Java Event Handling in JSP Pages

Dear All:
This is what I wanna do. when user enters text in my <input type="text" ... > in my JSP page, I want to take this user entered data and convert it in another language simultaneously as the user is inputting text in another textarea.
Right now the only choice I have is onChange="convert()" Javascript function.
But I dont want to use Javascript as I already have a Java class which does that for the Swing GUI client.
Is their a way i can embed java for event handling in jsp.
thanks,
Chetan

only if you use an applet, javascript, etc.
remember, jsp is server-side, not client-side
what the client sees is html or whatever (i.e. static content)

Similar Messages

How to Generate a Java file for a JSP Page

Hi ,
I am using weblogic11 .
I am working on a JSP page which nearly consists of 4000 lines of code.
I need to debug the file , but weblogic server is not generating the java file for the JSP pages .
Please let me know how can i genertae Java file for the jsp pages ??

JSPs are compiled into servlets automatically and those classes are stored in WEB-INF/classes folder. Servlet engine handles servlets.

How i can make my own connection in java source of a jsp page

How i can make my own connection in java source of a jsp page (How to get connection from JNDI datasource address) ?
imagine that i have a rowset in a web page , now i want to do some operation using
plain JDBC , so i will need a connection object.
I tried to get one of my rowsets connection but it return null ?
what is best way to retrive a connection from JNDI datasource that we define for our project?
for example if i have
myRowSet.setDataSourceName("java:comp/env/jdbc/be");
in web page constructor
now i want a pure connection from the same datasource ? JNDI
Thank you

It is not hard to get your own connection from datasource.
in your case you need to do like the the following code.
i provide sample to show you how to catch the exception and create an statement .
Connection con =null;
try{
InitialContext ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("java:comp/env/jdbc/be");
con = ds.getConnection();
java.sql.Statement st =con.createStatement();
}catch(SQLException sqlex){
sqlex.printStackTrace();
sqlex.getNextException().printStackTrace();
catch(NamingException nex){
nex.printStackTrace();
hth
Masoud kalali

Opening a Java Window from a jsp page on the client side

Hi all,
Thanks in advance to all who could help me for this problem.
I've written some jsp pages. In one of them, I open a new Java Window,
which is a simple Java Frame. If I test this directly on the Tomcat
server, everything works well.
But when I call the jsp page through a web browser of a distant client
(normal use), and when I want to see the java window, no window pops
up. It appears that the Java Window pops up on the server, and not on
the client side, which is what I wanted.
Could someone tell me how to make the Java frames appear on the client
side ? (Is it linked to the code or to the configuration of Tomcat ?)
Thanks in advance,
Alexis.

JSP always run on the server. On the client you only see the results.
But you can use applets on the client side: http://java.sun.com/docs/books/tutorial/uiswing/components/applet.html

