Forwarding the array of object to servlet class
Hi
i am new to this j2ee.So please cooperate with me.
i am having an array of objects in a jsp page.
Each object represent a option which could be seelected through radio button.
Now i want to send one selected object,corresponding to selected radio button to my servlet ManageUser.
how can i do that.can any one help me please.
i have been trying like this but i guess it is not correct .
<%--
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="abc.javabean.EmpJavaBean"%>
<!--importing pages(classes) to implement request response -->
<%@page import="javax.servlet.ServletException"%>
<%@page import="javax.servlet.http.HttpServlet"%>
<%@page import="javax.servlet.http.*"%>
<%@page import="javax.servlet.RequestDispatcher"%>
<%@page import="java.util.*"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
<script type="text/javascript">
//function for selecting the radio
function validateRadio(fetchedArrayObject)
alert("hi");
var thisone=-1;
for(i=0;i<document.searchedEmpForm.radioGroup.length;i++)
if(searchedEmpForm.radioGroup.checked==true)
thisone=i;
alert(thisone);
var name=fetchedArrayObject[i].getEmpName();
alert(name);
session.setAttribute("fetchedArrayObject[i]",fetchedArrayObject[i]);
if(thisone==-1)
alert("you must select a radio Button");
return false;
return true;
</script>
</head>
<body bgcolor="#8db6cd">
<!--retreaving the array values from the servlet -->
<%
//int a;
EmpJavaBean fetchedArrayObject[]=new EmpJavaBean[4];
fetchedArrayObject=(EmpJavaBean[])request.getAttribute("substituteArray");
//a=fetchedArrayObject[0].getEmpNumber();
%>
<h3>ur new no is <%=fetchedArrayObject[0].getEmpNumber()%></h3><br>
<form name="searchedEmpForm" action="/Precize/ManageUser" onsubmit="return validateRadio(fetchedArrayObject)">
<br></br>
<h2 align="center">Your Searched Result Is Here</h2>
<br></br>
<table border="1" align="center">
<thead>
<tr>
<th> </th>
<th> <input type="button" value="Emp#" name="searchedPageEmpNumb"> </th>
<th> <input type="button" value="Name" name="searchedPageEmpName"> </th>
<th> <input type="button" value="Priv" name="searchedPageEmpPriv"> </th>
<th> <input type="button" value="Role" name="searchedPageEmpRole"> </th>
<th> <input type="button" value="Start Date" name="searchedPageEmpStartDate"> </th>
<th> <input type="button" value="End Date" name="searchedPageEmpEndDate"> </th>
</tr>
</thead>
<tbody>
<tr>
<td><input type="radio" name="radioGroup" value="r11" ></td>
<td><%=fetchedArrayObject[0].getEmpNumber()%></td>
<td><%=fetchedArrayObject[0].getEmpName()%></td>
<td><%=fetchedArrayObject[0].getEmpPrivilege() %></td>
<td><%=fetchedArrayObject[0].getEmpRole()%></td>
<td><%=fetchedArrayObject[0].getEmpStartdate()%></td>
<td><%=fetchedArrayObject[0].getEmpEndDate() %></td>
</tr>
</tbody>
</table>
<br><center><input type="submit" value="Update" name="updateButton" ></center>
<h3 align="center">Select the Employee To be Updated/deleted</h3>
</form>
</body>
</html>
please suggest me the answer.
regards
thanx
I think you need to learn the difference between "java" and "javascript"
calling session.setAttribute from a javascript function will not have the effect that you desire.
If you give all radio buttons the same "name", then request.getParameter("radioGroup") should tell you the value of the selected one.
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Lets suppose I have an interface, a string method name, and an array of Objects indicating the parameters which should be passed to the method.
What Im trying to work out is a way to quickly determine which method should be invoked.
I can see that Class has getDeclaredMethod(String, Class[]), but that wont help me as I dont know the formal class types (the method may take X, but I might get passed Y which extends X in the array of objects).
Does anyone know of a quick way I can determine this?
All I can think of at the moment is going thru each method of the class one by one, and seeing if the arg is assignable, then, after getting all my matched methods, determining if there are any more 'specific' matches.
Any ideas?
Much appreciated,
Daveyou might want to take a look at the dynamic proxy apiCheers for the suggestion, but Im actually already using the dynamic proxy API.
What I have is a MockObjectValidator which allows mock objects to be configuered with expected calls, exceptions to throw etc etc.
I thought developers on my project would get tired using an interface like this:
myValidator.setExpectedCall("someMethod", new Class[] { typeA, typeB }, new Object[] { valueA, valueB} );
I.e, I wanted to cut out having to pass the class array, so they could just use:
myValidator.setExpectedCall("someMethod", new Object[] { valueA, valueB} );
The problem there is that I then need to pick the best Method from the class given the object arguments.
