Develop Reference

Text area exceeds the window area

I have wrote program in java the program is to convert from KM to miles and miles to KM the program works fine but the problem is in the result in text area exceeded the area so does not appear the full text below the code attached. so i want if it is reached at the end of line it goes to new line
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Converter extends JFrame implements ActionListener {
JLabel label = new JLabel("Distance : ");
JTextField input = new JTextField(10);
JButton button = new JButton("Convert");
JTextArea output = new JTextArea(10,15);
CheckboxGroup cbg = new CheckboxGroup();
Checkbox cb1 = new Checkbox("Convert MILES to KM", cbg, true);
Checkbox cb2 = new Checkbox("Convert KM to MILES", cbg, false);
public static void main(String args[]) {
Converter s = new Converter();
s.setVisible(true);
}
public Converter() {
setLayout(null);
setSize(300,400);
//left-down-width-hegiht
cb1.setBounds(60,30,150,30);
cb2.setBounds(60,60,150,30);
label.setBounds(30,90,120,30);
input.setBounds(90,95,170,20);
button.setBounds(100,130,90,30);
output.setBounds(45,168,200,165);
add(cb1);
add(cb2);
add(label);
add(input);
add(button);
add(output);
button.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
if (cb1.getState() ) {
if (e.getSource() == button) {
double d = Double.parseDouble(input.getText());
double d2 = d / 0.62;
String str2 = String.valueOf(d2);
output.setText(d + "miles equals to " + str2 + " kilometers");
}
}
if (cb2.getState()) {
if (e.getSource() == button){
double d = Double.parseDouble(input.getText());
double d2 = d * 0.62;
String str2 = String.valueOf(d2);
output.setText(d + " kilometers equals to " + str2 + " miles ");
}
}
}
}

If your goal is purely to have line wrapping on in the text area then you can make use of JTextArea's built-in function named setLineWrap.
Passing a true boolean value as a parameter to setLineWrap such as setLineWrap(true) will turn on line wrapping for the JTextArea component. Passing a false boolean value as a parameter will turn off line wrapping
In your code, it would be used as follows.
output.setLineWrap(true);
The Converter constructor will then look as follows.
public Converter() {
// Turn on line wrapping.
output.setLineWrap(true);
setLayout(null);
setSize(300, 400);
// left-down-width-hegiht
cb1.setBounds(60, 30, 150, 30);
cb2.setBounds(60, 60, 150, 30);
label.setBounds(30, 90, 120, 30);
input.setBounds(90, 95, 170, 20);
button.setBounds(100, 130, 90, 30);
output.setBounds(45, 168, 200, 165);
add(cb1);
add(cb2);
add(label);
add(input);
add(button);
add(output);
button.addActionListener(this);
}

How can I access variables outside of loop in Java?

So I have my if statements to search a .txt file for the currency codes that correspond to the country the user types in. I store those country codes in Strings called 'from' and 'to'. I need to access the results of the if statements which are stored in the 'from' and 'to' variables to plug into something later. When I try to use these in the line way down at the end it says Cannot find symbol 'from' and Cannot find symbol 'to'. How can I fix this?
//all my imports here
public class ExchangeApp {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(300,400);
frame.setTitle("Exchange App");
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(8, 2, 5, 3));
//GUI Elements
JLabel toLabel = new JLabel("To");
JTextField CurrencyTo = new JTextField(20);
JLabel fromLabel = new JLabel("From");
JTextField CurrencyFrom = new JTextField(20);
JLabel amountLabel = new JLabel("Amount");
JTextField AmountText = new JTextField(20);
JLabel displayLabel = new JLabel();
JLabel updateLabel = new JLabel();
JButton Calculate = new JButton("Calculate");
JButton Clear = new JButton("Clear");
//Add elements to panel
panel.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
panel.add(fromLabel);
panel.add(CurrencyFrom);
panel.add(toLabel);
panel.add(CurrencyTo);
panel.add(amountLabel);
panel.add(AmountText);
panel.add(Calculate);
panel.add(Clear);
panel.add(displayLabel);
panel.add(updateLabel);
//make visible
frame.add(panel);
frame.setVisible(true);
class calculateListener implements ActionListener{
#Override
public void actionPerformed(ActionEvent event){
if(event.getSource()==Calculate){
String line, from, to;
String fromString = CurrencyFrom.getText();
String toString = CurrencyTo.getText();
double amount = Double.parseDouble(AmountText.getText());
try{
//import text file
File inputFile = new File("currency.txt");
//create file scanner
Scanner input = new Scanner(inputFile);
try{
//skip first line
input.nextLine();
//while has next line
while(input.hasNextLine()){
//set line equal to entire line
line = input.nextLine();
String[] countryArray = line.split("\t");
//search for from
if(fromString.equals(countryArray[0])){
//set 'from' equal to that country code
from = countryArray[2];
//testing
System.out.println(from);
}
//search for to
if(toString.equals(countryArray[0])){
//set 'to' equal to that country code
to = countryArray[2];
System.out.println(to);
}
else{
displayLabel.setText("To country not found");
}
}//while loop
}//2nd try
finally{input.close();}
}//1st try
catch(IOException exception){
System.out.println(exception);
}//catch bracket
}//if bracket ****these 2 variables****
String address = "http://finance.yahoo.com/d/quotes.csv?e=.csv&f=sl1d1t1&s=" + from + to;
}//action bracket
}//class implements action listener bracket
ActionListener listener = new calculateListener();
Calculate.addActionListener(listener);
}//main bracket
}//class bracket