Tomcat 6 Calling a Java Servlet from a JSP Page

Below is a very simple JSP Page that calls a Java Servlet. The question is given Tomcat security constraints, is it possible to call a servlet from a JSP and get the correct output without getting an error message? If so, how would you code the web.xml file?
c:\apache-tomcat-6.0.18
Under conf
catalina
localhost
HelloWorldExample.xml is directly under localhost
The application would have this directory structure:
webapps
HelloWorldExample
hello.jsp is directly under HelloWorldExample
Under HelloWorldExample
src
WEB-INF
classes
Under classes
jservlets
HelloWorld.java is in src folder
HelloWorld.class is in jservlets folder
HelloWorldExample.xml
<Context path="/HelloWorldExample" docBase="HelloWorldExample" debug="0"
      reloadable="true" crossContext="true">
</Context>**************************
hello.jsp
<HTML>
<HEAD>
<TITLE>Hello</TITLE>
</HEAD>
<BODY>
<FONT SIZE="4">
<P>
Please enter your name:
<FORM
   METHOD="Post"
   ACTION="servlet/jservlets.HelloWorld">
<TABLE BORDER="3" CELLPADDING="1" WIDTH="100%" ALIGN="CENTER">
<TR>
    <TD><B>Name:</B></TD>
    <TD><INPUT TYPE="text" NAME="Name" VALUE="" SIZE="65"> </TD>
</TR>
</TABLE>
<P>
<INPUT TYPE="SUBMIT" VALUE="Submit">
</FORM>
</FONT>
</BODY>
</HTML>******************
HelloWorld.java
package jservlets;
import java.io.*;
import java.util.Date;
import java.util.*;
import java.text.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HelloWorld extends HttpServlet
   PrintWriter out;
   PrintWriter err;
   String strName;
public void displayMessage(HttpServletRequest request, HttpServletResponse response)
      throws Exception
         try
            if (!strName.equals("") && strName != null)
               out.println("Hello " + strName + "" + "<P>");
                out.println("Hello World" + "<P>");
            else
                out.println("Hello World" + "<P>");
        catch (Exception e)
            out.println("Exception: Could not display message." + "<P>");
            err.println (e.getMessage () ) ;
            out.println("<P>");
public void doPost(HttpServletRequest request, HttpServletResponse response)
           throws ServletException, IOException
      try
           response.setContentType("text/html");
           out = response.getWriter();
           err = response.getWriter();
           strName = request.getParameter("Name").trim();
           out.println("<html><head><title>");
          out.println("</title></head><body>");
           out.println("<FORM");
           out.println("METHOD=POST");
           out.println("ACTION=http://localhost:8080/HelloWorldExample/hello.jsp>");
         out.println("<TABLE ALIGN='RIGHT'>");
         out.println("<TR>");
         out.println("<TD>");
           out.println("<INPUT TYPE=\"SUBMIT\" VALUE=\"Hello World Page\";>");
           out.println("</INPUT>");
          out.println("</TD>");
         out.println("</TR>");
         out.println("</TABLE>");
         out.println("</FORM>");
         out.println("<BR CLEAR='all'>");
           out.println("<P>");
           displayMessage(request, response);
           out.close();
         out.println("</body></html>");
       catch(Throwable e)
          e.printStackTrace();
      public void doGet(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException
         doPost(request, response);
web.xml
<servlet>
      <servlet-name>HelloWorld</servlet-name>
      <servlet-class>jservlets.HelloWorld</servlet-class>
</servlet>
<servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>/servlet/HelloWorld</url-pattern>
</servlet-mapping>      ******************************
HelloWorld.java can be compiled by using javac.
Once compiled, HelloWorld.class would be moved to the jservlets folder.
FYI, coding the above url-pattern results in:
HTTP Status 404
The requested resource (/HelloWorldExample/servlet/jservlets.HelloWorld) is not available
The following url-pattern in the web.xml file permits the servlet to be executed but results in a null pointer exception:
<servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>/ </url-pattern>
</servlet-mapping>      **************************************************
Robin

This problem was resolved.
In hello.jsp
ACTION="servlet/jservlets.HelloWorld">
was replaced with
ACTION="servlet/HelloWorld">
Robin

