill it in the task manager. The program doesnt display any of my gui error messages either when the server disconnect the client. all works find in a console. any advice on this as I havent been able to understand why this is happening? any comment would be appreciated.
troy.

troy,
Try and post a minimum code sample of your app which
does not work.
When using javaw, make sure you redirect the standard
error and standard output streams to file.
Graeme.Hi Graeme,
I dont understand what you mean by redirection to file? some of my code below.
The code works fine under a console, code is supposed to exit when the client (the other server )disconnects. the problem is that but the clientworker side of the code still works. which under console it doesnt.
public class Server{
ServerSocket aServerSocket;
Socket dianosticsSocket;
Socket nPortExpress;
ClientListener aClientListener;
LinkedList queue = new LinkedList();
int port = 0;
int clientPort = 0;
String clientName = null;
boolean serverAlive = true;
* Server constructor generates a server
* Socket and then starts a client threads.
* @param aPort      socket port of local machine.
public Server(int aPort, String aClientName, int aClientPort){
port = aPort;
clientName = aClientName;
clientPort = aClientPort;
try{
// create a new thread
aServerSocket = new ServerSocket(port) ;
// connect to the nPortExpress
aClientListener = new ClientListener(InetAddress.getByName(clientName), clientPort, queue,this);
// aClientListener.setDaemon(true);
aClientListener.start();
// start a dianostic port
DiagnosticsServer aDiagnosticsServer = new DiagnosticsServer(port,queue,aClientListener);
// System.out.println("Server is running on port " + port + "...");
// System.out.println("Connect to nPort");
catch(Exception e)
// System.out.println("ERROR: Server port " + port + " not available");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Server port " + port + " not available", JOptionPane.ERROR_MESSAGE);
serverAlive = false;
System.exit(1);
while(serverAlive&&aClientListener.hostSocket.isConnected()){
try{
// connect the client
Socket aClient = aServerSocket.accept();
//System.out.println("open client connection");
//System.out.println("client local: "+ aClient.getLocalAddress().toString());
// System.out.println("client localport: "+ aClient.getLocalPort());
// System.out.println("client : "+ aClient.getInetAddress().toString());
// System.out.println("client port: "+ aClient.getLocalPort());
// make a new client thread
ClientWorker clientThread = new ClientWorker(aClient, queue, aClientListener, false);
// start thread
clientThread.start();
catch(Exception e)
//System.out.println("ERROR: Client connection failure");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client connection failure", JOptionPane.ERROR_MESSAGE);
}// end while
} // end constructor Server
void serverExit(){
     JOptionPane.showMessageDialog(null, "Server ","ERROR: nPort Failure", JOptionPane.ERROR_MESSAGE);
     System.exit(1);
}// end class Server
*** connect to another server
public class ClientListener extends Thread{
InetAddress hostName;
int hostPort;
Socket hostSocket;
BufferedReader in;
PrintWriter out;
boolean loggedIn;
LinkedList queue;      // reference to Server queue
Server serverRef; // reference to main server
* ClientListener connects to the host server.
* @param aHostName is the name of the host eg server name or IP address.
* @param aHostPort is a port number of the host.
* @param aLoginName is the users login name.
public ClientListener(InetAddress aHostName, int aHostPort,LinkedList aQueue,Server aServer)      // reference to Server queue)
hostName = aHostName;
hostPort = aHostPort;
queue = aQueue;
serverRef = aServer;
// connect to the server
try{
hostSocket = new Socket(hostName, hostPort);
catch(IOException e){
//System.out.println("ERROR: Connection Host Failed");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort Failed", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} // end constructor ClientListener
** multi client connection server
ClientWorker(Socket aSocket,LinkedList aQueue, ClientListener aClientListener, boolean diagnostics){
queue = aQueue;
addToQueue(this);
client = aSocket;
clientRef = aClientListener;
aDiagnostic = diagnostics;
} // end constructor ClientWorker
* run method is the main loop of the server program
* in change of handle new client connection as well
* as handle all messages and errors.
public void run(){
boolean alive = true;
String aSubString = "";
in = null;
out = null;
loginName = "";
loggedIn = false;
while (alive && client.isConnected()&& clientRef.hostSocket.isConnected()){
try{
in = new BufferedReader(new InputStreamReader(client.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));
if(aDiagnostic){
out.println("WELCOME to diagnostics");
broadCastDia("Connect : diagnostics "+client.getInetAddress().toString());
out.flush();
else {
out.println("WELCOME to Troy's Server");
broadCastDia("Connect : client "+client.getInetAddress().toString());
     out.flush();
String line;
while(((line = in.readLine())!= null)){
StringTokenizer aStringToken = new StringTokenizer(line, " ");
if(!aDiagnostic){
broadCastDia(line);
clientRef.sendMessage(line); // send mesage out to netExpress
out.println(line);
out.flush();
else{
if(line.equals("GETIPS"))
getIPs();
else{
clientRef.sendMessage(line); // send mesage out to netExpress
out.println(line);
out.flush();
} // end while
catch(Exception e){
// System.out.println("ERROR:Client Connection reset");
                         JOptionPane.showMessageDialog(null, (e.toString()),"ERROR:Client Connection reset", JOptionPane.ERROR_MESSAGE);
try{
if(aDiagnostic){
broadCastDia("Disconnect : diagnostics "+client.getInetAddress().toString());
out.flush();
else {
broadCastDia("Disconnect : client "+client.getInetAddress().toString());
     out.flush();
// close the buffers and connection;
in.close();
out.close();
client.close();
// System.out.println("out");
// remove from list
removeThreadQueue(this);
alive = false;
catch(Exception e){
// System.out.println("ERROR: Client Connection reset failure");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client Connection reset failure", JOptionPane.ERROR_MESSAGE);
}// end while
} // end method run
* method run - Generates io stream for communicating with the server and
* starts the client gui. Run also parses the input commands from the server.
public void run(){
boolean alive = true;
try{
// begin to life the gui
// aGuiClient = new ClientGui(hostName.getHostName(), hostPort, loginName, this);
// aGuiClient.show();
in = new BufferedReader(new InputStreamReader(hostSocket.getInputStream()));
out = new PrintWriter(new OutputStreamWriter(hostSocket.getOutputStream()));
while (alive && hostSocket.isConnected()){
String line;
while(((line = in.readLine())!= null)){
System.out.println(line);
broadCast(line);
} // end while
} // end while
catch(Exception e){
//     System.out.println("ERRORa Connection to host reset");
JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort reset", JOptionPane.ERROR_MESSAGE);
try{
hostSocket.close();
     }catch(Exception a){
     JOptionPane.showMessageDialog(null, (a.toString()),"ERROR: Exception", JOptionPane.ERROR_MESSAGE);
alive = false;
System.exit(1);
} // end method run