How can I output a user's information entered through a Java Swing GUI onto an excel sheet?

I am writing a program to help keep track of employee seating, however, I am having a difficult time getting the user's information that was captured by a Java Swing GUI to be printed onto an excel sheet. I am using apache POI in order to write to excel as well.
The program iterates through the rows on the excel sheet correctly, but it seems to delete the data that is supposed to be on the first row once the user wants to continue to enter more information. If the user enters information just ONCE (Desk number, employee name, the amount of employees at that desk), presses the JButton "Add To List", it prints the information on the first row like it is supposed to. If the user enters information more than once, it increments the amount of times the "Add To List" button is pressed, but only prints out the last input entered by the user leaving other previous instances of information being written onto the excel rows blank.
Is it a problem with the way the counter is being incremented? Or is it the textfields that need to be adjusted? I apologize for such a long post, but I am teaching myself how to program in java and this problem has been haunting me for a while.
This is my code so far:
import java.awt.EventQueue;
import java.awt.Window;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.util.*;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.*;
import java.io.*;
import javax.swing.DropMode;
public class userMenu {
private JFrame frmUtilizationSeatingReport; //JFrame being used
private JTextField txtDeskNum; //Text box that will hold the desk number
private JTextField txtEmployeeName; //Text box for employee name
private JTextField txtNumAtDesk; //Text box for the number of employees at that desk
public int rownum = 1; //My counter being used to increment the row in which input is being stored in
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
userMenu window = new userMenu();
window.frmUtilizationSeatingReport.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public userMenu() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frmUtilizationSeatingReport = new JFrame();
frmUtilizationSeatingReport.setTitle("Utilization Seating Report Program");
frmUtilizationSeatingReport.setBounds(100, 100, 436, 210);
frmUtilizationSeatingReport.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frmUtilizationSeatingReport.getContentPane().setLayout(null);
JLabel lblDeskNumber = new JLabel("Desk Number:");
lblDeskNumber.setBounds(20, 11, 163, 21);
frmUtilizationSeatingReport.getContentPane().add(lblDeskNumber);
txtDeskNum = new JTextField();
txtDeskNum.setBounds(42, 30, 121, 20);
frmUtilizationSeatingReport.getContentPane().add(txtDeskNum);
txtDeskNum.setColumns(10);
JLabel lblEmployeeName = new JLabel("Employee Name:");
lblEmployeeName.setBounds(20, 55, 163, 21);
frmUtilizationSeatingReport.getContentPane().add(lblEmployeeName);
txtEmployeeName = new JTextField();
txtEmployeeName.setBounds(42, 73, 121, 20);
frmUtilizationSeatingReport.getContentPane().add(txtEmployeeName);
txtEmployeeName.setColumns(10);
JLabel lblNumberOfEmployees = new JLabel("Number of Employees at Desk:");
lblNumberOfEmployees.setBounds(20, 96, 281, 21);
frmUtilizationSeatingReport.getContentPane().add(lblNumberOfEmployees);
txtNumAtDesk = new JTextField();
txtNumAtDesk.setBounds(42, 115, 121, 20);
frmUtilizationSeatingReport.getContentPane().add(txtNumAtDesk);
txtNumAtDesk.setColumns(10);
JButton btnAdd = new JButton("Add To List");
btnAdd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent b) {
String deskNumber = ""; //Will take the desk number in as a string
int empsAtDesk = 0; //The number of employees at the desk as an int
String employeeName = ""; //Employee Name
boolean keepRunning = true;
deskNumber = txtDeskNum.getText();
empsAtDesk = Integer.parseInt(txtNumAtDesk.getText());
employeeName = txtEmployeeName.getText();
//Blank workbook
HSSFWorkbook workbook = new HSSFWorkbook();
//Blank sheet
HSSFSheet sheet = workbook.createSheet("Seating Details");
//create heading
Row rowHeading = sheet.createRow(0);
rowHeading.createCell(0).setCellValue("Desk:");
rowHeading.createCell(1).setCellValue("Employee(s)Name:");
rowHeading.createCell(2).setCellValue("Number At Desk:");
//Create 'total' headings
Row rowtotal = sheet.createRow(71);
rowtotal.createCell(0).setCellValue("Total:");
CellStyle stylerowtotal = workbook.createCellStyle();
