No. of javabeans in jsp pages

Hi,
If i am having 180-200 textfield in a jsp page and i want to submit the whole data in database table then how many beans should be used to improve the performance . Can it be done using only single bean and if not then what should be the criteria to split it in multiple bean ?

I am not sure if I understand correctly, but do you have 180-200 different text fields? If so, of course you can do it in one bean. I would suggest either passing in an ArrayList or some sort of similar structure ... maybe just an array ... and have the bean do the work. I can't imagine a problem that would 'require' you to use multiple beans for one operation. Your SQL statement will probably be very long, but regardless, one bean should be able to handle it without a problem.
dan

Similar Messages

Using JavaBeans in a JSP Page

I wan't to know the advantages and disadvantages of using JavaBeans in a JSP page.
Like for example general traditional approach for a database connection
is to create a connection and access the database from that and close the connection
at the end of the page, instead of the If I use a common connection bean for making connections,
is that suggestable and then when should i close the connection then.
One good application of JavaBeans is using a Set and Get methods for form fields in
a registration form to get back the values.
So may i know how best can we use the JavaBeans other than this application.
ThanX in advance,
kiran
[email protected]

I believe putting processing and query code in the JavaBean was one of the reasons for putting JavaBeans support in JSP in the first place. The original idea was to use the setXXX methods to populate the bean's data from the posted form, then do the processing (or database query), then use the getXXX methods to display the bean's data.
Efficiency-wise, it's exactly the same as putting all the code in-line in the JSP page (actually, it might be a bit slower, because of the reflection required to do it.) Code-wise though, it makes the JSP easier to read.
Of course, we have EJBs now too, which tie very closely and can match database queries almost one-to-one, one way to incorporate these is inside the JavaBean you reference from the JSP, another way from a servlet you redirect the JSP to, etc...

Scope of a JavaBean in a JSP page

Is there any default scope for a Java Bean in a JSP page. If so, wht is it. IF the bean is assigned a "application scope", is it that the system resources are allocated to the bean.

The default scope of javaBean is page
and you can also change it to
1.page
The bean exists for the life of the page
2.request
The bean's internal information is stored in the ServletRequest object
3.session
The bean is available to all of your JSP pages for the entire session
4.application
The bean will remain until the application is reloaded or the sever is restarted
From Timothy

Can't use relative paths in jsp pages or javabeans

Hi everyone,
Can someone please help me with this little problem.
When I want to use in a JSP page the object 'FileReadInput' to read in a file, it can't find when I only give the filename. The target file and source file are in the same directory so I would expect if I only give the filename, it will automatically search in the current directory. But when I give the complete absolute path, everything works fine. Is it possible to use relative paths in a jsp or javabean file?
By the way, I am working with JDeveloper from Oracle. (maybe that has something to do with my problem)
Can someone help me???
Thx

My dear friend,
It will not work at all. coz, for any jsp file, ur application server will create a .java file and then .class file in a directory other than the directory where ur .jsp file present. that's why, ur file to be read can't be found. that's why use the following.
String path=getServletConfig().getServletContext().getRealPath("/")+File.seperator+"yourfilename";

Populating combobox in jsp page from javabean using jsp:getProperty tag

hi,
i am new to jsp, so i don;t know how to populate a combobox in jsp page with productid attribute from a javabean called Bid . i want to have a code to automatically populating combobox using the attribute value from javabean.
please reply me.
<jsp:useBean id="bidpageid" class="RFPSOFTWARE.Bid" scope="session" />
<jsp:setProperty name="bidpageid" property="*"/>
<table width="50%" align="center" border="0">
   <tr>
    <td width="30%" align="left"><h4><b><label>Date (dd/mm/yyyy) </label></b></h4> </td>
    <td><input type="text" name="date" size="11" maxlength="10" readonly="readonly" value="<jsp:getProperty name="bidpageid" property="date"/>" > </td>
</tr>
<tr> <td > </td> </tr>
<tr>
    <td width="30%" align="left"><h4><b><label>ProductId </label></b></h4> </td>
    <td><select name="productid" tabindex="1" size="1" >
      <option value="<jsp:getProperty name=bidpageid" />Sachin</option>
      <option value="Hello">Vishal</option>
    </select></td>
</tr> and the javabean for Bid is as follow :
import java.util.Date;
import RFPSOFTWARE.Product;
public class Bid{
private Product product;
private Integer bid_id;
private String description;
private Date date= new Date();
public Integer getBid_id() {
return bid_id;
public Date getDate() {
return date;
public String getDescription() {
return description;
public Product getProduct() {
return product;
public void setBid_id(Integer bid_id) {
this.bid_id = bid_id;
public void setDate(Date date) {
this.date = date;
public void setDescription(String description) {
this.description = description;
public void setProduct(Product product) {
this.product = product;
}

