Problem In ArrayList
Hai to every one,
i am having problem with Array list.
My Problem:
i want insert the resultset from database to ArrayList so i have created a ArrayList as below
ArrayList list = new ArrayList(20);
and i am inserting database records into arraylist following code
int i =0;
while (rs.next ())
list.add(i, rs.getString(1));
i++;
but i am getting following error at this line
list.add(i, rs.getString(1));
Error as
===========> SalesRep.getSalesPerson: select * from (select name, rownum as row_num from c_bpartner where ISSALESREP ='Y' AND ad_client_id=1000005 AND ad_org_id =1000007 ) where row_num between 1 AND 20 [11]
java.lang.NullPointerException
at org.compiere.pos.SalesRep.getSalesPerson(SalesRep.java:386)
at org.compiere.pos.SalesRep.init(SalesRep.java:95)
at org.compiere.pos.PosSubPanel.<init>(PosSubPanel.java:22)
at org.compiere.pos.SalesRep.<init>(SalesRep.java:45)
at org.compiere.pos.PosPanel.dynInit(PosPanel.java:211)
at org.compiere.pos.PosPanel.init(PosPanel.java:86)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:243)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:210)
at org.compiere.apps.AMenuStartItem.startForm(AMenuStartItem.java:293)
at org.compiere.apps.AMenuStartItem.run(AMenuStartItem.java:161)
can any one help me.. its very urgent.....
private int Low_Limit = 1 , Upper_Limit = 20;
ArrayList list = new ArrayList(20);
@Override
protected void init() {
// TODO Auto-generated method stub
getSalesPerson(Low_Limit,Upper_Limit);
System.out.print("After Get Opertions");
public void CreateButtons(int low, int up)
int COLUMNS = 4; // Min Columns
int ROWS = 5; // Min Rows
int noKeys = list.size();
System.out.println("No of Reps:"+ noKeys);
int rows = Math.max(((noKeys - 1) / COLUMNS) + 1, ROWS);
int cols = ((noKeys - 1) % COLUMNS) + 1;
log.fine("PosSubFunctionKeys.init - NoKeys=" + noKeys + " - Rows="
+ rows + ", Cols=" + cols);
setLayout(new BorderLayout(2,2));
setVisible(false);
setBorder(new TitledBorder(Msg.translate(
Env.getCtx(), "Sales Persons")));
CPanel content = new CPanel(new GridLayout(Math.max(ROWS, 5), Math.max(
COLUMNS, 4)));
for (int i = 0; i < noKeys; i++) {
String Saleperson = (String) list.get(i);
CButton button = new CButton(Saleperson);
content.add(button);
add(content,BorderLayout.WEST);
public void actionPerformed(ActionEvent e) {
String action = e.getActionCommand();
if (action == null || action.length() == 0)
return;
if (action != "Back")
System.out.println("Inside Sales Block"+action);
setSalesperson(action);
if (action.equals("Back")) {
p_posPanel.closeQuery(p_posPanel.s_SalesRep);
public void dispose() {
removeAll();
protected GridBagConstraints getGridBagConstraints() {
GridBagConstraints gbc = super.getGridBagConstraints();
gbc.gridx = 0;
gbc.gridy = 3; //GridBagConstraints.RELATIVE;
gbc.gridwidth = 1; // GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 0.1;
gbc.weighty = 0.5;
return gbc;
} // getGridBagConstraints
public void setSalesperson (String salesPerson)
System.out.print("inside set Sales Person method:"+salesPerson);
p_posPanel.f_salesRep.f_Sreplabel.setText(salesPerson);
public void getSalesPerson (int low,int upper)
int ad_client_id = 1000005;
int ad_org_id = 1000007,i=1;
String sql = " select * from " +
"(select name, rownum as row_num from c_bpartner where ISSALESREP ='Y' AND ad_client_id=1000005 " +
"AND ad_org_id =1000007 ) where row_num between 1 AND 20 ";
try
PreparedStatement pstmt = DB.prepareStatement (sql,null);
ResultSet rs = pstmt.executeQuery ();
while (rs.next ())
{list.add(i, rs.getString(1));
i++;}
catch (Exception e)
log.log(Level.SEVERE, sql, e);
this my program in which each time i will pass some parameter to access database value
this should be stored in ArrayList and i will access the value for creating button at runtime..