Font totalfonts = workbook.createFont();
totalfonts.setBold(true);
totalfonts.setFontName(HSSFFont.FONT_ARIAL);
totalfonts.setFontHeightInPoints((short) 11);
stylerowtotal.setFont(totalfonts);
stylerowtotal.setVerticalAlignment(CellStyle.ALIGN_CENTER);
rowtotal.getCell(0).setCellStyle(stylerowtotal);
Row rowpercent = sheet.createRow(72);
rowpercent.createCell(0).setCellValue("Total %/Day:");
stylerowtotal = workbook.createCellStyle();
totalfonts = workbook.createFont();
totalfonts.setBold(true);
totalfonts.setFontName(HSSFFont.FONT_ARIAL);
totalfonts.setFontHeightInPoints((short) 11);
stylerowtotal.setFont(totalfonts);
stylerowtotal.setVerticalAlignment(CellStyle.ALIGN_CENTER);
rowpercent.getCell(0).setCellStyle(stylerowtotal);
Row percentMTh = sheet.createRow(73);
percentMTh.createCell(0).setCellValue("Total %/Week M-Th:");
stylerowtotal = workbook.createCellStyle();
totalfonts = workbook.createFont();
totalfonts.setBold(true);
totalfonts.setFontName(HSSFFont.FONT_ARIAL);
totalfonts.setFontHeightInPoints((short) 11);
stylerowtotal.setFont(totalfonts);
stylerowtotal.setVerticalAlignment(CellStyle.ALIGN_CENTER);
percentMTh.getCell(0).setCellStyle(stylerowtotal);
Row percentMFri = sheet.createRow(74);
percentMFri.createCell(0).setCellValue("Total %/Week M-F:");
stylerowtotal = workbook.createCellStyle();
totalfonts = workbook.createFont();
totalfonts.setBold(true);
totalfonts.setFontName(HSSFFont.FONT_ARIAL);
totalfonts.setFontHeightInPoints((short) 11);
stylerowtotal.setFont(totalfonts);
stylerowtotal.setVerticalAlignment(CellStyle.ALIGN_CENTER);
percentMFri.getCell(0).setCellStyle(stylerowtotal);
Row seatsAvai = sheet.createRow(75);
seatsAvai.createCell(0).setCellValue("Total Seats Available:");
stylerowtotal = workbook.createCellStyle();
totalfonts = workbook.createFont();
totalfonts.setBold(true);
totalfonts.setFontName(HSSFFont.FONT_ARIAL);
totalfonts.setFontHeightInPoints((short) 11);
stylerowtotal.setFont(totalfonts);
stylerowtotal.setVerticalAlignment(CellStyle.ALIGN_CENTER);
seatsAvai.getCell(0).setCellStyle(stylerowtotal);
//Create Cell Formulas
//Total number of employees at a desk cell formula
rowtotal.createCell(2).setCellFormula("SUM(C2:C71)");
//Total percentage for the day
rowpercent.createCell(2).setCellFormula("(SUM(C2:C71) / 78) * 100");
//Font size and style loop for my headers
for(int i = 0; i < 3; i++)
{
CellStyle stylerowHeading = workbook.createCellStyle();
Font font = workbook.createFont();
font.setBold(true);
font.setFontName(HSSFFont.FONT_ARIAL);
font.setFontHeightInPoints((short) 11);
stylerowHeading.setFont(font);
stylerowHeading.setVerticalAlignment(CellStyle.ALIGN_CENTER);
rowHeading.getCell(i).setCellStyle(stylerowHeading);
}
//This data needs to be written (Object[])
Map <String, Object[]> data = new TreeMap<String, Object[]>();
data.put("5", new Object[] {deskNumber, employeeName, empsAtDesk});
if(keepRunning){
//Iterate over data and write to sheet
Set<String> keyset = data.keySet();
for(String Key : keyset)
{
Row row = sheet.createRow(rownum++);
Object [] objArr = data.get(Key);
int cellnum = 0;
for(Object obj : objArr)
{
Cell cell = row.createCell(cellnum++);
if(obj instanceof String)
{
cell.setCellValue((String)obj);
}
else if(obj instanceof Integer)
{
cell.setCellValue((Integer)obj);
}
}
//Auto size my columns that will be filled out with user input info.
for (int i = 0; i < 3; i++)
{
sheet.autoSizeColumn(i);
}
} //top for loop brace
try{
//save to excel file
FileOutputStream out = new FileOutputStream(new File("Employee Seating Report.xls"));
workbook.write(out);
out.flush();
out.close();
workbook.close();
System.out.println("Excel Written Succesfully..." + '\n');
} catch (FileNotFoundException e1) {
e1.printStackTrace();
} catch (IOException e1){
e1.printStackTrace();
} catch (Exception e1) {
System.out.println(e1.getMessage());
}
//Empty text fields once user presses "Add To List" button
txtDeskNum.setText("");
txtEmployeeName.setText("");
txtNumAtDesk.setText("");
}//If statement end brace
}//Public void end brace
});
btnAdd.setBounds(214, 42, 129, 23);
frmUtilizationSeatingReport.getContentPane().add(btnAdd);
JButton btnExit = new JButton("End Program");
btnExit.addActionListener(new ActionListener() {
//If the user presses the"End Program" button, close the program.
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
btnExit.setBounds(214, 95, 129, 23);
frmUtilizationSeatingReport.getContentPane().add(btnExit);
}
}