No Sir,
I think I did not explained clearly.what I try to say is I dont want to use JSTL.I am using only Scriptlets only.I can able to receive the values from the database to the resultset.But I could not populate it in Combobox.
My code is :
<tr>
<td width="22%"><font color="#000000"><strong>Assign To Engineer</strong></font></td>
<td width="78%">
     <select NAME="Name" size="1">
<option><%=Username%></option>
</select> </td>
</tr>
in HTML
and in Scriptlets:
ps1 = con.prepareStatement
          ("SELECT Username FROM Users");
          rs2=ps1.executeQuery();
          System.out.println("SECOND Succesfully Executed");
          while(rs2.next())
               System.out.println("Coming inside rs2.next loop to process");
               Username=rs2.getString("Username");
               System.out.println("Success");
               System.out.println("The value retrieved from UsersTable Username is:"+Username);
In the server(Jboss console) I can able to display the username but I could not populate it in the Combobox .
Can you now suggest some changes in my code,Please..
Thanks a lot
With kind Regds
Satheesh

JavaBeans and Tags in JSP pages

I have a java package and some code that already works but I need to "Webify" it. I have heard the words Tag Libraries and Beans to use with JSP pages instead of writing out the java code in the page. I have read the tutorial on Tag Libraries and it still makes no sense. I need some kind of beginners guide and instruction. I already have the java in the .jar file and have Tomcat setup. I know I need to make a tag library and stuff, but beyond that I'm a bit lost. I'm just not sure where to put what. Also, I did do a practice JSP page but it won't automatically find the jar file - they are in the WEB-INF/lib directory. I actually have to set the CLASSPATH separately by doing export CLASSPATH=.... which I know can't be right - is there a way to do this in the actual JSP program itself - like set the classpath just for that webpage?

Here's a good basic tutorial that helped me when I was getting started with tags:
http://www.theserverside.com/resources/article.jsp?l=JSP-XML3

Javabean class not found by jsp page

I have created one bean which has setFunctionId(String) and getFunctionId() methods. I put the class files at /weblogic/myserver/serverclasses directory. While I am accessing the .jsp page it is telling "Thu Aug 03 15:46:16 EDT 2000:<E> <ServletContext-General> Servlet failed with Ex
          ception
          java.lang.NoSuchMethodError: myjsp.TestBean: method setFunctionId(Ljava/lang/Str
          ing;)V not found
          at jsp_servlet._testasfs._jspService(_testasfs.java:90)
          at weblogic.servlet.jsp.JspBase.service(Compiled Code)
          at weblogic.servlet.internal.ServletStubImpl.invokeServlet(Compiled Code
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled C
          ode)
          at weblogic.servlet.internal.ServletContextImpl.invokeServlet(Compiled C
          ode)
          at weblogic.servlet.internal.ServletContextManager.invokeServlet(Compile
          d Code)
          at weblogic.socket.MuxableSocketHTTP.invokeServlet(Compiled Code)
          at weblogic.socket.MuxableSocketHTTP.execute(Compiled Code)
          at weblogic.kernel.ExecuteThread.run(Compiled Code)"
          Would appreciate your help..


Thank you for your valuable feedback duffymo. Could
you explain a little what you mean by "Putting .class
files in the Tomcat examples directory is a really bad
idea in the long run". Also, could you direct me to
some source where I can find more information on
creating WAR files keeping in mind that I am a
beginner.
Thanks.But putting your web apps into WAR files, you can have quite a few different web apps running on the tomcat server as compared to if u place your files into the default webapp folder, u can only have 1 web app running.
For creating WAR file, the easiest way is to use an IDE like JBuilder.