but i getting error as follows
===========> SalesRep.getSalesPerson: select * from (select name, rownum as row_num from c_bpartner where ISSALESREP ='Y' AND ad_client_id=1000005 AND ad_org_id =1000007 ) where row_num between 1 AND 20 [11]
java.lang.NullPointerException
at org.compiere.pos.SalesRep.getSalesPerson(SalesRep.java:386)
at org.compiere.pos.SalesRep.init(SalesRep.java:95)
at org.compiere.pos.PosSubPanel.<init>(PosSubPanel.java:22)
at org.compiere.pos.SalesRep.<init>(SalesRep.java:45)
at org.compiere.pos.PosPanel.dynInit(PosPanel.java:211)
at org.compiere.pos.PosPanel.init(PosPanel.java:86)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:243)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:210)
at org.compiere.apps.AMenuStartItem.startForm(AMenuStartItem.java:293)
at org.compiere.apps.AMenuStartItem.run(AMenuStartItem.java:161)
After Get Opertions===========> PosPanel.init: init [11]
java.lang.NullPointerException
at org.compiere.pos.SalesRep.CreateButtons(SalesRep.java:116)
at org.compiere.pos.SalesRep.init(SalesRep.java:101)
at org.compiere.pos.PosSubPanel.<init>(PosSubPanel.java:22)
at org.compiere.pos.SalesRep.<init>(SalesRep.java:45)
at org.compiere.pos.PosPanel.dynInit(PosPanel.java:211)
at org.compiere.pos.PosPanel.init(PosPanel.java:86)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:243)
at org.compiere.apps.form.FormFrame.openForm(FormFrame.java:210)
at org.compiere.apps.AMenuStartItem.startForm(AMenuStartItem.java:293)
at org.compiere.apps.AMenuStartItem.run(AMenuStartItem.java:161)
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jbtFirstActionPerformed(evt);
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jbtNext.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
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jbtPrevious.setText("Previous");
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jbtPreviousActionPerformed(evt);
jbtLast.setText("Last");
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jbtAdd.setText("Add");
jbtAdd.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jbtAddActionPerformed(evt);
jbtDelete.setText("Delete");
jbtModify.setText("Modify");
jbtModify.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jbtModifyActionPerformed(evt);
jbtSave.setText("Save");
jbtSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jbtSaveActionPerformed(evt);
jPanel2.setBorder(javax.swing.BorderFactory.createTitledBorder(javax.swing.BorderFactory.createEtchedBorder(), "Search by:"));
searchIDNumLbl.setText("Item Number:");
jbtSearch.setText("Search");
searchResults.setFont(new java.awt.Font("Tahoma", 1, 12));
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addContainerGap()
.addComponent(searchIDNumLbl)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(259, 259, 259)
.addComponent(searchResults, javax.swing.GroupLayout.PREFERRED_SIZE, 213, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jbtSearch, javax.swing.GroupLayout.PREFERRED_SIZE, 83, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(searchIDNumbField, javax.swing.GroupLayout.PREFERRED_SIZE, 143, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(searchIDNumLbl)
.addComponent(searchIDNumbField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(32, 32, 32)
.addComponent(searchResults, javax.swing.GroupLayout.PREFERRED_SIZE, 17, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createSequentialGroup()
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtSearch)))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
jbtExit.setText("Save and Exit");
jbtExit.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jbtExitActionPerformed(evt);
jbtExitwoSave.setText("Exit");
jbtExitwoSave.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jbtExitwoSaveActionPerformed(evt);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, 248, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 44, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(jbtExitwoSave, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jbtExit)))
.addGroup(layout.createSequentialGroup()
.addComponent(jbtFirst)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtNext)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtPrevious)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtLast))
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGap(12, 12, 12)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jbtAdd)
.addComponent(jbtDelete)
.addComponent(jbtModify)
.addComponent(jbtSave))))
.addContainerGap())
layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {jbtFirst, jbtLast, jbtNext, jbtPrevious});
layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {jbtAdd, jbtDelete, jbtModify, jbtSave});
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(21, 21, 21)
.addComponent(jbtAdd)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtDelete)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtModify)
.addGap(39, 39, 39)
.addComponent(jbtSave))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jbtFirst)
.addComponent(jbtNext)
.addComponent(jbtPrevious)
.addComponent(jbtLast))
.addGap(15, 15, 15)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addComponent(jbtExit)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jbtExitwoSave)))
.addContainerGap())
pack();
}// </editor-fold>
private void jbtExitwoSaveActionPerformed(java.awt.event.ActionEvent evt) {
System.exit(0);
private void jbtSaveActionPerformed(java.awt.event.ActionEvent evt) {
String prodNameMod, colorMod;
double unitsInStockMod, unitPriceMod;
int idNumMod;
idNumMod = Integer.parseInt(IDNumberField.getText());
prodNameMod = prodNameField.getText();
unitsInStockMod = Double.parseDouble(unitsInStockField.getText());
unitPriceMod = Double.parseDouble(unitPriceField.getText());
colorMod = colorField.getText();
if(currentProductIndex == inventory.length) {
inList.add(new InventoryPlusColor(idNumMod, prodNameMod,
unitsInStockMod, unitPriceMod, colorMod));
InventoryPlusColor[] inventory = (InventoryPlusColor[]) inList.toArray
(new InventoryPlusColor[inList.size()]);
} else {
inventory[currentProductIndex].setIDNumber(idNumMod);
inventory[currentProductIndex].setProdName(prodNameMod);
inventory[currentProductIndex].setUnitsInStock(unitsInStockMod);
inventory[currentProductIndex].setUnitPrice(unitPriceMod);
inventory[currentProductIndex].setColor(colorMod);
displayProduct(inventory[currentProductIndex]);
private static void writeInventory(InventoryPlusColor i,
DataOutputStream out) {
try {
out.writeInt(i.getIDNumber());
out.writeUTF(i.getProdName());
out.writeDouble(i.getUnitsInStock());
out.writeDouble(i.getUnitPrice());
out.writeUTF(i.getColor());
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "I/O Exception writing data",
"", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} //end writeInventory()
private static DataOutputStream openOutputStream(String name) {
DataOutputStream out = null;
try {
File file = new File(name);
out =
new DataOutputStream(
new BufferedOutputStream(
new FileOutputStream(file)));
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "I/O Error", "", JOptionPane.ERROR_MESSAGE);
System.exit(0);
return out;
} // end openOutputStream()
private static void closeFile(DataOutputStream out) {
try {
out.close();
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "I/O Exception closing file",
"", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} // end closeFile()
private static DataInputStream getStream(String name) {
DataInputStream in = null;
try {
File file = new File(name);
in = new DataInputStream(
new BufferedInputStream(
new FileInputStream(file)));
} catch (FileNotFoundException e) {
JOptionPane.showMessageDialog(null, "The file doesn't exist",
"", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "I/O Error creating file",
"", JOptionPane.ERROR_MESSAGE);
System.exit(0);
return in;
private static void closeInputFile(DataInputStream in) {
try {
in.close();
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "I/O Exception closing file",
"", JOptionPane.ERROR_MESSAGE);
System.exit(0);
} // end closeInputFile()
private double entireInventory() {
// a temporary double variable that the method will return ...