You are creating your workbook inside your addActionListener and writing a new Excel file in it, so it will always overwrite the previous written data.
Try collecting all the data to a List of objects EmployeeDesk on click of your button btnAdd and create a new button that creates the workbook and writes the data from your list to your Excel, so you'll have a new button btnSave that creates the Excel file and writes everthing.

I'm not an expert of the .xls format and haven't used it but i've written to csv files and you can use the java standard library to do so fairly simply. Maybe a jtable would remove some of the ambiguity you have with creating rows columns and headers. It would certainly be less verbose.

delete previous content from JTable every time button event happens

I'm having a hard time removing data from my JTable. I've tried JTable .repaint(), setRowCount(0) , also model.removeRow(). I created print statements to see the row count when using setRowCount and the rows do become 0 however my table does not update. This is the last part of this project I need to implement. I'm not sure why my table isn't updating because I am altering the model with removeRow as well as setRowCount. If you guys could guide me in the right direction I would appreciate it.
public class TemplateGui extends JFrame {
private final ButtonGroup buttonGroup = new ButtonGroup();
private JTextField textField;
private static String [] sortedRoles_Flags,finalFlagsArr,finalHSArr;
private static String finalFlags="",finalHS="",columnToConvert="Result";
private Vector<String> SF,HS,column;
private JTable hotelSecurityTable,securityFlagsTable;
private DefaultTableModel hsTableModel,sfTableModel;
public TemplateGui(){
super("Galaxy Template Generator V1.0");
//column name
column = new Vector(Arrays.asList(columnToConvert));
getContentPane().setForeground(new Color(0, 0, 0));
getContentPane().setLayout(null);
getContentPane().setBackground(new Color(51, 51, 51));
//radio buttons
JRadioButton rdbtnNewRadioButton = new JRadioButton("Central User ");
rdbtnNewRadioButton.setFont(new Font("Tahoma", Font.BOLD, 11));
rdbtnNewRadioButton.setBackground(Color.WHITE);
buttonGroup.add(rdbtnNewRadioButton);
rdbtnNewRadioButton.setBounds(222, 75, 127, 36);
getContentPane().add(rdbtnNewRadioButton);
final JRadioButton rdbtnPropertyUser = new JRadioButton("Property User");
rdbtnPropertyUser.setFont(new Font("Tahoma", Font.BOLD, 11));
rdbtnPropertyUser.setBackground(Color.WHITE);
buttonGroup.add(rdbtnPropertyUser);
rdbtnPropertyUser.setBounds(222, 38, 127, 34);
getContentPane().add(rdbtnPropertyUser);
textField = new JTextField();
textField.setFont(new Font("Tahoma", Font.BOLD, 18));
textField.setBounds(10, 35, 53, 34);
getContentPane().add(textField);
textField.setColumns(10);
JLabel lblHotelSecurity = new JLabel("Hotel Security (H S)");
lblHotelSecurity.setHorizontalAlignment(SwingConstants.CENTER);
lblHotelSecurity.setFont(new Font("Tahoma", Font.BOLD, 13));
lblHotelSecurity.setBounds(10, 144, 189, 23);
lblHotelSecurity.setBackground(new Color(204, 204, 204));
lblHotelSecurity.setOpaque(true);
getContentPane().add(lblHotelSecurity);
JLabel label = new JLabel("Security Flags (S F)");
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setFont(new Font("Tahoma", Font.BOLD, 13));
label.setBounds(222, 144, 372, 23);
label.setBackground(new Color(204, 204, 204));
label.setOpaque(true);
getContentPane().add(label);
JLabel lblEnterTemplateCode = new JLabel("ENTER TEMPLATE CODE");
lblEnterTemplateCode.setForeground(new Color(255, 255, 255));
lblEnterTemplateCode.setFont(new Font("Tahoma", Font.BOLD, 14));
lblEnterTemplateCode.setBounds(10, 9, 175, 23);
getContentPane().add(lblEnterTemplateCode);