How to include a jsp page in another jsp jsp page

hi,
i m trying to include a jsp page name "header.jsp" into one jsp page name"selectattribute.jsp" i m using these commands in "selectattribute.jsp"
<%@include file "header.jsp"%> bcz both these jsp page are C:\program files\tomcat 4.0\webapps\examples\jsp\Poject\
but the problem is that , i m invoking this jsp page "selectattribute.jsp" from a servlet reportcontroller.java using REQUEST DISPATCHER.
the servlet is in
C:\Program files\tomcat 4.0\webapps\examples\WEB-INF\classes\Project\
i want to know how to include some other jsp page in a jsp page and how to invoke applet from jsp page when that particular jsp page is being invoked by servlet.
plz help
manish

use this for including in your selectattribute.jsp
<jsp:include page="header.jsp" flush="true"/>
I never tried calling an applet. I think you can write the code for calling the applet in a javabean method and call the method in the jsp

How can I access xml document from javascript whithin a JSP page

how can I access xml document from javascript whithin a JSP page?
I have a JSP that receives an XML document from a JavaBean, so I can access it within the entire JSP, but I need to access it from the javascript inside the JSP... and I have no idea how i can do this.
Thanks in advance!

The solution would only work on MS IE browsers, as other browsers do not support an XML DOM.
It can be done, but you would be stuck with using the Microsoft broswer. If that is acceptable, I have some example code, and a book recommendation.

How to format this table in jsp page?

I have a table in database and there are four data field in it.They are "id","name","email","registetime".
In javabean,I add all this data to a vector:" ResultSet rs;
while(rs.next()){
vec.add(rs.getString("id");
vec.add(rs.getString("name");
vec.add(rs.getString("email");
vec.add(rs.getString("registetime");} ";
I use a Iterator to read all the data to jsp page:"
               iter=vec.iterator();
               while(iter.hasNext()){
               int i=0;
               %>
               <table border="1" bordercolor="#FF6699" bgcolor="#CCCC99">
               <%
               if(i==0|i%8==0){
               out.println("<td><tr>");
               %>
               <%=iter.next()%>
               </td>
<%
               if(i%8==0)
               out.println("</tr></td>");
               i++;
               %></table>
I use a variable i for change range.I want to output a '\n' after output 4 data.But now the data in IE is this:
1
lyo
[email protected]
2003-6
2
Yashnoo
[email protected]
2003-7
It not that I want to get.I means I want to get data like this:
1 lyo [email protected] 2003-6
2 Yashnoo [email protected] 2003-7
How can I do? :(

Anyone has idea?But I change it to this:
<body>
<table border="1" bordercolor="#FF6699" bgcolor="#CCCC99">
<%
Iterator iter=null;
ResultSet rs=null;
Vector vec=new Vector();
vec=lyo.addData(rs,vec);
iter=vec.iterator();
try{
while(iter.hasNext()){
int i=0;
%>
<%
if(i%8==0){
out.print("<tr>");
out.print("<td>");
%>
<%=iter.next()%>
<%
out.print("</td>");
if(i%8==0){
out.print("</tr>");
i++;
%></table>
<%
}catch(Exception e){
out.println(e.toString());
%>
It can't help? Why?

How to use value returned from a bean in jsp page

Hi All,
I have a string array value being returned from a javabean to a jsp page. I want to be able to assign the value to a variable in the jsp page.
How do I do this?
Many thanks :)

thanks for your response.
I actually used something like this:
<% String loggedin = log.User(user,password);
out.println(loggedin);
%>i am not yet as much of an expert on beans as i would like to be, but i thought it is not really a bean if it has a getter method which takes arguments?

JSP on BEA Weblogic: random error when loading a jsp page that uses a Bean

Hi!
I wrote a simple jsp page that stores a String in a JavaBean, and then forwards to another jsp page to display that String. The jsp pages are deployed on a BEA Weblogic 6 Server, but I get a weird behaviour when loading the page into my browser. Usually I get an error message:
/Response.jsp(9): class 'query.jsp.QueryBean' could not be loaded
probably occurred due to an error in /Query.jsp line 9:
<jsp:useBean id = "queryBean" scope = "request" class = "query.jsp.QueryBean" />
But the funny thing is that after reloading the page a few times it eventually works. The bahaviour seems to be totally random - sometimes it works, sometimes it claims not finding the JavaBean class.
Anyone experienced something similar?
Thank you very much,
Charlie

Is QueryBean.class located under '<appname>/Web_inf/query/jsp/'?
If it is please try changing the package name to something else like com.myclass or something like that.