When the mock object is in use, its no problem as the InvocationHandler interface provides the Method. The problem I have is selecting what method a user is talking about from an array of Objects.
Ive written a simple one now, it just does primitive type class -> wrapper substitution, and then finds ** A ** match. If there is more than one match (ie, all params are assignable to a class' method params), I dont let that method be used.
Shortly I'll update it to actually make the correct selection in those cases.
cheers
Dave -
Hi,
I'm having trouble creating an array of objects to store data I'm reading in from a text file.
I have created a class called mssg, and as I read each line of the textfile in, I've created a method called setMsg that I'm using to populate the mssg object I've created.
This works fine when I use this method on a single instance of a mssg object, but when I try to use the same code on a mssg object that's part of an array, I get an exception (and one that doesn't have any friendly error text)
mssg ms = new mssg(); //this works as expected
mssg msgs[] = new mssg [msgCounter]; //I believe the exception relates to how I'm declaring the array of objects here, but the exception doesn't occur until I try to assign data to an element of the arrayThe lines below are where the problem becomes apparent. The first object 'ms' gets assigned its values as I'd expect, however, the line below that tries to assign values to a mssg object in the msgs array, and I get an exception immediately.
ms.setMsg(currMsg,mDt,mTm,mDir,mData);
msgs[currMsg].setMsg(currMsg,mDt,mTm,mDir,mData);Can anyone tell me what I'm doing wrong in terms of declaring/assigning values to an array of objects?It's the following error: java.lang.NullPointerException
Full error text if I take my code out of a try/catch loop is:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at FIXparserUI.jMenuLoadActionPerformed(FIXparserUI.java:301)
at FIXparserUI.access$100(FIXparserUI.java:20)
at FIXparserUI$3.actionPerformed(FIXparserUI.java:129)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.AbstractButton.doClick(AbstractButton.java:357)
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1170)
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1211)
at java.awt.Component.processMouseEvent(Component.java:6038)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3260)
at java.awt.Component.processEvent(Component.java:5803)
at java.awt.Container.processEvent(Container.java:2058)
at java.awt.Component.dispatchEventImpl(Component.java:4410)
at java.awt.Container.dispatchEventImpl(Container.java:2116)
at java.awt.Component.dispatchEvent(Component.java:4240)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4322)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3986)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3916)
at java.awt.Container.dispatchEventImpl(Container.java:2102)
at java.awt.Window.dispatchEventImpl(Window.java:2429)
at java.awt.Component.dispatchEvent(Component.java:4240)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)at the point that the following line of code is run:
msgs[currMsg].setMsg(currMsg,mDt,mTm,mDir,mData);msgCounter is used to count the number of lines in the file (about 2300)
I had hoped that what I was doing with this line:
mssg msgs[] = new mssg [msgCounter];was create 2300 empty mssg records, ready to be populated from each line of data, however I have the feeling you're going to tell me I'm wrong. -
Formatted .data file, reading in and creating an array of objects from data
Hi there, I have written a text file with the following format;
List of random personal data: length 100
1 : Atg : Age 27 : Income 70000
2 : Dho : Age 57 : Income 110000
3 : Lid : Age 40 : Income 460000
4 : Wgeecnce : Age 43 : Income 370000
and so on.
These three pieces of data, Name,Age and Income were all generated randomly to be stored in an array of objects of class Person.
Now what I must do is , read in this very file and re-create the array of objects that they were initially written from.
I'm totally lost on how to go about doing this, I have only been learning java for the last month so anyone that can lend me a hand, that would be superb!
Cheers!Looking at you other thread, you are able to create the code needed - so what's the problem?
Here's an (not the only) approach:
Create an array of the necessary length to hold the 3 variables, or, if you don't know the length of the file, create a class to contain the data. Then create an ArrayList to hold an instance of the class..
Use the Scanner class to read and parse the file contents into the appropriate variables.
Add each variable to either the array, or to an instance of the class and add that instance to the arraylist. -
Accessing data in an array of objects..
I've created the classes
public class Box
int width;
int height;
int depth;
public Box(int a, int b, int c)
width = a;
height = b;
depth = c;
public void getWidth()
System.out.println(width);
public void getHeight()
System.out.println(height);
public void getDepth()
System.out.println(depth);
}and this collection of boxes...
public class Collecton
int count = 0;
Box[] BoxCollection;
public Collection
BoxCollection = new Box[50]
public recbox(int a, int b, int c)
BoxCollection[count] = new Box(a, b, c)
count++
public printBoxes()
System.out.println("Box Number = " + count);
System.out.print("Box Width: ");
BoxCollection[count].getWidth();
etc...