JLabel lblSelectUserRole = new JLabel("SELECT USER ROLE LEVEL");
lblSelectUserRole.setForeground(new Color(255, 255, 255));
lblSelectUserRole.setFont(new Font("Tahoma", Font.BOLD, 14));
lblSelectUserRole.setBounds(222, 13, 195, 14);
getContentPane().add(lblSelectUserRole);
//Submit button action
Button button = new Button("Generate Template");
button.setFont(new Font("Dialog", Font.BOLD, 12));
button.setBackground(new Color(102, 255, 102));
button.setForeground(Color.BLACK);
button.setBounds(467, 83, 127, 41);
getContentPane().add(button);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Query excell = new Query();
//get template text
String template = textField.getText().toUpperCase();
System.out.println(template);
if(rdbtnPropertyUser.isSelected()){
try {
//property user was selected
excell.runProcess(1);
System.out.println("you selected Property user");
} catch (IOException e) {
e.printStackTrace();
}
}
else{
try {
//Central User was selected
excell.runProcess(2);
System.out.println("you selected central user");
} catch (IOException e) {
e.printStackTrace();
}
}
System.out.println("NOW WERE HERE");
//get static variables from Excel Query
for(int i = 0; i< Query.sortedGF.length; i++)
{
if(Query.sortedGF[i].contains(template)){
sortedRoles_Flags =Query.sortedGF[i].split(" ");
System.out.println("THIS RAN"+" :"+i);
break;
}
}
//add data to table
int j=1;
int sizeOfFlags = Query.securityFlags.length;
//Add HS to FinalHS Variable only if Yes
for(int i=0;i< sortedRoles_Flags.length+1-sizeOfFlags;i++)
{
if(sortedRoles_Flags[i].matches("Y|y|Y\\?|\\?Y|y\\?|\\?y"))
{
System.out.println("Hotel security:"+" "+sortedRoles_Flags[i]+" HS Added: "+Query.hotelSecurity[i]);
finalHS += Query.hotelSecurity[i]+"+";
System.out.println("Hotel security:"+" "+finalHS);
}
}
//add Security Flags to Final Flags
for(int i=(sortedRoles_Flags.length-sizeOfFlags+1);i< sortedRoles_Flags.length;i++)
{
finalFlags += Query.securityFlags[j]+"\t\t: "+ sortedRoles_Flags[i]+" + ";
j++;
}
//Leave open just incase they would prefer a text file for template in which case we just write it
System.out.println(finalFlags);
System.out.println(finalHS);
//Convert to String Arrays in order to add to our JTable
finalFlagsArr= finalFlags.split("\\+");
finalHSArr = finalHS.split("\\+");
for(int i=0; i <finalHSArr.length;i++)
finalHSArr[i].replaceAll(" ","");
hsTableModel.setRowCount(0);
for (String row : finalHSArr) {
hsTableModel.addRow(new Object[]{row});
}
sfTableModel.setRowCount(0);
for (String row : finalFlagsArr) {
sfTableModel.addRow(new Object[]{row});
}
}
});
//scroll panes for flags
JScrollPane scrollPaneHS = new JScrollPane();
scrollPaneHS.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPaneHS.setBounds(10, 170, 189, 185);
getContentPane().add(scrollPaneHS);
JScrollPane scrollPaneSF = new JScrollPane();
scrollPaneSF.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
scrollPaneSF.setBounds(222, 170, 372, 187);
getContentPane().add(scrollPaneSF);
//tables for updates
hsTableModel = new DefaultTableModel(HS,column);
hotelSecurityTable = new JTable(hsTableModel);
hotelSecurityTable.setBackground(new Color(255, 255, 255));
scrollPaneHS.setViewportView(hotelSecurityTable);
sfTableModel = new DefaultTableModel(SF,column);
securityFlagsTable = new JTable(sfTableModel);
scrollPaneSF.setViewportView(securityFlagsTable);
}
}
Update
my latest attempt. It seemed to work but not the second time around.
if(hsTableModel.getRowCount() !=0 && sfTableModel.getRowCount() !=0){
for(int i=0; i<hsTableModel.getRowCount();i++)
hsTableModel.removeRow(i);
for(int i=0; i<sfTableModel.getRowCount();i++)
sfTableModel.removeRow(i);
sfTableModel.fireTableRowsDeleted(0, sfTableModel.getRowCount()-1);
hsTableModel.fireTableRowsDeleted(0, hsTableModel.getRowCount()-1);
}

