Serializable
, Cloneable
public class MaskFormatter extends DefaultFormatter
MaskFormatter
is used to format and edit strings. The behavior of a MaskFormatter
is controlled by way of a String mask that specifies the valid characters that can be contained at a particular location in the Document
model. The following characters can be specified: Character | Description |
---|---|
# | Any valid number, uses Character.isDigit . |
' | Escape character, used to escape any of the special formatting characters. |
U | Any character (Character.isLetter ). All lowercase letters are mapped to upper case. |
L | Any character (Character.isLetter ). All upper case letters are mapped to lower case. |
A | Any character or number (Character.isLetter or Character.isDigit ). |
? | Any character (Character.isLetter ). |
* | Anything. |
H | Any hex character (0-9, a-f or A-F). |
Typically characters correspond to one char, but in certain languages this is not the case. The mask is on a per character basis, and will thus adjust to fit as many chars as are needed.
You can further restrict the characters that can be input by the setInvalidCharacters
and setValidCharacters
methods. setInvalidCharacters
allows you to specify which characters are not legal. setValidCharacters
allows you to specify which characters are valid. For example, the following code block is equivalent to a mask of '0xHHH' with no invalid/valid characters:
MaskFormatter formatter = new MaskFormatter("0x***"); formatter.setValidCharacters("0123456789abcdefABCDEF");
When initially formatting a value if the length of the string is less than the length of the mask, two things can happen. Either the placeholder string will be used, or the placeholder character will be used. Precedence is given to the placeholder string. For example:
MaskFormatter formatter = new MaskFormatter("###-####"); formatter.setPlaceholderCharacter('_'); System.out.println(formatter.valueToString("123"));
Would result in the string '123-____'. If setPlaceholder("555-1212")
was invoked '123-1212' would result. The placeholder String is only used on the initial format, on subsequent formats only the placeholder character will be used.
If a MaskFormatter
is configured to only allow valid characters (setAllowsInvalid(false)
) literal characters will be skipped as necessary when editing. Consider a MaskFormatter
with the mask "###-####" and current value "555-1212". Using the right arrow key to navigate through the field will result in (| indicates the position of the caret):
|555-1212 5|55-1212 55|5-1212 555-|1212 555-1|212The '-' is a literal (non-editable) character, and is skipped.
Similar behavior will result when editing. Consider inserting the string '123-45' and '12345' into the MaskFormatter
in the previous example. Both inserts will result in the same String, '123-45__'. When MaskFormatter
is processing the insert at character position 3 (the '-'), two things can happen:
By default MaskFormatter
will not allow invalid edits, you can change this with the setAllowsInvalid
method, and will commit edits on valid edits (use the setCommitsOnValidEdit
to change this).
By default, MaskFormatter
is in overwrite mode. That is as characters are typed a new character is not inserted, rather the character at the current location is replaced with the newly typed character. You can change this behavior by way of the method setOverwriteMode
.
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 JavaBeans has been added to the java.beans
package. Please see XMLEncoder
.
