| java.lang.Object
 java.text.Format
All known Subclasses: java.text.MessageFormat, java.text.CharacterIteratorFieldDelegate, java.text.DateFormat, java.text.NumberFormat,
| Format | | abstract public class Format implements Serializable,Cloneable(Code) | | Format is an abstract base class for formatting locale-sensitive
information such as dates, messages, and numbers.
Format defines the programming interface for formatting
locale-sensitive objects into Strings (the
format method) and for parsing Strings back
into objects (the parseObject method).
Generally, a format's parseObject method must be able to parse
any string formatted by its format method. However, there may
be exceptional cases where this is not possible. For example, a
format method might create two adjacent integer numbers with
no separator in between, and in this case the parseObject could
not tell which digits belong to which number.
Subclassing
The Java 2 platform provides three specialized subclasses of Format--
DateFormat, MessageFormat, and
NumberFormat--for formatting dates, messages, and numbers,
respectively.
Concrete subclasses must implement three methods:
-
format(Object obj, StringBuffer toAppendTo, FieldPosition pos)
-
formatToCharacterIterator(Object obj)
-
parseObject(String source, ParsePosition pos)
These general methods allow polymorphic parsing and formatting of objects
and are used, for example, by MessageFormat.
Subclasses often also provide additional format methods for
specific input types as well as parse methods for specific
result types. Any parse method that does not take a
ParsePosition argument should throw ParseException
when no text in the required format is at the beginning of the input text.
Most subclasses will also implement the following factory methods:
-
getInstance for getting a useful format object appropriate
for the current locale
-
getInstance(Locale) for getting a useful format
object appropriate for the specified locale
In addition, some subclasses may also implement other
getXxxxInstance methods for more specialized control. For
example, the NumberFormat class provides
getPercentInstance and getCurrencyInstance
methods for getting specialized number formatters.
Subclasses of Format that allow programmers to create objects
for locales (with getInstance(Locale) for example)
must also implement the following class method:
public static Locale[] getAvailableLocales()
And finally subclasses may define a set of constants to identify the various
fields in the formatted output. These constants are used to create a FieldPosition
object which identifies what information is contained in the field and its
position in the formatted result. These constants should be named
item_FIELD where item identifies
the field. For examples of these constants, see ERA_FIELD and its
friends in
DateFormat .
Formats are generally not synchronized.
It is recommended to create separate format instances for each thread.
If multiple threads access a format concurrently, it must be synchronized
externally.
See Also: java.text.ParsePosition
See Also: java.text.FieldPosition
See Also: java.text.NumberFormat
See Also: java.text.DateFormat
See Also: java.text.MessageFormat
version:
1.28, 01/19/00
author:
Mark Davis |
| Inner Class :interface FieldDelegate | |
| Method Summary | |
| public Object | clone()
Creates and returns a copy of this object. | | AttributedCharacterIterator | createAttributedCharacterIterator(String s)
Creates an AttributedCharacterIterator for the String
s. | | AttributedCharacterIterator | createAttributedCharacterIterator(AttributedCharacterIterator[] iterators)
Creates an AttributedCharacterIterator containg the
concatenated contents of the passed in
AttributedCharacterIterators. | | AttributedCharacterIterator | createAttributedCharacterIterator(String string, AttributedCharacterIterator.Attribute key, Object value)
Returns an AttributedCharacterIterator with the String
string and additional key/value pair key,
value. | | AttributedCharacterIterator | createAttributedCharacterIterator(AttributedCharacterIterator iterator, AttributedCharacterIterator.Attribute key, Object value)
Creates an AttributedCharacterIterator with the contents of
iterator and the additional attribute key
value. | | final public String | format(Object obj)
Formats an object to produce a string. | | abstract public StringBuffer | format(Object obj, StringBuffer toAppendTo, FieldPosition pos)
Formats an object and appends the resulting text to a given string
buffer. | | public AttributedCharacterIterator | formatToCharacterIterator(Object obj)
Formats an Object producing an AttributedCharacterIterator.
You can use the returned AttributedCharacterIterator
to build the resulting String, as well as to determine information
about the resulting String.
Each attribute key of the AttributedCharacterIterator will be of type
Field. | | abstract public Object | parseObject(String source, ParsePosition pos)
Parses text from a string to produce an object.
The method attempts to parse text starting at the index given by
pos.
If parsing succeeds, then the index of pos is updated
to the index after the last character used (parsing does not necessarily
use all characters up to the end of the string), and the parsed
object is returned. | | public Object | parseObject(String source)
Parses text from the beginning of the given string to produce an object.