when using setRowCount and the rows do become 0 however my table does not update.
Since you are using a DefaultTableModel, the setRowCount(0) is the proper method to use to clear the model of all the entries. The should automatically repaint itself.
Create a simple SSCCE that demonstrates your problem. The SSCCE should consist of a JTable with data, and then a JButton to invoke the setRowCount() method.
Prove to yourself that the basic concept works and then determine why you real code doesn't. If the table does not repaint then it usually means you are invoking the setRowCount() method on a TableModel that has NOT be added to the JTable that is visible on the GUI.
Also, don't:
use Button. You should be using a JButton
use a null layout. Swing was designed to be used with Layout Managers.

setRowCount(0) works.
I was forgetting to reset the string Values of
finalHS =""; finalFlags=""; Therefore the table was printing out the values stored in the variable.
I had the variables obtain their data through += Method as seen below.
Next time I will SSCCE before posting.
for(int i=0;i< sortedRoles_Flags.length+1-sizeOfFlags;i++)
{
if(sortedRoles_Flags[i].matches("Y|y|Y\\?|\\?Y|y\\?|\\?y"))
{
System.out.println("Hotel security:"+" "+sortedRoles_Flags[i]+" HS Added: "+Query.hotelSecurity[i]);
finalHS += Query.hotelSecurity[i]+"+";
System.out.println("Hotel security:"+" "+finalHS);
}
}
//add Security Flags to Final Flags
for(int i=(sortedRoles_Flags.length-sizeOfFlags+1);i< sortedRoles_Flags.length;i++)
{
finalFlags += Query.securityFlags[j]+"\t\t: "+ sortedRoles_Flags[i]+" + ";
j++;
}

How To Keep Size Of JTextArea constant?