// after each product's inventory is added to it
double entireInventory = 0;
// loop to control number of products
for (int index = 0; index < inventory.length; index++) {
// add each inventory to the entire inventory
entireInventory += inventory[index].setInventoryValue();
} // end loop to control number of products
return entireInventory;
} // end method entireInventory
private void jbtLastActionPerformed(java.awt.event.ActionEvent evt) {
currentProductIndex = inventory.length-1; // move to the last product
// display the information for the last product
displayProduct(inventory[currentProductIndex]);
private void jbtPreviousActionPerformed(java.awt.event.ActionEvent evt) {
if (currentProductIndex != 0) // it's not the first product displayed
currentProductIndex -- ; // move to the previous product (decrement the current index)
} else // the first product is displayed
currentProductIndex = inventory.length-1; // move to the last product
// after the current product index is set, display the information for that product
displayProduct(inventory[currentProductIndex]);
private void jbtNextActionPerformed(java.awt.event.ActionEvent evt) {
if (currentProductIndex != inventory.length-1) // it's not the last product displayed
currentProductIndex ++ ; // move to the next product (increment the current index)
} else // the last product is displayed
currentProductIndex = 0; // move to the first product
// after the current product index is set, display the information for that product
displayProduct(inventory[currentProductIndex]);
private void jbtFirstActionPerformed(java.awt.event.ActionEvent evt) {
currentProductIndex = 0;
// display the information for the first product
displayProduct(inventory[currentProductIndex]);
private void colorFieldActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
private void jbtModifyActionPerformed(java.awt.event.ActionEvent evt) {
prodNameField.setEditable(true);
prodNameField.setFocusable(true);
unitsInStockField.setEditable(true);
unitPriceField.setEditable(true);
private void jbtAddActionPerformed(java.awt.event.ActionEvent evt) {
IDNumberField.setText("");
IDNumberField.setEditable(true);
prodNameField.setText("");
prodNameField.setEditable(true);
colorField.setText("");
colorField.setEditable(true);
unitsInStockField.setText("");
unitsInStockField.setEditable(true);
unitPriceField.setText("");
unitPriceField.setEditable(true);
restockingFeeField.setText("");
invenValueField.setText("");
currentProductIndex = inventory.length;
private void jbtExitActionPerformed(java.awt.event.ActionEvent evt) {
DataOutputStream out = openOutputStream("inventory.dat");
for (InventoryPlusColor i : inventory)
writeInventory(i, out);
closeFile(out);
System.exit(0);
private static InventoryPlusColor readProduct(DataInputStream in) {
int idNum = 0;
String prodName = "";
double inStock = 0.0;
double pricBalusC -- The line that gives me my NullPointerException is when I call the "DisplayProduct()" method. Its a dumb question, but with NetBeans how do I find out which reference could be null? I'm not very familiar with how NetBeans works with finding out how to debug. Any help you can give me would be greatly appreciated.The IDE is com-plete-ly irrelevant. It's all about the source code.
Do you understand anyway when and why a NullPointerException is been thrown? It is a subclass of RuntimeException and those kind of exceptions are very trival and generally indicate an design/logic/thinking fault in your code.
SomeObject someObject = null; // The someObject reference is null.
someObject.doSomething(); // Invoking a reference which is null would throw NPE. -
Problem getting arraylist values from request
Hi All,
I am trying to display the results of a search request.
In the jsp page when I add a scriplet and display the code I get the values else it returns empty as true.Any help is appreciated.
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<%@ include file="/includes/header.jsp"%>
<title>Research Results</title>
</head>
<body>
<div class="ui-widget ui-widget-content">
<%
ArrayList<Research> research = (ArrayList<Research>) request.getAttribute("ResearchResults");
Iterator iterator = research.iterator();
while(iterator.hasNext()){
Research r = (Research) iterator.next();
out.println("Result Here"+r.getRequesterID());
out.println("Result Here"+r.getStatus());
%>
<form>
<c:choose>
<c:when test='${not empty param.ResearchResults}'>
<table cellspacing="0" cellpadding="0" id="research" class="sortable">
<h2>RESEARCH REQUESTS</h2>
<tr>
<th><a href="#">RESEARCH ID</a></th>
<th><a href="#">REQUESTOR NAME</a></th>
<th><a href="#">DUE DATE</a></th>
<th><a href="#">REQUEST DATE</a></th>
<th><a href="#">CLIENT</a></th>
<th><a href="#">STATUS</a></th>
<th><a href="#">PRIORITY</a></th>
</tr>
<c:forEach var="row" items="${param.ResearchResults}">
<tr title="">
<td id="researchID">${row.RESEARCH_ID}</td>
<td>${row.REQUESTER_FNAME} ${row.REQUESTER_LNAME}</td>
<td><fmt:formatDate pattern="MM/dd/yyyy" value="${row.DUE_DATE}"/></td>
<td><fmt:formatDate pattern="MM/dd/yyyy" value="${row.CREATED_DATE}"/></td>
<td>${row.CLIENT}</td>
<td>
<c:choose>
<c:when test="${row.STATUS=='10'}">New Request</c:when>
<c:when test="${row.STATUS=='20'}">In Progress</c:when>
<c:when test="${row.STATUS=='30'}">Completed</c:when>
</c:choose>
</td>
<td>
<c:choose>
<c:when test="${row.PRIORITY=='3'}">Medium</c:when>
<c:when test="${row.PRIORITY=='2'}">High</c:when>
<c:when test="${row.PRIORITY=='1'}">Urgent</c:when>
</c:choose>
</td>
</tr>
</c:forEach>
</table>
</c:when>
<c:otherwise>
<div class="ui-state-highlight ui-corner-all">
<p><b>No results Found. Please try again with a different search criteria!</b> </p>
</div>
</c:otherwise>
</c:choose>
</form>
<%@ include file="/includes/footer.jsp"%>
</div>
</body>
</html>What is ResearchResults?
Is it a request parameter or is it a request attribute?
Parameters and attributes are two different things.
Request parameters: the values submitted from the form. Always String.
Request attributes: objects stored into scope by your code.