Error in Jsp page - undefined type

<html>
<%@ page contentType="text/html; charset=utf-8"
import="java.io.InputStream,
java.io.IOException,
javax.xml.parsers.SAXParser,
java.lang.reflect.*,
java.io.Writer.*, java.util.*,
javax.xml.parsers.SAXParserFactory"
session="false" %>
<%
* Copyright 2002,2004,2005 The Apache Software Foundation.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
%>
<%!
* Happiness tests for axis. These look at the classpath and warn if things
* are missing. Normally addng this much code in a JSP page is mad
* but here we want to validate JSP compilation too, and have a drop-in
* page for easy re-use
* @author Steve 'configuration problems' Loughran
* @author dims
* @author Brian Ewins
* test for a class existing
* @param classname
* @return class iff present
Class classExists(String classname) {
try {
return Class.forName(classname);
} catch (ClassNotFoundException e) {
return null;
* test for resource on the classpath
* @param resource
* @return true iff present
boolean resourceExists(String resource) {
boolean found;
InputStream instream=this.getClass().getResourceAsStream(resource);
found=instream!=null;
if(instream!=null) {
try {
instream.close();
} catch (IOException e) {
return found;
* probe for a class, print an error message is missing
* @param out stream to print stuff
* @param category text like "warning" or "error"
* @param classname class to look for
* @param jarFile where this class comes from
* @param errorText extra error text
* @param homePage where to d/l the library
* @return the number of missing classes
* @throws IOException
int probeClass(JspWriter out,
String category,
String classname,
String jarFile,
String description,
String errorText,
String homePage) throws IOException {
try {
Class clazz = classExists(classname);
if(clazz == null) {
String url="";
if(homePage!=null) {
url=getMessage("seeHomepage",homePage,homePage);
out.write(getMessage("couldNotFound",category,classname,jarFile,errorText,url));
return 1;
} else {
String location = getLocation(out, clazz);
if(location == null) {
out.write("<li>"+getMessage("foundClass00",description,classname)+"</li><br>");
else {
out.write("<li>"+getMessage("foundClass01",description,classname,location)+"</li><br>");
return 0;
} catch(NoClassDefFoundError ncdfe) {
String url="";
if(homePage!=null) {
url=getMessage("seeHomepage",homePage,homePage);
out.write(getMessage("couldNotFoundDep",category, classname, errorText, url));
out.write(getMessage("theRootCause",ncdfe.getMessage(), classname));
return 1;
* get the location of a class
* @param out
* @param clazz
* @return the jar file or path where a class was found
String getLocation(JspWriter out,
Class clazz) {
try {
java.net.URL url = clazz.getProtectionDomain().getCodeSource().getLocation();
String location = url.toString();
if(location.startsWith("jar")) {
url = ((java.net.JarURLConnection)url.openConnection()).getJarFileURL();
location = url.toString();
if(location.startsWith("file")) {
java.io.File file = new java.io.File(url.getFile());
return file.getAbsolutePath();
} else {
return url.toString();
} catch (Throwable t){
return getMessage("classFoundError");
* a class we need if a class is missing
* @param out stream to print stuff
* @param classname class to look for
* @param jarFile where this class comes from
* @param errorText extra error text
* @param homePage where to d/l the library
* @throws IOException when needed
* @return the number of missing libraries (0 or 1)
int needClass(JspWriter out,
String classname,
String jarFile,
String description,
String errorText,
String homePage) throws IOException {
return probeClass(out,
"<b>"+getMessage("error")+"</b>",
classname,
jarFile,
description,
errorText,
homePage);
