Issue with setting float point in Textfield

Question

hi
i have an issue with float input in a textfield.
what i want to do is.
when the user start typing numerics it should accept from right hand side and keep appending value from right hand side.
for ex
if i want to enter 123.45
user starts entering
1 then it should display as 0.01
2 then it should display as 0.12
3 then it should display as 1.23
4 then it should display as 12.34
5 then it should display as 123.45
to achive this i have written the code as below
public class Test{
     public static void main(String[] a){
     try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
DecimalFormat format = new DecimalFormat();
format.setGroupingUsed(true);
format.setGroupingSize(3);
format.setParseIntegerOnly(false);
JFrame f = new JFrame("Numeric Text Field Example");
final DecimalFormateGen tf = new DecimalFormateGen(10, format);
// tf.setValue((double) 123456.789);
tf.setHorizontalAlignment(SwingConstants.RIGHT);
JLabel lbl = new JLabel("Type a number: ");
f.getContentPane().add(tf, "East");
f.getContentPane().add(lbl, "West");
tf.addKeyListener(new KeyAdapter(){
     public void keyReleased(KeyEvent ke){
          char ch = ke.getKeyChar();
          char key;
          int finalres =0;
          String str,str1 = null,str2 =null,str3 = null,str4= null;
          if(ke.getKeyChar() == KeyEvent.VK_0 || ke.getKeyChar() == KeyEvent.VK_0 ||
                    ke.getKeyChar() == KeyEvent.VK_0 || ke.getKeyChar() == KeyEvent.VK_1 || ke.getKeyChar() == KeyEvent.VK_2 ||
                         ke.getKeyChar() == KeyEvent.VK_3 || ke.getKeyChar() == KeyEvent.VK_4 || ke.getKeyChar() == KeyEvent.VK_5 ||
                         ke.getKeyChar() == KeyEvent.VK_6 || ke.getKeyChar() == KeyEvent.VK_7 || ke.getKeyChar() == KeyEvent.VK_8 ||
                         ke.getKeyChar() == KeyEvent.VK_9 ){
               double value1 = Double.parseDouble(tf.getText());
               int position = tf.getCaretPosition();
               if(tf.getText().length() == 1){
                    if(tf.getText() != null || tf.getText() != ""){
                    value1 = value1 / 100;
                    tf.setText(String.valueOf(value1));
               /*else if(tf.getText().length() == 3){
                    str = tf.getText();
                    for(int i=0;i<str.length();i++){
                         if(str.charAt(i) == '.'){
                              str1 = str.substring(0,i);
                              str2 = str.substring(i+1,str.length()-1);
                              break;
                    key = ke.getKeyChar();
                    finalres = calculate.calculate1(str2,key);
                    str3 = merge.merge1(str1,finalres);
                    tf.setText(str3);
                    System.out.println(key);
                    System.out.println(str1);
                    System.out.println(str2);
               else{
                    value1 = Float.parseFloat(tf.getText());
                    value1 = value1*10;
                    tf.setText(String.valueOf(value1));
tf.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
try {
tf.normalize();
Long l = tf.getLongValue();
System.out.println("Value is (Long)" + l);
} catch (ParseException e1) {
try {
Double d = tf.getDoubleValue();
System.out.println("Value is (Double)" + d);
} catch (ParseException e2) {
System.out.println(e2);
f.pack();
f.setVisible(true);
import javax.swing.JTextField;
* Created on May 25, 2005
* TODO To change the template for this generated file go to
* Window - Preferences - Java - Code Style - Code Templates
* @author jagjeevanreddyg
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.PlainDocument;
import javax.swing.text.AbstractDocument.Content;
public class DecimalFormateGen extends JTextField implements
NumericPlainDocument.InsertErrorListener {
     public DecimalFormateGen() {
     this(null, 0, null);
     public DecimalFormateGen(String text, int columns, DecimalFormat format) {
     super(null, text, columns);
     NumericPlainDocument numericDoc = (NumericPlainDocument) getDocument();
     if (format != null) {
     numericDoc.setFormat(format);
     numericDoc.addInsertErrorListener(this);
     public DecimalFormateGen(int columns, DecimalFormat format) {
     this(null, columns, format);
     public DecimalFormateGen(String text) {
     this(text, 0, null);
     public DecimalFormateGen(String text, int columns) {
     this(text, columns, null);
     public void setFormat(DecimalFormat format) {
     ((NumericPlainDocument) getDocument()).setFormat(format);
     public DecimalFormat getFormat() {
     return ((NumericPlainDocument) getDocument()).getFormat();
     public void formatChanged() {
     // Notify change of format attributes.