They are also accessed slightly differently in EL
java syntax == EL syntax
request.getParameter("myparameter") == ${param.myparameter}
request.getAttribute("myAttribute") == ${requestScope.myAttribute}
You are referencing the attribute in your scriptlet code, but the parameter in your JSTL/EL code.
Which should it be?
cheers,
evnafets -
Problem getting arraylist from another class
I am trying to call information about an arraylist from another class. I am using this code to call the size of an arraylist:
import java.io.*;
public class Test
public static void main(String argv[]) throws IOException
Echo03 thing = new Echo03();
int y=thing.value();
System.out.println(y);
Echo03 thing2 = new Echo03();
int x=thing2.percent.size();
System.out.println(x);
}from another file which starts like this:
public class Echo03 extends DefaultHandler
static ArrayList<String> percent = new ArrayList<String>();
static ArrayList<String> text = new ArrayList<String>();
int a;
public int value(){
return percent.size();
public static void main(String argv[]) throws IOException
{The second file is based on an example piece of code from the Java website. I havent posted the whole thing, but if it is relevant then please ask.
Anyway when I run Echo03 by itself, the arraylist has a size of 2. But when I run it from the Test file, it says a size of 0. Is this because the data is not being transferred between the classes? Or is the Echo03 program not executing (and hence the arraylist is not filling up)?
How can I fix this? I have tried 2 ways of calling the data (As seen in my Test file). Neither work.I didnt post the full bit of the code for the second one. Here it is:
import java.io.*;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import java.util.ArrayList;
import java.awt.*;
import javax.swing.*;
public class Echo03 extends DefaultHandler
static ArrayList<String> percent = new ArrayList<String>();
static ArrayList<String> text = new ArrayList<String>();
int a;
public static void main(String argv[]) throws IOException
if (argv.length != 1) {
System.err.println("Usage: cmd filename");
System.exit(1);
// Use an instance of ourselves as the SAX event handler
DefaultHandler handler = new Echo03();
// Use the default (non-validating) parser
SAXParserFactory factory = SAXParserFactory.newInstance();
try {
// Set up output stream
out = new OutputStreamWriter(System.out, "UTF8");
// Parse the input
SAXParser saxParser = factory.newSAXParser();
saxParser.parse( new File(argv[0]), handler);
for (int b=0; b<percent.size();b++){
System.out.println(percent.get(b+1));
} catch (Throwable t) {
System.exit(0);
static private Writer out;
public void startElement(String namespaceURI,
String lName, // local name
String qName, // qualified name
Attributes attrs)
throws SAXException
if (attrs != null) {
StringBuffer sb = new StringBuffer (250);
for (int i = 0; i < attrs.getLength(); i++) {
nl();
emit(attrs.getValue(i));
sb.append (attrs.getValue(i));
String sf = sb.toString ();
percent.add(sf);
System.out.println(" String: "+sf); a++;
public void characters(char buf[], int offset, int len)
throws SAXException
emit(" ");
String s = new String(buf, offset, len);
if (!s.trim().equals("")) {text.add(s); emit(s);}
//===========================================================
// Utility Methods ...
//===========================================================
// Wrap I/O exceptions in SAX exceptions, to
// suit handler signature requirements
private void emit(String s)
throws SAXException
try {
out.write(s);
out.flush();
} catch (IOException e) {
throw new SAXException("I/O error", e);
// Start a new line
private void nl()
throws SAXException
String lineEnd = System.getProperty("line.separator");
try {
out.write(lineEnd);
} catch (IOException e) {
throw new SAXException("I/O error", e);
} -
So i have to make this project which require a lot of classes, and since this is my first time making a project that require numerous classes i am having a difficult time
so what i did was that i stored one arraylist that is in a train class in which i put all of my polygons points into, then i put the arraylist in my train class into another arraylist in a class called Object class.
how ever whenever i try and do
System.out.println(newobject.getobject().get(0).get(0));i keep getting the error message
C:\Documents and Settings\John\My Documents\project\project101.java:100: cannot find symbol
symbol : method get(int)
location: class java.lang.Object
System.out.println(newobject.getobject().get(0).get(0));ArrayList's get(int) returns an Object-type reference. And Objects don't have a get() method you could call. You need a cast or generics.
By the way, you might want to learn about object-orientation. -
Further problem with ArrayLists
Dear all,
I am having trouble with my Java assignment, where we have to create a library system. I have two ArrayLists:
- One to hold objects of type Borrower
- One to hold objects of type Book
These work fine, i can add and delete from them. However, i apparently need to create a third ArrayList where details of the borrowing is held i.e. where the details which borrower has which books.
Can anyone point me in the direction of how i can go about implementing this? Im completely stuck, and do not know where to begin!
Here is my code so far for the classes involved: The borrower and books are super classes, but i dont think i need to give the subclass details....any help is very much appreciated, thank you in advance!