Problem with threads and camera.

Hi everybody!
I've a problem with taking snapshot.
I would like to display a loading screen after it take snapshot ( sometimes i
have to wait few seconds after i took snapshot. Propably photo is being taken in time where i have to wait).
I was trying to use threads but i didn't succeed.
I made this code:
display.setCurrent(perform);
        new Thread(new Runnable(){
            public void run() {
                while((!performing.isShown()) && (backgroundCamera.isShown())){
                    Thread.yield();
                notifyAll();
        }).start();
        new Thread(new Runnable(){
            public void run() {
                try {
                    this.wait();
                } catch(Exception e) {
                    exceptionHandler(e);
                photo = camera.snapshot();
                display.setCurrent(displayPhoto);
        }).start();This code is sometimes showing performing screen but sometimes no.
I don't know why. In my opinion performing.isShown() method isn't working correctly.
Does anyone have some idea how to use threads here?

Hi,
I've finally managed to work this fine.
The code:
       Object o = new Object();
       display.setCurrent(perform);
        new Thread(new Runnable(){
            public void run() {
                while(!performing.isShown()){
                    Thread.yield();
               synchronized(o) {
                  o.notify();
        }).start();
        new Thread(new Runnable(){
            public void run() {
                try {
                    synchronized(o) {
                       o.wait(1);
                } catch(Exception e) {
                    exceptionHandler(e);
                photo = camera.snapshot();
                display.setCurrent(displayPhoto);
        }).start();