Constructor | Description |
---|---|
MaskFormatter() |
Creates a MaskFormatter with no mask. |
MaskFormatter |
Creates a MaskFormatter with the specified mask. |
Modifier and Type | Method | Description |
---|---|---|
String |
getInvalidCharacters() |
Returns the characters that are not valid for input. |
String |
getMask() |
Returns the formatting mask. |
String |
getPlaceholder() |
Returns the String to use if the value does not completely fill in the mask. |
char |
getPlaceholderCharacter() |
Returns the character to use in place of characters that are not present in the value, ie the user must fill them in. |
String |
getValidCharacters() |
Returns the valid characters that can be input. |
boolean |
getValueContainsLiteralCharacters() |
Returns true if stringToValue should return literal characters in the mask. |
void |
install |
Installs the DefaultFormatter onto a particular JFormattedTextField . |
void |
setInvalidCharacters |
Allows for further restricting of the characters that can be input. |
void |
setMask |
Sets the mask dictating the legal characters. |
void |
setPlaceholder |
Sets the string to use if the value does not completely fill in the mask. |
void |
setPlaceholderCharacter |
Sets the character to use in place of characters that are not present in the value, ie the user must fill them in. |
void |
setValidCharacters |
Allows for further restricting of the characters that can be input. |
void |
setValueContainsLiteralCharacters |
If true, the returned value and set value will also contain the literal characters in mask. |
Object |
stringToValue |
Parses the text, returning the appropriate Object representation of the String value . |
String |
valueToString |
Returns a String representation of the Object value based on the mask. |
clone, getAllowsInvalid, getCommitsOnValidEdit, getDocumentFilter, getNavigationFilter, getOverwriteMode, getValueClass, setAllowsInvalid, setCommitsOnValidEdit, setOverwriteMode, setValueClass
getActions, getFormattedTextField, invalidEdit, setEditValid, uninstall
public MaskFormatter()
public MaskFormatter(String mask) throws ParseException
MaskFormatter
with the specified mask. A ParseException
will be thrown if mask
is an invalid mask.mask
- the maskParseException
- if mask does not contain valid mask characterspublic void setMask(String mask) throws ParseException
ParseException
if mask
is not valid.mask
- the maskParseException
- if mask does not contain valid mask characterspublic String getMask()
public void setValidCharacters(String validCharacters)
invalidCharacters
, and in validCharacters
will be allowed to be input. Passing in null (the default) implies the valid characters are only bound by the mask and the invalid characters.validCharacters
- If non-null, specifies legal characters.public String getValidCharacters()
public void setInvalidCharacters(String invalidCharacters)
invalidCharacters
, and in validCharacters
will be allowed to be input. Passing in null (the default) implies the valid characters are only bound by the mask and the valid characters.invalidCharacters
- If non-null, specifies illegal characters.public String getInvalidCharacters()
public void setPlaceholder(String placeholder)
placeholder
- String used when formatting if the value does not completely fill the maskpublic String getPlaceholder()
public void setPlaceholderCharacter(char placeholder)
This is only applicable if the placeholder string has not been specified, or does not completely fill in the mask.
placeholder
- Character used when formatting if the value does not completely fill the maskpublic char getPlaceholderCharacter()
public void setValueContainsLiteralCharacters(boolean containsLiteralChars)
For example, if the mask is '(###) ###-####'
, the current value is '(415) 555-1212'
, and valueContainsLiteralCharacters
is true stringToValue
will return '(415) 555-1212'
. On the other hand, if valueContainsLiteralCharacters
is false, stringToValue
will return '4155551212'
.
containsLiteralChars
- Used to indicate if literal characters in mask should be returned in stringToValuepublic boolean getValueContainsLiteralCharacters()
stringToValue
should return literal characters in the mask.public Object stringToValue(String value) throws ParseException
value
. This strips the literal characters as necessary and invokes supers stringToValue
, so that if you have specified a value class (setValueClass
) an instance of it will be created. This will throw a ParseException
if the value does not match the current mask. Refer to setValueContainsLiteralCharacters(boolean)
for details on how literals are treated.stringToValue
in class DefaultFormatter
value
- String to convertParseException
- if there is an error in the conversionpublic String valueToString(Object value) throws ParseException
value
based on the mask. Refer to setValueContainsLiteralCharacters(boolean)
for details on how literals are treated.valueToString
in class DefaultFormatter
value
- Value to convertParseException
- if there is an error in the conversionpublic void install(JFormattedTextField ftf)
DefaultFormatter
onto a particular JFormattedTextField
. This will invoke valueToString
to convert the current value from the JFormattedTextField
to a String. This will then install the Action
s from getActions
, the DocumentFilter
returned from getDocumentFilter
and the NavigationFilter
returned from getNavigationFilter
onto the JFormattedTextField
. Subclasses will typically only need to override this if they wish to install additional listeners on the JFormattedTextField
.
If there is a ParseException
in converting the current value to a String, this will set the text to an empty String, and mark the JFormattedTextField
as being in an invalid state.
While this is a public method, this is typically only useful for subclassers of JFormattedTextField
. JFormattedTextField
will invoke this method at the appropriate times when the value changes, or its internal state changes.
install
in class DefaultFormatter
ftf
- JFormattedTextField to format for, may be null indicating uninstall from current JFormattedTextField.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/text/MaskFormatter.html