Library class:
import java.util.*;
import java.util.Scanner;
import java.util.Iterator;
* @author Mr. Balls
public class Library {
private ArrayList bookList = new ArrayList();
private ArrayList borrowerList = new ArrayList();
private ArrayList loansList = new ArrayList();
int totalLoans = 0;
public Library(ArrayList bookList){
this.bookList = bookList;
public Library(){
public void addBook(){
String title, author;
int catNumber, noCopy;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the title of the book: ");
title = scan.nextLine();
System.out.println("Enter the name of the author: ");
author = scan.nextLine();
System.out.println("Enter the catalogue number: ");
catNumber = scan.nextInt();
System.out.println("Enter the number of copies: ");
noCopy = scan.nextInt();
//need to differentiate between standard and reference books here
bookList.add(new Book(title,author,catNumber,noCopy));
}//addBook
public void addBorrower(){
String name;
int libNumb, type;
Scanner scan = new Scanner(System.in);
System.out.println("Enter borrowers name: ");
name = scan.nextLine();
System.out.println("Enter library number: ");
libNumb = scan.nextInt();
System.out.println("Enter borrower type ");
System.out.println("1: Student ");
System.out.println("2: Lecturer ");
type = scan.nextInt();
if(type == 1){
borrowerList.add(new Student(name, libNumb));
else{
borrowerList.add(new Lecturer(name, libNumb));
public void printBooks(){//temp method to check everything works
int size;
size = bookList.size();
for (int i = 0;i < size;i++){
System.out.println(bookList.get(i));
size = borrowerList.size();
for (int i = 0;i < size;i++){
System.out.println(borrowerList.get(i));
public void deleteBook(){
String searchTitle;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the book title you wish to delete: ");
searchTitle = scan.nextLine();
ListIterator it = bookList.listIterator();
while(it.hasNext()){
Book book = (Book) it.next();
if(book.title.equals(searchTitle)){
it.remove();
return;
}//if
} //while
}//deletebook
public void deleteBorrower(){
String name;
Scanner scan = new Scanner(System.in);
System.out.println("Enter the name of the borrower you wish to delete: ");
name = scan.nextLine();
ListIterator it = borrowerList.listIterator();
while(it.hasNext()){
Borrower borrower = (Borrower) it.next();
if(borrower.name.equals(name)){
it.remove();
return;
}//if
} //while
}//deleteborrower
}//libraryBorrower class:
public class Borrower {
protected String name;
protected int libNumb;
public Borrower(String name, int libNumb){
this.name = name;
this.libNumb = libNumb;
public Borrower(){
@Override
public String toString(){
String result;
result = "Name: " + name + "\n";
result += "Library Number: " + libNumb + "\n";
return(result);
}Book:
public class Book {
protected String title;
protected String author;
protected int catNumber;
protected int noCopy;
public Book(String title, String author, int catNumber, int noCopy){
this.title = title;
this.author = author;
this.catNumber = catNumber;
this.noCopy = noCopy;
public Book(){
@Override
public String toString(){
String result;
result = "Title: " + title + "\n";
result += "Author: " + author + "\n";
result += "Catalogue number: " + catNumber + "\n";
result += "Number of copies: " + noCopy + "\n";
return(result);
}Well, i got so far as creating a new ArrayList!
What I am struggling with is searching an ArrayList using its inbuilt methods - do i have to use an iterator?
I want to ask the user to input a library number (no probs) then search the Borrowers ArrayList to find the Borrower with that library number. The i want to ask the user to input a book title, search the Book ArrayList and find the book with that title. Finally i want to add the two together to create the borrowing details.
Not much huh :) -
Arraylist isnt updating at the right position
Hi all
Im having a problem with arraylist
I have a custom ADT that stores all of my ap data (my stylesheet info)
what i am trying to do is when i click the save changes button, before the changes are saved i am putting my custom ADT into an array list
then i want to be able to traverse back through the arraylist to have an undo feature
however, everytime i add something to my arraylist, everything is becoming the same value
im using ar.add(pointervalue,myadt)
the pointervalue increments when every save is done
is this something to do with me needing to override my equals and hashcode on my custom adt?
i wouldnt expect it to be though as im using an int as my pointer value and not the actual value of the adt (and am i right in thinking arraylist always uses the int pointer as it isnt a map?)
anyway, can anyone help shed a little light on the subject, thanksas workSheet is defined at the start as it is used in
a few other methods.You have to see the difference between a reference to an object and the object itself.
i can see what your saying, but im not fully
understanding why when i update the worksheet adt,
why isnt it putting it in the arraylist as a new objectBecause this is not PHP, where objects are passed as copies. The list only gets a copy of the reference, not of the object. Both the list and "workSheet" are pointing to the same instance. You use only one instance of your worksheet in your program, that's why anything gets overwritten.
why does the array list update every one?It doesn't. There is only one object, and many references pointing to it. -
i want real time using servlets ,jsp ,javascript for maintaing the upload a file and how to create the excel file
ok,i understood that this site is not for coding.
could u please tell me how to write (give one idea),Translation : I understand but somehow I don't.
Anyway.. .here is my one idea for you
http://jakarta.apache.org/poi/
i also have one idea that is by using Bean ,but it
takes memory for every object for storing in
arraylist.
u give ur idea for meHonestly. I realize that English is not your first language but this rambly collection of "sentences" is unintelligable.
You did something.. with a Bean... and you are having problems with ArrayLists. What? Huh?
All that one can get from that is that your English is not good enough to recieve help in it or you simply have no idea of what you are doing in Java. I put my money on the latter. And please note that by the former I am NOT insulting you. If you cannot speak a language well enough to properly communicate then you had best stick to a language you can communicate in. -
Hi,
I'm trying to read a CSV text file into an arraylist.
I can read the text file fine, its just when it gets to the actual arraylist.add() part it just .. .. doesn't work. It can print the values from the CSV file no problem. I'm sure my syntax is fine, everything compiles. I've read it and double checked it and checked it again.
It just doesn't work .. I don't know why.
The arraylist I am trying to read into is
ArrayList<Customer> customers = new ArrayList<Customer>();Within other parts of the program I can read in dummy data, eg
customers.add(new Customer(01, "Jims Mowing", "16 Long Grass Street", "Thorndale", "123-4567", "[email protected]"));
but suffice to say, yes, it is kaput.