Problem with threads hanging

We have a problem where our application stops responding after a few days of usage. Things will for fine for a day or two, and then pretty quickly threads will start getting hung up, usually in places where they are allocating memory
We are running WebLogic 8.1 SP2 on Sun JDK 1.4.2_04 on Solaris 8 using the alternate threading model and the -server hotspot vm. We are running pretty much the same code that we had no problems with under WebLogic 6.1 SP4 and Sun JDK 1.3.1.
A thread dump usually shows that some or all of our execute threads are in the state "waiting for monitor entry" even though they are not currently waiting on any java locks. Here is a sample thread from the thread dump (we have ~120 threads so I don't want to post the full dump).
=============================================================================================
"ExecuteThread: '8' for queue: 'itgCrmWarExecutionQueue'" daemon prio=5 tid=0x005941d0 nid=0x2c waiting for monitor entry [c807f000..c807fc28]
at java.lang.String.substring(String.java:1446)
at java.lang.String.substring(String.java:1411)
at weblogic.servlet.internal.ServletRequestImpl.getRelativeUri(ServletRequestImpl.java:1872)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3492)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2585)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
=============================================================================================
String.java line 1446 for this jdk allocates a new String object, and all the other threads in this state also are creating new objects or arrays, etc.
We've done a pstack on this process when it's in this state, and the threads that are in the "waiting for monitor entry" that look like they're allocating memory are all waiting on the same lwp_mutex_lock with some allocation method that's calling into the native TwoGenerationCollectorPolicy.mem_allocate_work (see pstack output below for the same thread as in the thread dump above)
=============================================================================================
----------------- lwp# 44 / thread# 44 --------------------
ff31f364 lwp_mutex_lock (e3d70)
fee92384 __1cNObjectMonitorGenter26MpnGThread__v_ (5000, 525c, 5000, 50dc, 4800, 4af0) + 2d8
fee324d4 __1cSObjectSynchronizerKfast_enter6FnGHandle_pnJBasicLock_pnGThread__v_ (c807f65c, c807f7d4, 5941d0, 0, 35d654, fee328ec) + 68
fee32954 __1cQinstanceRefKlassZacquire_pending_list_lock6FpnJBasicLock__v_ (c807f7d4, ff170000, d4680000, 4491d4, fee1bc2c,
0) + 78
fee3167c __1cPVM_GC_OperationNdoit_prologue6M_i_ (c807f7bc, 4400, ff170000, 2d2b8, 4a6268, c807fa18) + 38
fee2e0b0 __1cIVMThreadHexecute6FpnMVM_Operation__v_ (c807f7bc, 963a8, 0, 0, 1, 0) + 90
fed2c2a4 __1cbCTwoGenerationCollectorPolicyRmem_allocate_work6MIii_pnIHeapWord__ (962c0, ff1c29ec, ff1c297c, ff131a26, 4800, 4998) + 160
fed22940 __1cNinstanceKlassRallocate_instance6MpnGThread__pnPinstanceOopDesc__ (ee009020, 5941d0, 15ca581, 3647f0, 4a6268, c807f8c8) + 180
fed34928 __1cLOptoRuntimeFnew_C6FpnMklassOopDesc_pnKJavaThread__v_ (ee009018, 5941d0, 0, 0, 0, 0) + 28
fa435a58 ???????? (ee009018, e86de, 15ca4de, 50dc, 5941d0, c807f9c8)
fb36f9a4 ???????? (0, d412ccd8, ee046c28, ff170000, 0, 0)
fad8b278 ???????? (ee046c28, d6000c90, ee046530, 8, db8e8450, c807f9e8)
fad62abc ???????? (d412ccd8, ee046530, d6000c90, ee3bfa38, 8, c807fa18)
fa4b3c38 ???????? (c807fb9c, 0, f2134700, fa415e50, 8, c807faa8)
fa40010c ???????? (c807fc28, c807fe90, a, ee9e1e20, 4, c807fb40)
fed5d48c __1cJJavaCallsLcall_helper6FpnJJavaValue_pnMmethodHandle_pnRJavaCallArguments_pnGThread__v_ (c807fe88, c807fcf0, c807fda8, 5941d0, 5941d0, c807fd00) + 27c
fee4b784 __1cJJavaCallsMcall_virtual6FpnJJavaValue_nLKlassHandle_nMsymbolHandle_4pnRJavaCallArguments_pnGThread__v_ (ff170000, 594778, c807fd9c, c807fd98, c807fda8, 5941d0) + 164
fee5e8dc __1cJJavaCallsMcall_virtual6FpnJJavaValue_nGHandle_nLKlassHandle_nMsymbolHandle_5pnGThread__v_ (c807fe88, c807fe84, c807fe7c, c807fe74, c807fe6c, 5941d0) + 6c
