JTextField accept only numbers and one dot

I found a solution for this problem:\nthis is the code i wrote\n\n\r\n\r\nchar c=evt.getKeyChar();\r\n if((Character.isDigit(c))||(c==KeyEvent.VK_PERIOD)||(c==KeyEvent.VK_BACK_SPACE)){\r\n int punto=0;\r\n if(c==KeyEvent.VK_PERIOD){ \r\n String s=pricefield.getText();\r\n int dot=s.indexOf('.');\r\n punto=dot;\r\n if(dot!=-1){\r\n getToolkit().beep();\r\n evt.consume();\r\n }\r\n }\r\n }\r\n else{ \r\n getToolkit().beep();\r\n evt.consume();\r\n }",

Don't use a KeyListener. That is old code when using AWT.\n\nSwing has newer and better API's.\n\nThe easiest way is to use a JFormattedTextField. Read the section from the Swing tutorial on How to Use Formatted Text Fields for more information and working examples.\n\nThe other option is so use a DocumentFilter. Read the section from the Swing tutorial on Implementing a DocumentFilter.",

private void textFieldKeyTyped(java.awt.event.KeyEvent evt) {\n\nGet the keyTyped and pass it to the method validate.\n\n if(!validate(evt.getKeyChar())){\n\n\nChar or keytyped is not a valid input, so let it consumed.\n\n evt.consume();\n }\n\n\nthis limit the input of Decimal, only ONE decimal point can be entered;\n\n if(evt.getKeyChar()==KeyEvent.VK_DECIMAL || evt.getKeyChar()==KeyEvent.VK_PERIOD){\n \n\n\nget the whole string entered in the textField;\n\n String field = textField.getText();\n\n\nget index of dot(. or decimal/period).\nindexOf() method returns -1 if String does not have any dot or decimal poits.\n\n int index = field.indexOf(".");\n\n\n if(!(index==-1)){ //index is not equal to -1\n evt.consume(); //consume\n }\n \n }\n } \n\n\nEvery keypress, this method gets called.\n\nprivate boolean validate(char ch){\n\n\nthis determine if the character has matching value to Integer, Decimal point, backspace or delete. It returns true if the char is a integer, decimal, delete or backspace, otherwise false.\nHowever it does not limit how many decimal points can be entered.\n\n if(!(Character.isDigit(ch)\n || ch==KeyEvent.VK_BACKSPACE \n || ch==KeyEvent.VK_DELETE \n || ch==KeyEvent.VK_DECIMAL\n || ch==KeyEvent.VK_PERIOD)){\n return false;\n }\n \n return true;\n } \n\n\nhere is the whole code, I have provided some comments, hope these will help.\n\nprivate void textFieldKeyTyped(java.awt.event.KeyEvent evt) { \n\n if(!validate(evt.getKeyChar())){ //get char or keytyped\n evt.consume();\n }\n //limit one dot or decimal point can be entered\n if(evt.getKeyChar()==KeyEvent.VK_DECIMAL || evt.getKeyChar()==KeyEvent.VK_PERIOD){\n \n String field = textField.getText(); //get the string in textField\n int index = field.indexOf("."); //find the index of dot(.) or decimal point\n if(!(index==-1)){ //if there is any\n evt.consume(); //consume the keytyped. this prevents the keytyped from appearing on the textfield;\n }\n \n }\n } \n //determine if keytyped is a valid input\n private boolean validate(char ch){\n \n if(!(Character.isDigit(ch)\n || ch==KeyEvent.VK_BACKSPACE \n || ch==KeyEvent.VK_DELETE \n || ch==KeyEvent.VK_DECIMAL \n || ch==KeyEvent.VK_PERIOD \n )){\n\n return false; //return false, because char is invalid \n }\n \n return true; // return true, when the if statement above does not meet its conditions \n } \n",