* READING THE CUSTOMER TEXT FILE INTO THE ARRAY LIST
private void custFileToArray ()
RectangleTUI results = new RectangleTUI(); // create results object
try
BufferedReader inputStream = new BufferedReader(new FileReader(PATHNAME + CUSTFILE));
System.out.println("Contents of file: " + CUSTFILE); // print heading
String line = inputStream.readLine(); // read first line
while (line !=null) // test for end of file (EOF)
results.loadCustFile(line);
line = inputStream.readLine(); // read next line
// close file
inputStream.close();
// catch any file open errors
catch(FileNotFoundException e)
System.out.println("Error opening file: " + CUSTFILE);
System.exit(0);
catch(NoSuchElementException e)
System.out.println("ATTENTION: One or more " + CUSTFILE + " records are missing data");
// catch any file reading errors
catch(IOException e)
System.out.println("Error reading from file: " + CUSTFILE);
System.exit(0);
System.out.println("File Reading Complete");
private void loadCustFile(String textLine)
String delimiters = ","; // set tokenizer delimiter
StringTokenizer RecordFields = new StringTokenizer(textLine,delimiters);
int cidNum = Integer.parseInt(RecordFields.nextToken()); // Customer ID
System.out.println(cidNum + " Hello I am a stupid piece of code. I don't like to work properly");
String cName = RecordFields.nextToken(); // Name
String cAdd = RecordFields.nextToken(); // Street Address
String cBurb = RecordFields.nextToken(); // Suburb
String cPhone = RecordFields.nextToken(); // Phone
String cEmail = RecordFields.nextToken(); // Email
customers.add(new Customer(cidNum, cName, cAdd, cBurb, cPhone, cEmail));
}Cowzor wrote:
Hi,
Cheers for the replies & the printStackTrace tip.
The thing is it's not actually throwing up any errors or crashing. It's acting as if everything is AOK - but since it then says there's nothig in the arraylist there must be a problem ... somewhere.
Sorry if I've mis-understood what you were saying
Here's the dummy data I'm using just incase it's at all relevant
200701,Jims Mowing,16 Long Grass Street,Thorndale,123-4567,[email protected]
200702,Chevy Racers,2 Raceway Drive,Boganville,123-4567,[email protected]
200703,Renta Dent,82 Airport Oaks Road,Airport Oaks,123-4567,[email protected]
200704,Discount Taxis,8 Poor Place,Otara,123-4567,[email protected]
u split contains of CSV file on basis of , (comma) and read it -
Hi!
I need a little help getting an ArrayList to work. I am refactoring some of the classes in one of the O'Reilly books for a class assignment. I believe that I cannot get my ArrayList to add elements into itself. I'm not quite sure what I'm doing wrong. I'll post the code below. The problem arises in the last part of the code (at least I think it does) where i can't get my variable "size" (see the "for loop" below) to be resolved. I have tried initializing the variable at the beginning of the entire class in which case I can get the file to compile to a class. But when I run the class, I still get an ArrayOutOfBounds exception letting me know that my array is still initialized to 1 when i believe that and my index is a larger number (the number I input into the console). the message I get from the command line is:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Error:
java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.ArrayList.get(ArrayList.java:326)
at MyFactorial.computeFactorialCacheB(MyFactorial.java:115) // this would be the second line of the "for" loop
at MyFactorial.main(MyFactorial.java:134)
Any help would be greatly appreciated. Thanks in advance.
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Here is my code
public static synchronized BigInteger computeFactorialCacheB(String s) {
private static int size;
ArrayList table = new ArrayList();
table.add(BigInteger.valueOf(1));
int x = 0;
try {
x = Integer.parseInt(s);
catch (NumberFormatException e) {
System.out.println("the number you enter must be an integer");
if (x<0) {
throw new IllegalArgumentException("x must not be a negative number");
else {
for(int size = table.size(); size <= x; size++);{
BigInteger lastfact = (BigInteger)table.get(size-1);
BigInteger nextfact = lastfact.multiply(BigInteger.valueOf(size));
table.add(nextfact);
return (BigInteger) table.get(size-1);
}Thanks for your reply.
As I said in my original posting, I am refactoring code from one of the O'Reilly books for an assignment. So no, this isn't all my code, just some of it (copyright is duly noted in my assignment).
The semicolon was a great cach (thanks!) I truly didn't see it. The issue of the "size" variable is what I am trying to solve. When I originally entered the code int my IDE (eclipse) the first declaration of int size inside the for loop was OK but subsequent references to it (still in the for loop) wouldn't resolve.
for(int size = table.size(); size <= x; size++){
BigInteger lastfact = (BigInteger)table.get(size-1);
BigInteger nextfact = lastfact.multiply(BigInteger.valueOf(size));
table.add(nextfact);Hence the experimentation with the "size" variable. The use of the ArrayList was one of the parameters of the assignment. I see what you mean by creating a new list each time. The purpose of the method is to return a factorial (n!) using a BigInteger. This loop is pretty much just as it came out of O'rilley. It seems to work fine in their rendition (I guess that's why they get to write books).
Tanks so much for your help. I'll refactor again and repost (probably tomorrow).
� regards! -
Well, im new to ArrayList and im having great trouble trying to figure things out,
this is what im supposed to do:
The Problem
A banking institution offers certificates of deposit (CD's) with a variety of interest rates, and maturities of 1, 3, 5, and 10 years. Interest is always compounded, daily, monthly, or quarterly.
Write a Java program that will compute the accumulated value (principal plus interest earned), at yearly intervals, of any number of such CD's. Assume that a year always consists of exactly 365 days.
Output will be a series of 10 annual reports:
Reports will be in table form with appropriate column headings. There will be one row of the table for each active CD, which will include all the data along with the accumulated value and total interest earned to data.
Each report will also print the total interest earned by all CDs for the current year, and total interest earned by all active CD�s to data.
Once a CD reaches maturity, it will stop earning interest and will not appear in any future reports. E.g., a CD with a maturity of 5 years will appear in the reports for years one through five, but not thereafter.
The CD Class
Begin by creating a class to model a CD. Each CD object "knows" its own principal, interest rate, maturity, and compounding mode (private instance variables). The class has �get� methods to return this data and a method to compute and return the accumulated value.
The CDList Class
Now create a class to maintain a list of CDs. You will need methods to add a CD to the list and to print the annual report.
The Driver (i.e., "Test") Class
Your test class or "driver" class will read data for any number of CDs from a file that I will supply. Each line of the file will contain the data � principal, interest rate (as an annual per cent), maturity, and compounding mode � for one CD.