     setFormat(getFormat());
     // Methods to get the field value
     public Long getLongValue() throws ParseException {
     return ((NumericPlainDocument) getDocument()).getLongValue();
     public Double getDoubleValue() throws ParseException {
     return ((NumericPlainDocument) getDocument()).getDoubleValue();
     public Number getNumberValue() throws ParseException {
     return ((NumericPlainDocument) getDocument()).getNumberValue();
     // Methods to install numeric values
     public void setValue(Number number) {
     setText(getFormat().format(number));
     public void setValue(long l) {
     setText(getFormat().format(l));
     public void setValue(double d) {
     setText(getFormat().format(d));
     public void normalize() throws ParseException {
     // format the value according to the format string
     setText(getFormat().format(getNumberValue()));
     // Override to handle insertion error
     public void insertFailed(NumericPlainDocument doc, int offset, String str,
     AttributeSet a) {
     // By default, just beep
     Toolkit.getDefaultToolkit().beep();
     // Method to create default model
     protected Document createDefaultModel() {
     return new NumericPlainDocument();
     // Test code
     public static void main(String[] args) {
     try {
     UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
     } catch (Exception evt) {}
     DecimalFormat format = new DecimalFormat("#,###.###");
     format.setGroupingUsed(true);
     format.setGroupingSize(3);
     format.setParseIntegerOnly(false);
     JFrame f = new JFrame("Numeric Text Field Example");
     final DecimalFormateGen tf = new DecimalFormateGen(10, format);
     tf.setValue((double) 123456.789);
     JLabel lbl = new JLabel("Type a number: ");
     f.getContentPane().add(tf, "East");
     f.getContentPane().add(lbl, "West");
     tf.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent evt) {
     try {
     tf.normalize();
     Long l = tf.getLongValue();
     System.out.println("Value is (Long)" + l);
     } catch (ParseException e1) {
     try {
     Double d = tf.getDoubleValue();
     System.out.println("Value is (Double)" + d);
     } catch (ParseException e2) {
     System.out.println(e2);
     f.pack();
     f.setVisible(true);
     class NumericPlainDocument extends PlainDocument {
     public NumericPlainDocument() {
     setFormat(null);
     public NumericPlainDocument(DecimalFormat format) {
     setFormat(format);
     public NumericPlainDocument(AbstractDocument.Content content,
     DecimalFormat format) {
     super(content);
     setFormat(format);
     try {
     format
     .parseObject(content.getString(0, content.length()), parsePos);
     } catch (Exception e) {
     throw new IllegalArgumentException(
     "Initial content not a valid number");
     if (parsePos.getIndex() != content.length() - 1) {
     throw new IllegalArgumentException(
     "Initial content not a valid number");
     public void setFormat(DecimalFormat fmt) {
     this.format = fmt != null ? fmt : (DecimalFormat) defaultFormat.clone();
     decimalSeparator = format.getDecimalFormatSymbols()
     .getDecimalSeparator();
     groupingSeparator = format.getDecimalFormatSymbols()
     .getGroupingSeparator();
     positivePrefix = format.getPositivePrefix();
     positivePrefixLen = positivePrefix.length();
     negativePrefix = format.getNegativePrefix();
     negativePrefixLen = negativePrefix.length();
     positiveSuffix = format.getPositiveSuffix();
     positiveSuffixLen = positiveSuffix.length();
     negativeSuffix = format.getNegativeSuffix();
     negativeSuffixLen = negativeSuffix.length();
     public DecimalFormat getFormat() {
     return format;
     public Number getNumberValue() throws ParseException {
     try {
     String content = getText(0, getLength());
     parsePos.setIndex(0);
     Number result = format.parse(content, parsePos);
     if (parsePos.getIndex() != getLength()) {
     throw new ParseException("Not a valid number: " + content, 0);
     return result;
     } catch (BadLocationException e) {
     throw new ParseException("Not a valid number", 0);
     public Long getLongValue() throws ParseException {
     Number result = getNumberValue();
     if ((result instanceof Long) == false) {
     throw new ParseException("Not a valid long", 0);
     return (Long) result;
     public Double getDoubleValue() throws ParseException {
     Number result = getNumberValue();
     if ((result instanceof Long) == false
     && (result instanceof Double) == false) {
     throw new ParseException("Not a valid double", 0);
     if (result instanceof Long) {
     result = new Double(result.doubleValue());
     return (Double) result;
     public void insertString(int offset, String str, AttributeSet a)
     throws BadLocationException {
     if (str == null || str.length() == 0) {
     return;
     Content content = getContent();
     int length = content.length();
     int originalLength = length;
     parsePos.setIndex(0);
     // Create the result of inserting the new data,
     // but ignore the trailing newline
     String targetString = content.getString(0, offset) + str
     + content.getString(offset, length - offset - 1);
     // Parse the input string and check for errors
     do {
     boolean gotPositive = targetString.startsWith(positivePrefix);
     boolean gotNegative = targetString.startsWith(negativePrefix);
     length = targetString.length();
     // If we have a valid prefix, the parse fails if the
     // suffix is not present and the error is reported
     // at index 0. So, we need to add the appropriate
     // suffix if it is not present at this point.