I'm using an object of JTextArea in my application which deals with sending sms.
I've used a DocumentFilter so as to allow only 160 characters to be typed in the textarea but now, I want the size of the textarea to be constant. it goes on increasing if I keep writing on the same line without pressing 'enter' key or even when I keep on pressing only Enter key. I tried once using 'scrollbar' too but the problem remains same. Suggest me something over this. Below is my code. Please check it.
class Send_sms extends JPanel implements ActionListener,DocumentListener
{
JButton send;
JTextArea smst;
JLabel title,limit;
JPanel mainp,titlep,sendp,wrap,titlewrap,blankp1,blankp2,sendwrap;
JScrollPane scroll;
Border br,blackbr;
Boolean flag = false;
PlainDocument plane;
public static final int LINES = 4;
public static final int CHAR_PER_LINE = 40;
//character limit 160 for a sms
public Send_sms()
{
br = BorderFactory.createLineBorder(Color.RED);
blackbr = BorderFactory.createEtchedBorder(EtchedBorder.RAISED,Color.DARK_GRAY,Color.GRAY);
setBorder(blackbr);
title = new JLabel("Enter the text you want to send!");
title.setFont(new Font("",Font.BOLD,17));
limit = new JLabel(""+charCount+" Characters");
smst = new JTextArea(LINES,CHAR_PER_LINE);
smst.setSize(100,100);
plane = (PlainDocument)smst.getDocument();
//adding DocumentSizeFilter 2 keep track of characters entered
plane.setDocumentFilter(new DocumentSizeFilter(charCount));
plane.addDocumentListener(this);
send = new JButton("Send");
send.setToolTipText("Click Here To Send SMS");
send.addActionListener(this);
//scroll = new JScrollPane(smst);
//scroll.setPreferredSize(new Dimension(200,200));
//scroll.setVerticalScrollBarPolicy(null);
//scroll.setHorizontalScrollBarPolicy(null);
smst.setBorder(br);
blankp1 = new JPanel();
blankp2 = new JPanel();
titlep = new JPanel(new FlowLayout(FlowLayout.CENTER));
titlewrap = new JPanel(new GridLayout(2,1));
mainp = new JPanel(new BorderLayout());
sendwrap = new JPanel(new GridLayout(3,1));
sendp = new JPanel(new FlowLayout(FlowLayout.CENTER));
wrap = new JPanel(new BorderLayout());
titlep.add(title);
titlewrap.add(titlep);
titlewrap.add(blankp1);
sendp.add(send);
sendwrap.add(limit);
sendwrap.add(blankp2);
sendwrap.add(sendp);
wrap.add(smst,BorderLayout.CENTER);
mainp.add(titlewrap,BorderLayout.NORTH);
mainp.add(wrap,BorderLayout.CENTER);
mainp.add(sendwrap,BorderLayout.SOUTH);
add(mainp);
}
public void actionPerformed(ActionEvent e)
{
Vector<Vector<String>> info = new Vector<Vector<String>> ();
Vector<String> numbers = new Vector<String>();
if(e.getSource() == send)
{
//Call a function to send he message to all the clients using text
//charCount = 165;
String msg = smst.getText();
if(msg.length() == 0)
JOptionPane.showMessageDialog(null,"Please Enter Message","Error",JOptionPane.ERROR_MESSAGE);
else
{
// System.out.println("Message:"+msg);
Viewdata frame = new Viewdata(msg);
limit.setText(""+charCount+" Characters");
charCount = 160;
}
}
}
public void insertUpdate(DocumentEvent e)
{
System.out.println("The legth:(insert) "+e.getLength());
for(int i = 0;i<e.getLength(); i++)
{
if(charCount >0)
charCount--;
else
break;
}
limit.setText(""+charCount+" Characters");
}
public void removeUpdate(DocumentEvent e)
{
//System.out.println("The legth(remove): "+e.getLength());
for(int i = 0;i<e.getLength(); i++)
{
charCount++;
}
limit.setText(""+charCount+" Characters");
}
public void changedUpdate(DocumentEvent e)
{
//System.out.println("The legth(change): "+e.getLength());
}
}//end Send_sms

Sound like you are creating the text area using
JTextArea textArea = new JTextArea();
When using this format the text area doesn't have a preferred size so it keeps on growing. If you use:
JTextArea textArea = new JTextArea(2, 30);
JScrollPane scrollPane = new JScrollPane( textArea );
Then the text area will have a preferred size of 2 rows and (roughly) 30 columns. As you type when you exceed the preferred width the horizontal scrollbar will appear. Or if you turn on wrapping, then the text will wrap and a vertical scrollbar will appear.

you need to specify:
textArea.setColumns (160);
textArea.setLineWrap (true);
textArea.setWrapStyleWord (false); //default
But the real problem is that you allow to input more than 160 characters. You need to create some kind of validator which will skip all inputed characters when there are already 160 characters written.

Initialise the textArea with a document that extends PlainDocument and in the insertString method limit the characters to 160