java bean program

From:
mpriya2050@gmail.com
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 4 Sep 2008 02:07:15 -0700 (PDT)
Message-ID:
<9e9918a2-9474-48ea-996b-5119dc1446dd@b2g2000prf.googlegroups.com>
Error in java bean program...
when i run the above program i got a following error..please give the
suggestion to run the program ...... some times i got an empty page
also...

thanks
by
mohana

Java Bean program

package test;
import java.util.*;
import java.io.Serializable;
import java.sql.*;
import java.io.*;
public class FindAuthor implements Serializable {
    public String url,authorName,driverName,authorId;
    public Vector result;
    public void setUrl(String url)
    {
        if(url!=null)
            this.url=url;
    }
     public void setAuthorId(String authorId)
     {
         if(authorId!=null)
             this.authorId=authorId;
     }
      public void setDriverName(String driverName)

      {
          if(driverName!=null)
          this.driverName = driverName;
      }
      public String getAuthorId()
      {
          return(this.authorId);
      }
      public Vector getResult()
      {
          Vector v=new Vector();
          try
          {
           Class.forName(driverName);
          }
          catch(ClassNotFoundException e)
          {
              System.out.println(e);
          }
          try
          {
           Connection

con=DriverManager.getConnection(url,"sa","sa");
           PreparedStatement

st=con.prepareStatement("select * from jeas1 where

auid=?");
           st.setString(1,authorId);
           ResultSet rs=st.executeQuery();
              if(rs.next())
              {
                  v.addElement("auname");
                  v.addElement("address");
                  v.addElement("city");
                  v.addElement("state");
                  v.addElement("zip");
              }
      }
      catch(SQLException ex)
      {
          ex.printStackTrace();
      }
            this.result = v;
            return result;

      }
}

Getauthor name.jsp(jsp program)

<html>
<%@ page import="java.util.*" %>
<%@ page import="test.FindAuthor" %>

<jsp:useBean id="FA" scope="application"

class="test.FindAuthor" />
<jsp:setProperty name="FA" property="*" />

        <body>
        <%
        Vector v =(Vector)FA.getResult();
        Enumeration enum1=v.elements();
        while(enum1.hasMoreElements())
        {
        out.println("Author Name:"+enum1.nextElement());
        %>
        <br>
        <%
        out.println("Address:" +enum1.nextElement());
        %>
        <br>
        <%
        out.println("City:"+enum1.nextElement());
        %>
        <br>
        <%
        out.println("State:"+enum1.nextElement());
        %>
        <br>
        <%
        out.println("ZIP:"+enum1.nextElement());
        }
        %>
    </body>
</html>

Html program

<html>
    <body>
    <form action="/WebApplication12/Getauthorname.jsp"

method="get">
        AuthorId:<input type="text" name="auid"><br>
        URL :<input type="text" name="url"><br>
        DriverName:<input type="text" name="DN"><br>
        <input type="submit" value="Submit">
    </form>
</body>
</html>

Error page

type Exception report

message

description The server encountered an internal error ()

that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception

occurred processing JSP page /Getauthorname.jsp at line

10

7:
8: <body>
9: <%
10: Vector v =(Vector)FA.getResult();
11: Enumeration enum1=v.elements();
12: while(enum1.hasMoreElements())
13: {

Stacktrace:

org.apache.jasper.servlet.JspServletWrapper.handleJspE

xception(JspServletWrapper.java:524)

org.apache.jasper.servlet.JspServletWrapper.service(Jsp

ServletWrapper.java:435)

org.apache.jasper.servlet.JspServlet.serviceJspFile(JspSe

rvlet.java:320)

org.apache.jasper.servlet.JspServlet.service(JspServlet.ja

va:266)

javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

org.netbeans.modules.web.monitor.server.MonitorFilter.do

Filter(MonitorFilter.java:390)

root cause

java.lang.NullPointerException
    java.lang.Class.forName0(Native Method)
    java.lang.Class.forName(Class.java:169)
    test.FindAuthor.getResult(FindAuthor.java:35)

org.apache.jsp.Getauthorname_jsp._jspService(Getauthor

name_jsp.java:74)

org.apache.jasper.runtime.HttpJspBase.service(HttpJspBa

se.java:70)

javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

org.apache.jasper.servlet.JspServletWrapper.service(Jsp

ServletWrapper.java:393)

org.apache.jasper.servlet.JspServlet.serviceJspFile(JspSe

rvlet.java:320)

org.apache.jasper.servlet.JspServlet.service(JspServlet.ja

va:266)

javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

org.netbeans.modules.web.monitor.server.MonitorFilter.do

Filter(MonitorFilter.java:390)

note The full stack trace of the root cause is available in

the Apache Tomcat/6.0.14 logs.

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