* print warning message if a class is missing
* @param out stream to print stuff
* @param classname class to look for
* @param jarFile where this class comes from
* @param errorText extra error text
* @param homePage where to d/l the library
* @throws IOException when needed
* @return the number of missing libraries (0 or 1)
int wantClass(JspWriter out,
String classname,
String jarFile,
String description,
String errorText,
String homePage) throws IOException {
return probeClass(out,
"<b>"+getMessage("warning")+"</b>",
classname,
jarFile,
description,
errorText,
homePage);
* get servlet version string
public String getServletVersion() {
ServletContext context=getServletConfig().getServletContext();
int major = context.getMajorVersion();
int minor = context.getMinorVersion();
return Integer.toString(major) + '.' + Integer.toString(minor);
* what parser are we using.
* @return the classname of the parser
private String getParserName() {
SAXParser saxParser = getSAXParser();
if (saxParser == null) {
return getMessage("couldNotCreateParser");
// check to what is in the classname
String saxParserName = saxParser.getClass().getName();
return saxParserName;
* Create a JAXP SAXParser
* @return parser or null for trouble
private SAXParser getSAXParser() {
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
if (saxParserFactory == null) {
return null;
SAXParser saxParser = null;
try {
saxParser = saxParserFactory.newSAXParser();
} catch (Exception e) {
return saxParser;
* get the location of the parser
* @return path or null for trouble in tracking it down
private String getParserLocation(JspWriter out) {
SAXParser saxParser = getSAXParser();
if (saxParser == null) {
return null;
String location = getLocation(out,saxParser.getClass());
return location;
* Check if class implements specified interface.
* @param Class clazz
* @param String interface name
* @return boolean
private boolean implementsInterface(Class clazz, String interfaceName) {
if (clazz == null) {
return false;
Class[] interfaces = clazz.getInterfaces();
if (interfaces.length != 0) {
for (int i = 0; i < interfaces.length; i++) {
if (interfaces.getName().equals(interfaceName)) {
return true;
return false;
%>
<%@ include file="i18nLib.jsp" %>
<%
// initialize a private HttpServletRequest
setRequest(request);
// set a resouce base
setResouceBase("i18n");
%>
<head>
<title><%= getMessage("pageTitle") %></title>
</head>
<body bgcolor='#ffffff'>
<%
out.print("<h1>"+ getMessage("pageTitle") +"</h1>");
out.print("<h2>"+ getMessage("pageRole") +"</h2><p/>");
%>
<%= getLocaleChoice() %>
<%
out.print("<h3>"+ getMessage("neededComponents") +"</h3>");
%>
<UL>
<%
int needed=0,wanted=0;
* the essentials, without these Axis is not going to work
// need to check if the available version of SAAJ API meets requirements
String className = "javax.xml.soap.SOAPPart";
String interfaceName = "org.w3c.dom.Document";
Class clazz = classExists(className);
if (clazz == null || implementsInterface(clazz, interfaceName)) {
needed = needClass(out, "javax.xml.soap.SOAPMessage",
"saaj.jar",
"SAAJ API",
getMessage("criticalErrorMessage"),
"http://ws.apache.org/axis/");
} else {
String location = getLocation(out, clazz);
out.print(getMessage("invalidSAAJ",location));
out.print(getMessage("criticalErrorMessage"));
out.print(getMessage("seeHomepage","http://ws.apache.org/axis/java/install.html",getMessage("axisInstallation")));
out.print("<br>");
needed+=needClass(out, "javax.xml.rpc.Service",
"jaxrpc.jar",
"JAX-RPC API",
getMessage("criticalErrorMessage"),
"http://ws.apache.org/axis/");
needed+=needClass(out, "org.apache.axis.transport.http.AxisServlet",
"axis.jar",
"Apache-Axis",
getMessage("criticalErrorMessage"),
"http://ws.apache.org/axis/");
needed+=needClass(out, "org.apache.commons.discovery.Resource",