First, tokenize each line read, create a CD object from the tokens, and add it to the list. Then print the reports.
Additional Specifications
Your CDList class must use an ArrayList as the principal (no pun intended) data structure.
Your test class is to read the data file one time only. No credit will be given for programs that read the data file more than once.
Make sure your program is well documented and adheres to the style conventions discussed in class.
Due date: Thursday, April 20th
Formula
The accumulated value (i.e., principal plus interest), A, is given by the formula:
r nt
A = p ( 1 + ���� )
n
where
p = principal
n = number of times compounded per year
r = annual interest rate, expressed as a decimal
t = elapsed time in years
now, im supposed to read data from a file, and whats inside the file is:
5000 5 8.25 quarterly
12000 10 10.80 daily
2000 5 7.30 quarterly
10000 3 5.55 monthly
2000 1 4.50 daily
5000 10 9.15 monthly
now, im totally lost, however, ive managed to do this so far:
import java.util.ArrayList;
import java.io.*;
import java.util.*;
class CD
private String time;
private double cdAmount;
private int cdMonths;
private double cdInterest;
public CD(String time, double cdAmount, int cdMonths, double cdInterest)
this.time = time;
this.cdAmount = cdAmount;
this.cdMonths = cdMonths;
this.cdInterest = cdInterest;
public String getTime()
return time;
public double CDAmount()
return cdAmount;
public int CDMonths()
return cdMonths;
public double CDInterest()
return cdInterest;
class CDlist
private ArrayList<CD> list;
public CDlist()
list = new ArrayList<CD>();
public void addList(CD info)
list.add(info);
}Please any help regarding this subject will be greatly appreciated.Ok, lets take this step by step,
it says that in the cd class im supposed to have:
Each CD object "knows" its own principal, interest rate, maturity, and compounding mode (private instance variables)"
1. i have 4 variables, am i missing something in the CD class?
2. the cdlist class is supposed to have this:
"Now create a class to maintain a list of CDs. You will need methods to add a CD to the list and to print the annual report."
i have created an empty list, do i need to add the 4 variables into the list ive created??
3. the test class says this:
"Your test class or "driver" class will read data for any number of CDs from a file that I will supply. Each line of the file will contain the data � principal, interest rate (as an annual per cent), maturity, and compounding mode � for one CD.
First, tokenize each line read, create a CD object from the tokens, and add it to the list. Then print the reports."
well i dont know how to do this, but ill try not to worry about this now -
ArrayList problem ....i can remove my object from my arrayList
hi all, i am going to remove a object from my array by using arrayList.However, it can`t work properly and did nth for me..i don`t know why...could anyone give me some suggestion and show me what i did wrong on my code ....i stated more detail next to my code...plesae help...
public class MusicCd
private String musicCdsTitle;
private int yearOfRelease;
public MusicCd()
musicCdsTitle = "";
yearOfRelease = 1900;
public MusicCd(String newMusicCdsTitle)
musicCdsTitle = newMusicCdsTitle;
//yearOfRelease = newYearOfRelease;
public MusicCd(String newMusicCdsTitle, int newYearOfRelease)
musicCdsTitle = newMusicCdsTitle;
yearOfRelease = newYearOfRelease;
public String getTitle()
return musicCdsTitle;
public int getYearOfRelease()
return yearOfRelease;
public void setTitle(String newMusicCdsTitle)
musicCdsTitle = newMusicCdsTitle;
public void setYearOfRelease(int newYearOfRelease)
yearOfRelease = newYearOfRelease;
public boolean equalsName(MusicCd otherCd)
if(otherCd == null)
return false;
else
return (musicCdsTitle.equals(otherCd.musicCdsTitle));
public String toString()
return("Music Cd`s Title: " + musicCdsTitle + "\t"
+ "Year of release: " + yearOfRelease + "\t");
import java.util.ArrayList;
import java.io.*;
public class MusicCdStore
ArrayList<MusicCd> MusicCdList;
public void insertCd()
MusicCdList = new ArrayList<MusicCd>( );
readOperation theRo = new readOperation();
MusicCd theCd;
int muiseCdsYearOfRelease;
String muiseCdsTitle;
while(true)
String continueInsertCd = "Y";
do
muiseCdsTitle = theRo.readString("Please enter your CD`s title : ");
muiseCdsYearOfRelease = theRo.readInt("Please enter your CD`s year of release : ");
MusicCdList.add(new MusicCd(muiseCdsTitle, muiseCdsYearOfRelease));
MusicCdList.trimToSize();
continueInsertCd = theRo.readString("Do you have another Cd ? (Y/N) : ");
}while(continueInsertCd.equals("Y") || continueInsertCd.equals("y") );
if(continueInsertCd.equals("N") || continueInsertCd.equals("n"));
//MusicCdList.add(new MusicCd(muiseCdsTitle, muiseCdsYearOfRelease));
break;
//System.out.println("You `ve an invalid input " + continueInsertCd + " Please enter (Y/N) only!!");
public void displayAllCd()
System.out.println("\nOur CD collection is: \n" );
System.out.println(toString());
public String toString( )
String result= " ";
for( MusicCd tempCd : MusicCdList)
result += tempCd.toString() + "\n";
return result;
public void searchingMusicCd()
readOperation theRo = new readOperation();
String keyword = theRo.readString("Enter a CD `s Title you are going to search : ") ;
ArrayList<MusicCd> results = searchForTitle(keyword );
System.out.println("The search results for " + keyword + " are:" );
for(MusicCd tempCd : results)
System.out.println( tempCd.toString() );
//encapsulate the A
public void removeCd()
readOperation theRo = new readOperation();
String keyword = theRo.readString("Please enter CD `s title you are going to remove : ") ;
ArrayList<MusicCd> removeMusicCdResult = new ArrayList<MusicCd>();
System.out.println("The CD that you just removed is " + keyword );
for(MusicCd tempCd : removeMusicCdResult)
System.out.println( tempCd.toString() );
//problem occurs here : i am so confused of how to remove the exactly stuff from my arrayList