Java.lang.ClassCastException in JSP page

My JSP page:
<%@page contentType="text/html"%>
<HTML>
<HEAD>
<TITLE> JDBC Servlet/JSP Example </TITLE>
</HEAD>
<BODY>
<%@ page import="myBeans.memoryBean" %>
<%@ page import="java.util.Vector" %>
<H1> JDBC Servlet/JSP Example </H1>
<H2> <%= session.getValue("message") %>
</H2>
<UL>
<%
     Vector vData = (Vector) session.getValue("res");
     myBeans.memoryBean mb;
     Object o;
     for (Enumeration e = vData.elements() ; e.hasMoreElements() ;) {
          o = e.nextElement();
          mb = (myBeans.memoryBean) o;
%>
    <LI> <%= o.getClass().getName() %>
<%      } // end for
%>
</UL>
</BODY>
</HTML>Notice that I don't even use the object I cast but I still get the error message:
Exception:
java.lang.ClassCastException
     at _memory._search._jspService(_search.java:66)
     at oracle.jsp.runtime.HttpJsp.service(HttpJsp.java)
     at oracle.jsp.app.JspApplication.dispatchRequest(JspApplication.java)
     at oracle.jsp.JspServlet.doDispatch(JspServlet.java)
     at oracle.jsp.JspServlet.internalService(JspServlet.java)
     at oracle.jsp.JspServlet.service(JspServlet.java)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:588)
     at org.apache.jserv.JServConnection.processRequest(JServConnection.java:314)
     at org.apache.jserv.JServConnection.run(JServConnection.java:188)
     at java.lang.Thread.run(Thread.java:534)When I comment out the line that castes my object my browser displays:
JDBC Servlet/JSP Example
Records Found:
    * myBeans.memoryBean
    * myBeans.memoryBean
    * myBeans.memoryBean Notice that the three objects that are returned are exactly the type that I caste to.
Also, I did a getClass().getClassLoader() when I create the objects in my servlet code and again on the JSP pages for each object I pull out of the vector and the class loader matched.
I even changed the package on my bean class and recompiled everything to make sure it wasn't a old .class file floating around.
Could this have something to do with my classpath or where my classes are being placed? I found a similar problem here: http://forum.java.sun.com/thread.jsp?forum=33&thread=380437&start=0&range=15&hilite=false&q=
but the explanation of what was done wasn't clear
Anyone have any idea what's going on here?
I am using:
Oracle 9i
Oracle HTTP Server Powered by Apache/1.3.12 (Unix)
ApacheJServ/1.1
Thanks in advance.
- Linus

Is ti at all possible that you have another jar / zip file with the same class file in it, seemingly away from the Server classpath ? In which case this could happen even though logically it shouldn't !!!

Call to pl/sql from java event-handler

How can I call pl/sql procedure or function from java-script event handler
Thanks,
Anna

Anna,
You cannot call any arbitrary PLSQL code from the forms, only "standard"/custom event handlers can be called through do_event Javascript fuction, syntax :
do_event(this.form,this.name,1,'ON_CLICK,'');
where:
1 - button intstance, if you have more than one instance of the same button on the screen this should be 2,3,4.....
'ON_CLICK' - is the predefined event type
'' - the last argument is any user defined string which will passed down to the PLSQL event handler.
Thanks,
Dmitry
null

Cannot compile java beans in my jsp page

Hi all
I have created jsp pages which contains java beans. Now its working fine on my machine(XP OS) but when i put it on windows 2000 server it gives the following error:
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: Unable to compile class for JSP
An error occurred at line: -1 in the jsp file: null
Generated servlet error:
[javac] Since fork is true, ignoring compiler setting.
[javac] Compiling 1 source file
[javac] Since fork is true, ignoring compiler setting.
     at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:130)
     at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:293)
     at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:353)
     at org.apache.jasper.compiler.Compiler.compile(Compiler.java:370)
     at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:473)
     at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:190)
     at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:295)
     at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:256)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
     at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2415)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
     at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:171)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
     at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
     at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
     at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
     at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:223)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:594)
     at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:392)
     at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:565)
     at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:619)
     at java.lang.Thread.run(Unknown Source)
please help

Ok, jsp pages to not contain java beans, java beans are separate classes which you access from a jsp.
Is this what you have done, i.e. created classes under classes/yourPackage ?
If so, you do not need to recompile the class when you move it, you can move the pre-compiled class file.
In terms of your error, I have no idea, but it looks interesting!!
The most likely cause is a difference in the JDK versions you are running on the different machines. If the JDK on windows 2000 is older, you may need to upgrade it.

Loading Java Class File in JSP page

I'm trying to load a java class file from a jsp page.
(e.g. MyFile.java <-- Source "MyFile.class<--Class file of MyFile.java")
jsp page
<%@ include file = "MyFile.class" %>
<HTML> // HTML Tags are here
MyFile.java
A normal java source file that has "public static void main" in it.
My jsp page can display it's contents, 'except' for showing e.g. "1235%%215648%%public%%$$@##" through out the page...
My guess is that it can't display my java class file..
Can anyone please help me solve this problem of mine ?
Thanks in advance : )
Yours Sincerely,
RainbowEnergies