"commons-discovery.jar",
"Jakarta-Commons Discovery",
getMessage("criticalErrorMessage"),
"http://jakarta.apache.org/commons/discovery/");
needed+=needClass(out, "org.apache.commons.logging.Log",
"commons-logging.jar",
"Jakarta-Commons Logging",
getMessage("criticalErrorMessage"),
"http://jakarta.apache.org/commons/logging/");
needed+=needClass(out, "org.apache.log4j.Layout",
"log4j-1.2.8.jar",
"Log4j",
getMessage("uncertainErrorMessage"),
"http://jakarta.apache.org/log4j");
//should we search for a javax.wsdl file here, to hint that it needs
//to go into an approved directory? because we dont seem to need to do that.
needed+=needClass(out, "com.ibm.wsdl.factory.WSDLFactoryImpl",
"wsdl4j.jar",
"IBM's WSDL4Java",
getMessage("criticalErrorMessage"),
null);
needed+=needClass(out, "javax.xml.parsers.SAXParserFactory",
"xerces.jar",
"JAXP implementation",
getMessage("criticalErrorMessage"),
"http://xml.apache.org/xerces-j/");
needed+=needClass(out,"javax.activation.DataHandler",
"activation.jar",
"Activation API",
getMessage("criticalErrorMessage"),
"http://java.sun.com/products/javabeans/glasgow/jaf.html");
%>
</UL>
<%
out.print("<h3>"+ getMessage("optionalComponents") +"</h3>");
%>
<UL>
<%
* now the stuff we can live without
wanted+=wantClass(out,"javax.mail.internet.MimeMessage",
"mail.jar",
"Mail API",
getMessage("attachmentsError"),
"http://java.sun.com/products/javamail/");
wanted+=wantClass(out,"org.apache.xml.security.Init",
"xmlsec.jar",
"XML Security API",
getMessage("xmlSecurityError"),
"http://xml.apache.org/security/");
wanted += wantClass(out, "javax.net.ssl.SSLSocketFactory",
"jsse.jar or java1.4+ runtime",
"Java Secure Socket Extension",
getMessage("httpsError"),
"http://java.sun.com/products/jsse/");
* resources on the classpath path
/* add more libraries here */
%>
</UL>
<%
out.write("<h3>");
//is everythng we need here
if(needed==0) {
//yes, be happy
out.write(getMessage("happyResult00"));
} else {
//no, be very unhappy
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
out.write(getMessage("unhappyResult00",Integer.toString(needed)));
//now look at wanted stuff
if(wanted>0) {
out.write(getMessage("unhappyResult01",Integer.toString(wanted)));
} else {
out.write(getMessage("happyResult01"));
out.write("</h3>");
%>
<UL>
<%
//hint if anything is missing
if(needed>0 || wanted>0 ) {
out.write(getMessage("hintString"));
out.write(getMessage("noteString"));
%>
</UL>
<h2><%= getMessage("apsExamining") %></h2>
<UL>
<%
String servletVersion=getServletVersion();
String xmlParser=getParserName();
String xmlParserLocation = getParserLocation(out);
%>
<table border="1" cellpadding="10">
<tr><td>Servlet version</td><td><%= servletVersion %></td></tr>
<tr><td>XML Parser</td><td><%= xmlParser %></td></tr>
<tr><td>XML ParserLocation</td><td><%= xmlParserLocation %></td></tr>
</table>
</UL>
<% if(xmlParser.indexOf("crimson")>=0) { %>
<p>
<%= getMessage("recommendedParser") %>
</p>
<% } %>
<h2><%= getMessage("sysExamining") %></h2>
<UL>
<%
* Dump the system properties
java.util.Enumeration e=null;
try {
e= System.getProperties().propertyNames();
} catch (SecurityException se) {
if(e!=null) {
out.write("<pre>");
for (;e.hasMoreElements();) {
String key = (String) e.nextElement();
out.write(key + "=" + System.getProperty(key)+"\n");
out.write("</pre><p>");
} else {
out.write(getMessage("sysPropError"));
%>
</UL>
<hr>
<%= getMessage("apsPlatform") %>:
<%= getServletConfig().getServletContext().getServerInfo() %>
</body>
</html>
in the above jsp code i am getting errors such as "1.getMessage(String) is undefined for the type"
"2. setRequest(HttpServletRequest) is undefined for the type"
"3. getLocaleChoice() is undefined for the type"
whats wrong with the code??