     if (gotPositive == true || gotNegative == true) {
     String suffix;
     int suffixLength;
     int prefixLength;
     if (gotPositive == true && gotNegative == true) {
     // This happens if one is the leading part of
     // the other - e.g. if one is "(" and the other "(("
     if (positivePrefixLen > negativePrefixLen) {
     gotNegative = false;
     } else {
     gotPositive = false;
     if (gotPositive == true) {
     suffix = positiveSuffix;
     suffixLength = positiveSuffixLen;
     prefixLength = positivePrefixLen;
     } else {
     // Must have the negative prefix
     suffix = negativeSuffix;
     suffixLength = negativeSuffixLen;
     prefixLength = negativePrefixLen;
     // If the string consists of the prefix alone,
     // do nothing, or the result won't parse.
     if (length == prefixLength) {
     break;
     // We can't just add the suffix, because part of it
     // may already be there. For example, suppose the
     // negative prefix is "(" and the negative suffix is
     // "$)". If the user has typed "(345$", then it is not
     // correct to add "$)". Instead, only the missing part
     // should be added, in this case ")".
     if (targetString.endsWith(suffix) == false) {
     int i;
     for (i = suffixLength - 1; i > 0; i--) {
     if (targetString
     .regionMatches(length - i, suffix, 0, i)) {
     targetString += suffix.substring(i);
     break;
     if (i == 0) {
     // None of the suffix was present
     targetString += suffix;
     length = targetString.length();
     format.parse(targetString, parsePos);
     int endIndex = parsePos.getIndex();
     if (endIndex == length) {
     break; // Number is acceptable
     // Parse ended early
     // Since incomplete numbers don't always parse, try
     // to work out what went wrong.
     // First check for an incomplete positive prefix
     if (positivePrefixLen > 0 && endIndex < positivePrefixLen
     && length <= positivePrefixLen
     && targetString.regionMatches(0, positivePrefix, 0, length)) {
     break; // Accept for now
     // Next check for an incomplete negative prefix
     if (negativePrefixLen > 0 && endIndex < negativePrefixLen
     && length <= negativePrefixLen
     && targetString.regionMatches(0, negativePrefix, 0, length)) {
     break; // Accept for now
     // Allow a number that ends with the group
     // or decimal separator, if these are in use
     char lastChar = targetString.charAt(originalLength - 1);
     int decimalIndex = targetString.indexOf(decimalSeparator);
     if (format.isGroupingUsed() && lastChar == groupingSeparator
     && decimalIndex == -1) {
     // Allow a "," but only in integer part
     break;
     if (format.isParseIntegerOnly() == false
     && lastChar == decimalSeparator
     && decimalIndex == originalLength - 1) {
     // Allow a ".", but only one
     break;
     // No more corrections to make: must be an error
     if (errorListener != null) {
     errorListener.insertFailed(this, offset, str, a);
     return;
     } while (true == false);
     // Finally, add to the model
     super.insertString(offset, str, a);
     public void addInsertErrorListener(InsertErrorListener l) {
     if (errorListener == null) {
     errorListener = l;
     return;
     throw new IllegalArgumentException(
     "InsertErrorListener already registered");
     public void removeInsertErrorListener(InsertErrorListener l) {
     if (errorListener == l) {
     errorListener = null;
     public interface InsertErrorListener {
     public abstract void insertFailed(NumericPlainDocument doc, int offset,
     String str, AttributeSet a);
     protected InsertErrorListener errorListener;
     protected DecimalFormat format;
     protected char decimalSeparator;
     protected char groupingSeparator;
     protected String positivePrefix;
     protected String negativePrefix;
     protected int positivePrefixLen;
     protected int negativePrefixLen;
     protected String positiveSuffix;
     protected String negativeSuffix;
     protected int positiveSuffixLen;
     protected int negativeSuffixLen;
     protected ParsePosition parsePos = new ParsePosition(0);
     protected static DecimalFormat defaultFormat = new DecimalFormat();
this is not working as desired pls help me.
can we use this code and get the desired result or is there any other way to do this.
it is very urgent for me pls help immediately
thanks in advance

Answer 1

Hi camickr
i learned how to format the code now, and u also responded for my testarea problem , iam very much thankful to u, and now i repeat the same problem what i have with a text field.
actually i have window with a textfield on it and while end user starts entering data in it , it should be have as follows
when the user start typing numerics it should accept from right hand side and keep appending value from right hand side.
first the default value should be as 0.00 and as the user starts entering
then it is as follows
for ex
if i want to enter 123.45
user starts entering
1 then it should display as 0.01
2 then it should display as 0.12
3 then it should display as 1.23
4 then it should display as 12.34
5 then it should display as 123.45
i hope u will give me quick reply because this is very hard time for me.