//pls help
private ArrayList<MusicCd> removeCdForTitle(String removeCdsTitle)
MusicCd tempMusicCd = new MusicCd();
tempMusicCd.setTitle(removeCdsTitle);
// tempMusicCd.setTitle(removeCdsTitle);
//tempMusicCd.getTitle() = removeCdsTitle;
ArrayList<MusicCd> removeMusicCdResult = new ArrayList<MusicCd>();
for(MusicCd currentMusicCd : MusicCdList)
if((currentMusicCd.getTitle()).equals(tempMusicCd.getTitle()))
// removeMusicCdResult.remove(currentMusicCd);
MusicCdList.remove(currentMusicCd);
removeMusicCdResult.trimToSize();
return removeMusicCdResult;
private ArrayList<MusicCd> searchForTitle(String searchString)
ArrayList<MusicCd> searchResult = new ArrayList<MusicCd>();
for(MusicCd currentMusicCd : MusicCdList)
if((currentMusicCd.getTitle()).indexOf(searchString) != -1)
searchResult.add(currentMusicCd);
searchResult.trimToSize();
return searchResult;
import java.util.*;
public class MusicCdStoreEngine{
public static void main(String[] args)
MusicCdStore mcs = new MusicCdStore( );
mcs.insertCd();
//display the Cd that you just insert
mcs.displayAllCd();
mcs.removeCd();
mcs.displayAllCd();
mcs.searchingMusicCd();
//Acutally result
//Please enter your CD`s title : ivan
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : y
//Please enter your CD`s title : hero
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : n
//Our CD collection is:
// Music Cd`s Title: ivan Year of release: 1992
//Music Cd`s Title: hero Year of release: 1992
//Please enter CD `s title you are going to remove : hero
//The CD that you just removed is hero
//Our CD collection is:
// Music Cd`s Title: ivan Year of release: 1992
//Music Cd`s Title: hero Year of release: 1992
//Enter a CD `s Title you are going to search : hero
//The search results for hero are:
//Music Cd`s Title: hero Year of release: 1992
//>Exit code: 0
//Expected result
//Please enter your CD`s title : ivan
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : y
//Please enter your CD`s title : hero
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : n
//Our CD collection is:
// Music Cd`s Title: ivan Year of release: 1992
//Music Cd`s Title: hero Year of release: 1992
//Please enter CD `s title you are going to remove : hero
//The CD that you just removed is hero
//Our CD collection is:
// Music Cd`s Title: ivan Year of release: 1992
//Music Cd`s Title: hero Year of release: 1992<<-- it is not supposed to display cos i have deleted it from from array
//Enter a CD `s Title you are going to search : hero
//The search results for hero are:
//Music Cd`s Title: hero Year of release: 1992<<-- i should have get this reuslt...cos it is already delete from my array
//>Exit code: 0
import java.util.*;
public class readOperation{
public String readString(String userInstruction)
String aString = null;
try
Scanner scan = new Scanner(System.in);
System.out.print(userInstruction);
aString = scan.nextLine();
catch (NoSuchElementException e)
//if no line was found
System.out.println("\nNoSuchElementException error occurred (no line was found) " + e);
catch (IllegalStateException e)
// if this scanner is closed
System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
return aString;
public char readTheFirstChar(String userInstruction)
char aChar = ' ';
String strSelection = null;
try
//char charSelection;
Scanner scan = new Scanner(System.in);
System.out.print(userInstruction);
strSelection = scan.next();
aChar = strSelection.charAt(0);
catch (NoSuchElementException e)
//if no line was found
System.out.println("\nNoSuchElementException error occurred (no line was found) " + e);
catch (IllegalStateException e)
// if this scanner is closed
System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
return aChar;
public int readInt(String userInstruction) {
int aInt = 0;
try {
Scanner scan = new Scanner(System.in);
System.out.print(userInstruction);
aInt = scan.nextInt();
} catch (InputMismatchException e) {
System.out.println("\nInputMismatchException error occurred (the next token does not match the Integer regular expression, or is out of range) " + e);
} catch (NoSuchElementException e) {
System.out.println("\nNoSuchElementException error occurred (input is exhausted)" + e);
} catch (IllegalStateException e) {
System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
return aInt;
}//problem occurs hereI'm not sure that the problem does occur within the
removeCdForTitle() method.
Your main() method calls removeCd() which obtains the title of
the CD to be removed (keyword). But remoceCd() never
calls removeCdForTitle(), so nothing is ever removed. -
Problem at iteration (ArrayList)
I`e made a soft wich writes elements from an array list to a table.
int c=0;
for (int a=0;a<(tabela.getRowCount());a++)
for (int b=0;b<(tabela.getColumnCount());b++){
tabela.setValueAt(list.get(c),a,b);
where tabela is the Table and list is the ArrayList. This version put into each row the element from the first position of the array list (because c=0). When i run this version, there are no problems. But if I increment c at each step (to put the nex value from the arraylist to the next row) i get this error message:
Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index: 4, Size: 4
at java.util.ArrayList.RangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at BazaDeDate.creazaTabela(BazaDeDate.java:100)
at BazaDeDate.<init>(BazaDeDate.java:64)
at Fereastra$6.actionPerformed(Fereastra.java:151)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
This is how i increment c.
int c=0;
for (int a=0;a<(tabela.getRowCount());a++)
for (int b=0;b<(tabela.getColumnCount());b++){
tabela.setValueAt(list.get(c),a,b);
Thanks for any good suggestions.Really? you don't understand what "Array Index Out Of Bounds" means?
You've tried to access something outside of your list. Don't do that.
Figure out why your list contains fewer items than your table has slots for; or stop assuming there are enough.
Maybe you are looking for
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