I would also like to mention that you posted the original message... then barely an hour later made a comment that it was still unanswered.
In my time zone, you posted at 3:32 AM and then commented at 4:35 AM. I don't know about many people here, but I am fast asleep during that time.
So please understand we are here to help you, not be your servants to fix your problems.

Problem in getting an object in JSP page.

Hi experts,
I am forming a javabean object in the controller(servlet) and passing the object to a JSP page by setting that object as an attribute. But in that jsp page, when i compile, its not able to locate the class. At the beginning itself while typecasting the attribute as that bean object, i get an error. All the servlet, bean files are in the default package only.
This is how i used..
<%
String m = (String) request.getAttribute("mode");
//My bean object below.
adjuster_bean res=(adjuster_bean)request.getAttribute("data");
%>
And i am using like, calling the bean object's get method to set values of the text boxes in the JSP page. I need help please....

Vigsen wrote:
Hi experts,
I am forming a javabean object in the controller(servlet) and passing the object to a JSP page by setting that object as an attribute. But in that jsp page, when i compile, its not able to locate the class. At the beginning itself while typecasting the attribute as that bean object, i get an error. All the servlet, bean files are in the default package only.
This is how i used..
<%
String m = (String) request.getAttribute("mode");
//My bean object below.
adjuster_bean res=(adjuster_bean)request.getAttribute("data");
%>
And i am using like, calling the bean object's get method to set values of the text boxes in the JSP page. I need help please....Are you importing the bean class in your jsp? Something like this...
<%@ page import="java.util.*, yourpackage.YourBeanClass" %> Secondly, I see standards not followed in your code...
a) Firstly, as someone else pointed out in this same post. Avoid as much as possible using java scriplets in JSPs. Instead try use JSTL and EL expressions.
b) A java class name should always start with capital letter for every word in the class name and with no underscores. Your bean class name (adjuster_bean) should be changed to something like AdjusterBean
If you want to become a good Java programmer then standards are essential. But, again, it is totally up to you to follow.

Using JavaBean with JSP...will not work no matter what

Hi guys. Sorry that this is such a common, newb question, but I don't know where else to turn.
I'm new to web application development, Tomcat, and JSP. I'm trying to use a simple JavaBean in a JSP to store some user information. The JSP is located in $CATALINA_HOME\webapps\art , and the UserBean I'm trying to use is in $CATALINA_HOME\webapps\art\WEB-INF\classes . I've tried adding a context in the Tomcat server.xml file, but nothing seems to work, even putting the .class file into the \art directory along with the JSP. The error I get is the following:
org.apache.jasper.JasperException: Unable to compile class for JSP
An error occurred at line: 1 in the jsp file: /welcome.jsp
Generated servlet error:
[javac] Compiling 1 source file
C:\Program Files\Apache Group\Tomcat 4.1\work\Standalone\localhost\art\welcome_jsp.java:43: cannot resolve symbol
symbol : class UserBean
location: class org.apache.jsp.welcome_jsp
UserBean user = null;
^
The source code is:
welcome.jsp
<%@ page import="java.sql.*" %>
<jsp:useBean id="user" class="UserBean" scope="session"/>
<html>
<head>
<title>Art Webapp Test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<h1>Art Site</h1><br><br>
<h3>Welcome Page</h3><br><br>
<%
     user.setUsername("joe");
user.setTitle("admin");
%>
</body>
</html>
UserBean:
public class UserBean {
private String username = null;
private String title = null;
public UserBean()
     this.username = null;
     this.title = null;
public String getUsername()
     return this.username;
public String getTitle()
     return this.title;
public void setUsername(String inName)
     this.username = inName;
public void setTitle(String inTitle)
     this.title = inTitle;
}//UserBean
Thanks for any and all help anyone could give me about this. It seems such a simple thing, to get a JavaBean working in a JSP...and it's very frustrating to have it NOT work when it seems I've done everything possible to get it to.

Ok, I figured out what the problem was. My Bean was not a part of any specific package. It was never made clear to me that Beans are required to be a part of some package...I had no idea (though they always put them in packages in the tutorials, you think I would have picked up on it!).
So I just added the following line to the Bean:
package com.art;
Then compiled it and copied the .class file to CATALINA_HOME\webapps\art\WEB-INF\classes\com\art
Ta-da
Thanks for the help and sorry for taking up space on this board.
-Matt

No. of javabeans in jsp pages

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