}Now, I call this in the main code so that after each box is created, the specs of the box is printed back out onto the screen. The calling procedure works
However, only the Box Number part seems to print... the width, height and depth all don't work.
Am I accessing the data stored in the array of objects incorrectly?
Please advise.
Thanksa b and c come from user inputs via an input/output lib... and you are sure this user input works? Perhaps you're searching in the wrong place: Do a System.out.println(a + ", " + b + ", " + c) just after getting that user input (from console?) and check the values.
Patrick -
Plz help!! array of object (for search)
i've got few questions of array of object
1-how to search for a price that is greater than 300 in the array of object
and how to list all of them?
2- how to search for the smallest price in the array of object, and how to list?
can anyone provde a java code for me:P?
but plz don't too complex
coz i'm a learner of javaT_T_< i still can't understand, and dunno how to change into the code that i needand you guyz help me change it?
/*wirte the driver program which will define and create an array of
objects instantiated from the class WaterBill
Create Accessor and Mutator methods to get/set data from the class.
write code within the driver method to perfrom the following:
a) The final total of funds
b) To search for accounts greater than $300 in the array of objects,
and list all the customer details
c)To search for the lowest bill in the array of objects, and list
those customer dtails
Class definitions and Objects using price
import java.text.*;
import javax.swing.JOptionPane;
public class Pre_pb3
public static void main(String []args)
int TTc=0;
int accNum[]=new int[20];
String name[]=new String[20], output, stans, display; //stAccNum, stUsage, stTTc;
double usage[]=new double[20];
double TTa=0.0;
double price[]=new double[20];
char ans;
double acctG,lowest;
int i=0;
waterBill MYwaterBill = new waterBill();
ans='Y';
while (!(ans=='N'))
name=inputName();
accNum[i]=inputAccNum();
usage[i]=inputUsage();
price[i]=calculateAmountOwing(usage[i]);
TTa=MYwaterBill.TTaPrice(price[i]);
output=MYwaterBill.outputInfo(name[i], accNum[i], usage[i], price[i]);
waterBill MYwaterBill2= new waterBill(name[i], accNum[i],usage[i], price[i]);
stans=JOptionPane.showInputDialog("Do you wanna continue?, (Y)es, (N)o");
stans = stans.substring(0, 1);
stans=stans.toUpperCase();
ans=stans.charAt(0);
TTc++;
MYwaterBill.outputoutput(TTc, TTa);
MYwaterBill.findGreat(); //b)
MYwaterBill.searchDetail(); //c)
System.exit(0);
public static String inputName()
String name;
name=JOptionPane.showInputDialog("Enter Name ");
return name;
public static int inputAccNum()
int accNum;
String stAccNum;
stAccNum=JOptionPane.showInputDialog("Enter Account Number");
accNum=Integer.parseInt(stAccNum);
return accNum;
public static double inputUsage()
double usage;
String stUsage;
stUsage=JOptionPane.showInputDialog("Enter Water Usage");
usage=Double.parseDouble(stUsage);
if (!(usage>=0 && usage<=99999999))
System.out.println("water useage is invalid");
System.exit(0);
return usage;
public static double calculateAmountOwing(double usage)
double price=0.0;
if (usage>=0)
if (usage<=10000)
price=(10000/10)*0.01;
else if (usage>10000)
price=((10000/10)*0.01)+(((usage-10000)/10)*0.02);
else
System.out.println("Error of usage");
return price;
class waterBill
private static int TTc=0 ,accNum=0;
private static String name, stAccNum, stUsage, stTTc;
private static String output=" ";
private static double usage=0.0;
private static double TTa=0.0;
private static double price=0.0;
private static String lowest;
public waterBill()
name=" ";
accNum=0;
usage=0.0;
price=0.0;
public waterBill(String n,int an, double us, double p)
setName(n);
setAccNum(an);
setUsage(us);
setPrice(p);
public void setName(String n)
name=n;
public void setAccNum(int an)
accNum=an;
public void setUsage(double us)
usage=us;
public void setPrice(double p)
price=p;
public String getName()
return name;
public int getAccNum()
return accNum;
public double getUsage()
return usage;
public double getPrice()
return price;
public double TTaPrice(double price)
TTa=TTa + price;
return TTa;
public String outputInfo(String name, int accNum, double usage, double price )
String output=" ";
output: System.out.println( "Account Number: "+ accNum +
"\nWater Usage: " + usage +
"\nCost Owing: " price
"\nName: "+ name+"\n");
return output;
public void outputoutput(int TTc, double TTa)
display: System.out.println("Total customer: "+ TTc +
"\nTotal amount owing: " + TTa + "\n\n");
public void findGreat()//search the a/c that is greater than 300.
//dunno how to do, so i just leave it blank^^"
public String searchDetail()//search the smallest a/c
//same...dunno how to doT_T
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