The method may not use the entire text of the given string.
Parameters:
source - A String whose beginning should be parsed. |
| clone | | public Object clone()(Code) | | Creates and returns a copy of this object.
a clone of this instance. |
| createAttributedCharacterIterator | | AttributedCharacterIterator createAttributedCharacterIterator(String s)(Code) | | Creates an AttributedCharacterIterator for the String
s.
Parameters:
s - String to create AttributedCharacterIterator from AttributedCharacterIterator wrapping s |
| createAttributedCharacterIterator | | AttributedCharacterIterator createAttributedCharacterIterator(AttributedCharacterIterator[] iterators)(Code) | | Creates an AttributedCharacterIterator containg the
concatenated contents of the passed in
AttributedCharacterIterators.
Parameters:
iterators - AttributedCharacterIterators used to create resultingAttributedCharacterIterators AttributedCharacterIterator wrapping passed inAttributedCharacterIterators |
| createAttributedCharacterIterator | | AttributedCharacterIterator createAttributedCharacterIterator(String string, AttributedCharacterIterator.Attribute key, Object value)(Code) | | Returns an AttributedCharacterIterator with the String
string and additional key/value pair key,
value.
Parameters:
string - String to create AttributedCharacterIterator from
Parameters:
key - Key for AttributedCharacterIterator
Parameters:
value - Value associated with key in AttributedCharacterIterator AttributedCharacterIterator wrapping args |
| createAttributedCharacterIterator | | AttributedCharacterIterator createAttributedCharacterIterator(AttributedCharacterIterator iterator, AttributedCharacterIterator.Attribute key, Object value)(Code) | | Creates an AttributedCharacterIterator with the contents of
iterator and the additional attribute key
value.
Parameters:
iterator - Initial AttributedCharacterIterator to add arg to
Parameters:
key - Key for AttributedCharacterIterator
Parameters:
value - Value associated with key in AttributedCharacterIterator AttributedCharacterIterator wrapping args |
| format | | abstract public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos)(Code) | | Formats an object and appends the resulting text to a given string
buffer.
If the pos argument identifies a field used by the format,
then its indices are set to the beginning and end of the first such
field encountered.
Parameters:
obj - The object to format
Parameters:
toAppendTo - where the text is to be appended
Parameters:
pos - A FieldPosition identifying a fieldin the formatted text the string buffer passed in as toAppendTo,with formatted text appended
exception:
NullPointerException - if toAppendTo orpos is null
exception:
IllegalArgumentException - if the Format cannot format the givenobject |
| formatToCharacterIterator | | public AttributedCharacterIterator formatToCharacterIterator(Object obj)(Code) | | Formats an Object producing an AttributedCharacterIterator.
You can use the returned AttributedCharacterIterator
to build the resulting String, as well as to determine information
about the resulting String.
Each attribute key of the AttributedCharacterIterator will be of type
Field. It is up to each Format implementation
to define what the legal values are for each attribute in the
AttributedCharacterIterator, but typically the attribute
key is also used as the attribute value.
The default implementation creates an
AttributedCharacterIterator with no attributes. Subclasses
that support fields should override this and create an
AttributedCharacterIterator with meaningful attributes.
exception:
NullPointerException - if obj is null.
exception:
IllegalArgumentException - when the Format cannot format thegiven object.
Parameters:
obj - The object to format AttributedCharacterIterator describing the formatted value.
since:
1.4 |
| parseObject | | abstract public Object parseObject(String source, ParsePosition pos)(Code) | | Parses text from a string to produce an object.
The method attempts to parse text starting at the index given by
pos.
If parsing succeeds, then the index of pos is updated
to the index after the last character used (parsing does not necessarily
use all characters up to the end of the string), and the parsed
object is returned. The updated pos can be used to
indicate the starting point for the next call to this method.
If an error occurs, then the index of pos is not
changed, the error index of pos is set to the index of
the character where the error occurred, and null is returned.
Parameters:
source - A String, part of which should be parsed.
Parameters:
pos - A ParsePosition object with index and errorindex information as described above. An Object parsed from the string. In case oferror, returns null.
exception:
NullPointerException - if pos is null. |
| parseObject | | public Object parseObject(String source) throws ParseException(Code) | | Parses text from the beginning of the given string to produce an object.
The method may not use the entire text of the given string.
Parameters:
source - A String whose beginning should be parsed. An Object parsed from the string.
exception:
ParseException - if the beginning of the specified stringcannot be parsed. |
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