This is my JSP file.
<HTML>
<HEAD>
<TITLE>Activity Games</TITLE>
</HEAD>
<%
String name = "";
String id = "";
name = session.getAttribute("name").toString();
session.setAttribute("name",name);
id = session.getAttribute("id").toString();
session.setAttribute("id",id);
%>
<BODY bgcolor="#cc99ff" text="#000000" link="#E3E3E3" vlink="#CCCCCC" alink="#FF0000">
<H3><%=name%>, you have enter Activity Games</H3>
<%@ page import="Games.Lufia.*" %>
<%Lufia lufia = new Lufia();%>
</BODY>
</HTML>
After I execute...
An error occurred at line: 18 in the jsp file: /jsp/ActivityGames.jsp
error: File C:\Program Files\Apache Tomcat 4.0\webapps\website\WEB-INF\classes\Games\Lufia\Lufia.class does not contain type Games.Lufia.Lufia as expected, but type Lufia. Please remove the file, or make sure it appears in the correct subdirectory of the class path.
Generated servlet error:
C:\Program Files\Apache Tomcat 4.0\work\Standalone\localhost\website\jsp\ActivityGames$jsp.java:85: Class Games.Lufia.Lufia not found.
Lufia lufia = new Lufia();
But if I comment this out....
This is my JSP file.
<HTML>
<HEAD>
<TITLE>Activity Games</TITLE>
</HEAD>
<%
String name = "";
String id = "";
name = session.getAttribute("name").toString();
session.setAttribute("name",name);
id = session.getAttribute("id").toString();
session.setAttribute("id",id);
%>
<BODY bgcolor="#cc99ff" text="#000000" link="#E3E3E3" vlink="#CCCCCC" alink="#FF0000">
<H3><%=name%>, you have enter Activity Games</H3>
<%@ page import="Games.Lufia.*" %>
<%//Lufia lufia = new Lufia();%> <--- comment this out.... (HERE)
</BODY>
</HTML>
The page shows but did not run my java class file..
Thanks again for trying to help me solve this problem of mine. : - )
Regards,
RainbowEnergies

Recompilation of java class invalidates taglib jsp page?

Hi everyone,
          I have a JSP page which calls a custom tag library. On freshly compiling
          everything and
          calling the JSP page from a browser for the first time the output is as
          expected.
          However when ever I recompile one of the classes that get called anywhere in
          the tag
          library call the tag no longer works (internal error from the server).
          To get it to work I have to change the jsp page so that it recompiles.
          Weblogic server 5.1 (no service patches yet) running on NT server SP6a.
          Any ideas?
          MTIA
          Craig


p.s
          The following errors are in the log file.
          Is this another class casting problem?
          Does any one have any explanations?
          Ta
          Craig
          <ServletContext-General> Servlet failed with Exception
          javax.servlet.ServletException: runtime failure in custom tag 'MyTag'
          at jsp_servlet._taglib._jspService(_taglib.java:89)
          at weblogic.servlet.jsp.JspBase.service(JspBase.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java
          , Compiled Code)
          at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContext
          Manager.java, Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java,
          Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.execute(MuxableSocketHTTP.java,
          Compiled Code)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java, Compiled Code)
          <ServletContext-General> root cause of ServletException
          java.lang.ClassCastException: com.bt.db.MyTag
          at jsp_servlet._taglib._jspService(_taglib.java:77)
          at weblogic.servlet.jsp.JspBase.service(JspBase.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java
          , Compiled Code)
          at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletContextImpl.invokeServlet(ServletContextImp
          l.java, Compiled Code)
          at
          weblogic.servlet.internal.ServletContextManager.invokeServlet(ServletContext
          Manager.java, Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(MuxableSocketHTTP.java,
          Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.execute(MuxableSocketHTTP.java,
          Compiled Code)
          at weblogic.kernel.ExecuteThread.run(ExecuteThread.java, Compiled Code)
          "crg" <[email protected]> wrote in message
          news:[email protected]...
          > Hi everyone,
          >
          > I have a JSP page which calls a custom tag library. On freshly compiling
          > everything and
          > calling the JSP page from a browser for the first time the output is as
          > expected.
          > However when ever I recompile one of the classes that get called anywhere
          in
          > the tag
          > library call the tag no longer works (internal error from the server).
          > To get it to work I have to change the jsp page so that it recompiles.
          >
          > Weblogic server 5.1 (no service patches yet) running on NT server SP6a.
          >
          > Any ideas?
          > MTIA
          >
          > Craig
          >
          >
          >
          >