fee6fc74 __1cMthread_entry6FpnKJavaThread_pnGThread__v_ (5941d0, 5941d0, 838588, 594778, 306d10, fee69254) + 128
fee6927c __1cKJavaThreadDrun6M_v_ (5941d0, 2c, 40, 0, 40, 0) + 284
fee6575c _start   (5941d0, fa1a1600, 0, 0, 0, 0) + 134
ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
=============================================================================================
Also when it's having this problem, the "VM Thread" is always using a lot of processor time. We did a couple of pstacks today while it was having this problem, and this thread was stuck in the ONMethodSweeper.sweep for over 15 minutes when we finally killed the server.
From the thread dump:
"VM Thread" prio=5 tid=0x000e2d20 nid=0x2 runnable
From the first pstack:
=============================================================================================
----------------- lwp# 2 / thread# 2 --------------------
fed40c04 __1cXvirtual_call_RelocationIparse_ic6FrpnICodeBlob_rpC5rppnHoopDesc_pi_nNRelocIterator__ (42a2f4, fa5fa46d, ffffffff, fc4ffcb8, 42a2f4, 42a324) + 124
fed46318 __1cKCompiledIC2t5B6MpnKRelocation__v_ (42a2f0, fc4ffd24, fc4ffd4c, e802, 0, 6) + 38
fed90c38 __1cHnmethodVcleanup_inline_caches6M_v_ (fa5f7f88, fa608940, 1, 0, fa400000, 6) + 1ac
fede18b4 __1cONMethodSweeperFsweep6F_v_ (2cf38, 0, ffffffff, ff1cf1fc, ff1c66e8, fede1d44) + 1b0
fede1e6c __1cUSafepointSynchronizeFbegin6F_v_ (2cf38, ff1ba138, 5000, 50dc, 5000, 525c) + 248
feef1fd4 __1cIVMThreadEloop6M_v_ (4400, 4000, 4324, 4000, 42b0, 3800) + 3d4
feef1ae4 __1cIVMThreadDrun6M_v_ (e2d20, 2, 40, 0, 40, 0) + 8c
fee6575c _start   (e2d20, ff270200, 0, 0, 0, 0) + 134
ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
=============================================================================================
Second pstack
=============================================================================================
----------------- lwp# 2 / thread# 2 --------------------
fed41180 __1cXvirtual_call_RelocationIparse_ic6FrpnICodeBlob_rpC5rppnHoopDesc_pi_nNRelocIterator__ (0, ff1b9664, ffffffff, fc4ffcb8, a6f2cc, fc4ffbd0) + 6a0
fed46318 __1cKCompiledIC2t5B6MpnKRelocation__v_ (a6f2c8, fc4ffd24, fc4ffd4c, e802, 0, 6) + 38
fed90c38 __1cHnmethodVcleanup_inline_caches6M_v_ (faded4c8, fadf2c80, 1, 0, fa400000, 6) + 1ac
fede18b4 __1cONMethodSweeperFsweep6F_v_ (2cf38, 0, ffffffff, ff1cf1fc, ff1c66e8, fede1d44) + 1b0
fede1e6c __1cUSafepointSynchronizeFbegin6F_v_ (2cf38, ff1ba138, 5000, 50dc, 5000, 525c) + 248
feef1fd4 __1cIVMThreadEloop6M_v_ (4400, 4000, 4324, 4000, 42b0, 3800) + 3d4
feef1ae4 __1cIVMThreadDrun6M_v_ (e2d20, 2, 40, 0, 40, 0) + 8c
fee6575c _start   (e2d20, ff270200, 0, 0, 0, 0) + 134
ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
=============================================================================================
Has anyone ever seen anything like this? I'm trying to figure out if this is caused by something we're doing, or something relating to our environment and jvm options. Any ideas?

Thanks for the reply - I'm testing our app with the +UseConcMarkSweepGC now in our test environment to make sure it doesn't cause any problems there. Unfortunately the only place we've had this problem is on the production server, so it's extra difficult debugging this.
We're using the following memory options:
-ms512m -mx512m -XX:NewSize=128m -XX:PermSize=192m -XX:MaxNewSize=128m -XX:MaxPermSize=192m -XX:SurvivorRatio=8and the following debugging options, as we've also been seeing OutOfMemoryErrors ( see http://forum.java.sun.com/thread.jsp?forum=37&thread=522354&tstart=45&trange=15 )
-verbosegc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGCBTW, which c++filt version and options are you using? Our Solaris boxes only seem to have the GNU version installed. I was trying to run that on some of the other stack traces and wasn't getting anywhere, and didn't know if because it was GNU version wouldn't work on something compiled with the Sun compiler.
Thanks!
--Andy

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