Java™ Platform
Standard Ed. 6

Class NumberFormatter

  extended by javax.swing.JFormattedTextField.AbstractFormatter
      extended by javax.swing.text.DefaultFormatter
          extended by javax.swing.text.InternationalFormatter
              extended by javax.swing.text.NumberFormatter
All Implemented Interfaces:
Serializable, Cloneable

public class NumberFormatter
extends InternationalFormatter

NumberFormatter subclasses InternationalFormatter adding special behavior for numbers. Among the specializations are (these are only used if the NumberFormatter does not display invalid nubers, eg setAllowsInvalid(false)):

If you are displaying scientific numbers, you may wish to turn on overwrite mode, setOverwriteMode(true). For example:

 DecimalFormat decimalFormat = new DecimalFormat("0.000E0");
 NumberFormatter textFormatter = new NumberFormatter(decimalFormat);

If you are going to allow the user to enter decimal values, you should either force the DecimalFormat to contain at least one decimal (#.0###), or allow the value to be invalid setAllowsInvalid(true). Otherwise users may not be able to input decimal values.

NumberFormatter provides slightly different behavior to stringToValue than that of its superclass. If you have specified a Class for values, DefaultFormatter.setValueClass(java.lang.Class), that is one of of Integer, Long, Float, Double, Byte or Short and the Format's parseObject returns an instance of Number, the corresponding instance of the value class will be created using the constructor appropriate for the primitive type the value class represents. For example: setValueClass(Integer.class) will cause the resulting value to be created via new Integer(((Number)formatter.parseObject(string)).intValue()). This is typically useful if you wish to set a min/max value as the various Number implementations are generally not comparable to each other. This is also useful if for some reason you need a specific Number implementation for your values.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeansTM has been added to the java.beans package. Please see XMLEncoder.


Constructor Summary
          Creates a NumberFormatter with the a default NumberFormat instance obtained from NumberFormat.getNumberInstance().
NumberFormatter(NumberFormat format)
          Creates a NumberFormatter with the specified Format instance.
Method Summary
 void setFormat(Format format)
          Sets the format that dictates the legal values that can be edited and displayed.
Methods inherited from class javax.swing.text.InternationalFormatter
clone, getActions, getFields, getFormat, getMaximum, getMinimum, install, setMaximum, setMinimum, stringToValue, valueToString
Methods inherited from class javax.swing.text.DefaultFormatter
getAllowsInvalid, getCommitsOnValidEdit, getDocumentFilter, getNavigationFilter, getOverwriteMode, getValueClass, setAllowsInvalid, setCommitsOnValidEdit, setOverwriteMode, setValueClass
Methods inherited from class javax.swing.JFormattedTextField.AbstractFormatter
getFormattedTextField, invalidEdit, setEditValid, uninstall
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail


public NumberFormatter()
Creates a NumberFormatter with the a default NumberFormat instance obtained from NumberFormat.getNumberInstance().


public NumberFormatter(NumberFormat format)
Creates a NumberFormatter with the specified Format instance.

format - Format used to dictate legal values
Method Detail


public void setFormat(Format format)
Sets the format that dictates the legal values that can be edited and displayed.

If you have used the nullary constructor the value of this property will be determined for the current locale by way of the NumberFormat.getNumberInstance() method.

setFormat in class InternationalFormatter
format - NumberFormat instance used to dictate legal values

Java™ Platform
Standard Ed. 6

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