Using Java Objects in my JSP page... objects are in a different directory

Hi,
I would like to call and use an object from a JSP page. The java object is in one directory, the jsp is in another. When I call my object, I get a JSP error that says it can't find the object and lists the directory name as part of the file.
For example, here are my two files:
/java/MyObject.class
/web/page.jsp
When I make the call to new MyObject(), I get an error message saying _web.MyObject cannot be found. Any ideas on this?
Thanks!

Okay, I figured it out. In case anyone else needs it, here is what I needed to do.
1) I created my object in a package. The JSP page was looking for the object in _dir directory because a package wasn't specified. I created a subdirectory in one of the directories in my classpath and named it the same thing that the package was named.
2) Import the package
3) Make sure all methods in the classes are public, since only public methods can be accessed from outside the package.
Thanks for the help, it got me going in the right direction.

Java Mail Problems within JSP Page

Hi all,
I'm encountering the following problem. I hava a jsp file named common.jsp with holds all common functions like write header and footer and also a send mail function. i include this page in all my other jsp pages. In the signup page - i need to send out 2 emails, one to the administrator and the other to the user who signed up. so i call that send mail function twice. the first call works(meaning it sends out the email) but the second call gives me a No SMTP Provider exception. Can anyone help me with this.
thx a bunch
p.s: i have included the sendEmail Function below
public void sendEmail(String emailServer, String sEmail, String sName, String rEmail,
     String subject, String strmsg) throws Exception {
     java.util.Properties props = new java.util.Properties();
     props.put("mail.host", emailServer);
     javax.mail.Session mailConn = javax.mail.Session.getInstance(props, null);
     javax.mail.Message msg = new javax.mail.internet.MimeMessage(mailConn);
     javax.mail.Address sender = new javax.mail.internet.InternetAddress(sEmail, sName);
     javax.mail.Address receiver = new javax.mail.internet.InternetAddress(rEmail);
     msg.setContent(strmsg,"text/html");
     msg.setFrom(sender);
     msg.setRecipient(javax.mail.Message.RecipientType.TO, receiver);
     msg.setSubject(subject);
     javax.mail.Transport.send(msg);
}

This is what i use and it works just fine
import java.io.*;
import java.net.InetAddress;
import java.util.Properties;
import java.util.Date;
import javax.mail.*;
import javax.mail.internet.*;
public class sendMail {
public sendMail(String To,String Subject,String message) {
String to = To, subject = Subject, from = null,
          cc = null, bcc = null, url = null;
     String protocol = null, host = null, user = null, password = null;
     boolean debug = false;
     try{
Properties props = System.getProperties();
     Session session = Session.getDefaultInstance(props, null);
     Message msg = new MimeMessage(session);
     if (debug)
          session.setDebug(true);
msg.setFrom(new InternetAddress("[email protected]"));
     msg.setRecipients(Message.RecipientType.TO,
                         InternetAddress.parse(to, false));
     msg.setSubject(subject);
msg.setText(message);
     msg.setHeader("Mail","test.com");
     msg.setSentDate(new Date());
     Transport.send(msg);
     System.out.println("\nMail was sent successfully.");
     } catch (Exception e) {
     e.printStackTrace();

Extend a Java Class Inside a JSP Page?

Hello all. I'm not sure if I am thinking about this right. But what I have is a BaseClass that all of my other classes Extend. I'm inside a JSP page and want to use all of the functionality of that BaseClass. Is there anyway I can EXTEND A CLASS INSIDE A JSP PAGE or am I smoking crack?

Its an attribute of the page directive
"extends="package.class"
The fully qualified name of the superclass of the Java class this JSP page will be compiled to. Use this attribute cautiously, as it can limit the JSP container's ability to provide a specialized superclass that improves the quality of the compiled class. "
http://java.sun.com/products/jsp/tags/12/syntaxref1210.html#15653

How can i apply this java program for a jsp page?

import java.io.*;
import java.util.*;
public class FileProcessing
//create a vector container for the input variables
     Vector variables = new Vector();
//create a vector container for the constants
     Vector constants = new Vector();
/*create a string expression container for the equation
     as read from the file */
     String expression = " ";
//create double result container for the final result
     double result = 0;
     public boolean processFile(String filename,String delim)
      //index for values vector
          int num_values = 0;
      //index for constants vector
          int num_constants = 0;
      //current line being read from the external file.
          String curline = " ";
      //start reading from the external file
          try
               FileReader fr = new FileReader(filename);
               BufferedReader br = new BufferedReader(fr);
               while(true)
                    curline = br.readLine();
                    if(curline == null)
                         break;
                //determine the type of current interaction
                    boolean variable = curline.startsWith("input");
                    boolean constant = curline.startsWith("constant");
                    boolean equation = curline.startsWith("equation");
                    boolean output = curline.startsWith("result");
               //on input variables
                    if(variable)
                      StringTokenizer st = new StringTokenizer(curline,delim);
                      int num = st.countTokens();
                      int count=0;
                      while(st.hasMoreTokens())
                           String temp = st.nextToken();
                           if(count==1)
                                byte b[]= new byte[100];
                                System.out.println(temp);
                                System.in.read(b);
                                String inputval = (new String(b)).trim();
                                variables.add(num_values,inputval);
                                num_values++;
                           count++;
                    // on constant values
                    if(constant)
                         StringTokenizer st = new StringTokenizer(curline,delim);
                         int num = st.countTokens();
                         int count = 0;
                         while(st.hasMoreTokens())
                              String temp = st.nextToken();
                              if(count==1)
                                   byte b[]= new byte[100];
                                   System.out.println(temp);
                                   System.in.read(b);
                                   String cons = (new String(b)).trim();
                                   constants.add(num_constants,cons);
                                   num_constants++;
                              count++;
                    // on equation
                    if(equation)
                         StringTokenizer st = new StringTokenizer(curline,delim);
                         int num = st.countTokens();
                         int count = 0;
                         while(st.hasMoreTokens())
                              String temp = st.nextToken();
                              if(count==2)
                                   this.expression = temp;
                              count++;
          // now we are ready to evaluate the expression
                   if(output)
                      org.nfunk.jep.JEP myparser= new org.nfunk.jep.JEP();
                      myparser.setAllowAssignment(true);
                      for(int i=1;i<variables.size()+1;i++)
                         String name = "arg"+Integer.toString(i);
                         myparser.addVariable(name,new Double(variables.get(i-1)
                                            .toString()).doubleValue());
                      for(int i=1;i<constants.size()+1;i++)
                           String name = "arg" +Integer.
                                     toString(i+variables.size());
                           myparser.addConstant(name,new Double(constants.get(i-1).toString()));
               //output is obtained as follows
                      myparser.parseExpression(expression);
                      result = myparser.getValue();
                      System.out.println("Assay value: "+result);
          catch(Exception e)
               System.out.println(e.toString());
          return true;
     public static void main(String[] args)
          FileProcessing fp = new FileProcessing();
          fp.processFile("input.eqn",":");
}//my text file name is: "input.eqn" (given below)
input:Enter Value1:arg1
input:Enter Value2:arg2
input:Enter Value3:arg3
constant:arg4
constant:arg5
Equation:arg1+arg2+arg3
result:

how can i apply this java program for a jsp pagewhy do you want to do this ?
Your program reads from a file on the disk and formats based on a patterm.
Jsp is not intended for such stuff.
ram.

How can i call java class file in jsp page

Hai,
i wants to call .class file in jsp page.
my class file is in C:\jsdk\bin.
Thanks

I'm not entirely sure what you mean by "calling a class file", but I'm going to assume that you want to do something like the following in your page:
<%
MyClass myClass = new MyClass();
myClass.someMethod();
%>etc
If that's the case, then all you have to do is make sure that the class is in the servlet engine's classpath. You'll probably also need to include an appropriate import statement at the top of the page.
Hope that helps.

Java Event Handling in JSP Pages

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