Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Nested Classes](https://developer.android.com/reference/java/text/Format#nestedclasses) \| [Protected Ctors](https://developer.android.com/reference/java/text/Format#proctors) \| [Methods](https://developer.android.com/reference/java/text/Format#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/text/Format#inhmethods)
# Format
`
public
abstract
class
Format
`
`
extends https://developer.android.com/reference/java/lang/Object
`
`
implements
https://developer.android.com/reference/java/lang/Cloneable,
https://developer.android.com/reference/java/io/Serializable
`
|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.text.Format |
Known direct subclasses [DateFormat](https://developer.android.com/reference/java/text/DateFormat), [MessageFormat](https://developer.android.com/reference/java/text/MessageFormat), [NumberFormat](https://developer.android.com/reference/java/text/NumberFormat), [SelectFormat](https://developer.android.com/reference/android/icu/text/SelectFormat), [UFormat](https://developer.android.com/reference/android/icu/text/UFormat) [DateFormat](https://developer.android.com/reference/java/text/DateFormat) `DateFormat` is an abstract class for date/time formatting subclasses which formats and parses dates or time in a language-independent manner. [MessageFormat](https://developer.android.com/reference/java/text/MessageFormat) `MessageFormat` provides a means to produce concatenated messages in a language-neutral way. [NumberFormat](https://developer.android.com/reference/java/text/NumberFormat) `NumberFormat` is the abstract base class for all number formats. [SelectFormat](https://developer.android.com/reference/android/icu/text/SelectFormat) `SelectFormat` supports the creation of internationalized
messages by selecting phrases based on keywords.
[UFormat](https://developer.android.com/reference/android/icu/text/UFormat) An abstract class that extends `https://developer.android.com/reference/java/text/Format` to provide additional ICU protocol, specifically, the `getLocale()` API. Known indirect subclasses [ChoiceFormat](https://developer.android.com/reference/java/text/ChoiceFormat), [CompactDecimalFormat](https://developer.android.com/reference/android/icu/text/CompactDecimalFormat), [DateFormat](https://developer.android.com/reference/android/icu/text/DateFormat), [DateIntervalFormat](https://developer.android.com/reference/android/icu/text/DateIntervalFormat), [DecimalFormat](https://developer.android.com/reference/android/icu/text/DecimalFormat), [MeasureFormat](https://developer.android.com/reference/android/icu/text/MeasureFormat), [MessageFormat](https://developer.android.com/reference/android/icu/text/MessageFormat), [NumberFormat](https://developer.android.com/reference/android/icu/text/NumberFormat), [PluralFormat](https://developer.android.com/reference/android/icu/text/PluralFormat), [SimpleDateFormat](https://developer.android.com/reference/android/icu/text/SimpleDateFormat), [TimeZoneFormat](https://developer.android.com/reference/android/icu/text/TimeZoneFormat) [ChoiceFormat](https://developer.android.com/reference/java/text/ChoiceFormat) A `ChoiceFormat` allows you to attach a format to a range of numbers. [CompactDecimalFormat](https://developer.android.com/reference/android/icu/text/CompactDecimalFormat) Formats numbers in compact (abbreviated) notation, like "1.2K" instead of "1200". [DateFormat](https://developer.android.com/reference/android/icu/text/DateFormat) **\[icu enhancement\]** ICU's replacement for `https://developer.android.com/reference/java/text/DateFormat`. Methods, fields, and other functionality specific to ICU are labeled '**\[icu\]**'. [DateIntervalFormat](https://developer.android.com/reference/android/icu/text/DateIntervalFormat) DateIntervalFormat is a class for formatting and parsing date intervals in a language-independent manner. [DecimalFormat](https://developer.android.com/reference/android/icu/text/DecimalFormat) **\[icu enhancement\]** ICU's replacement for `https://developer.android.com/reference/java/text/DecimalFormat`. Methods, fields, and other functionality specific to ICU are labeled '**\[icu\]**'. [MeasureFormat](https://developer.android.com/reference/android/icu/text/MeasureFormat) A formatter for Measure objects. [MessageFormat](https://developer.android.com/reference/android/icu/text/MessageFormat) **\[icu enhancement\]** ICU's replacement for `https://developer.android.com/reference/java/text/MessageFormat`. Methods, fields, and other functionality specific to ICU are labeled '**\[icu\]**'. [NumberFormat](https://developer.android.com/reference/android/icu/text/NumberFormat) **\[icu enhancement\]** ICU's replacement for `https://developer.android.com/reference/java/text/NumberFormat`. Methods, fields, and other functionality specific to ICU are labeled '**\[icu\]**'. [PluralFormat](https://developer.android.com/reference/android/icu/text/PluralFormat) `PluralFormat` supports the creation of internationalized messages with plural inflection. [SimpleDateFormat](https://developer.android.com/reference/android/icu/text/SimpleDateFormat) **\[icu enhancement\]** ICU's replacement for `https://developer.android.com/reference/java/text/SimpleDateFormat`. Methods, fields, and other functionality specific to ICU are labeled '**\[icu\]**'. [TimeZoneFormat](https://developer.android.com/reference/android/icu/text/TimeZoneFormat) `TimeZoneFormat` supports time zone display name formatting and parsing.
*** ** * ** ***
`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 `String`s (the
`format` method) and for parsing `String`s 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 Platform provides three specialized subclasses of `Format`--
`DateFormat`, `MessageFormat`, and
`NumberFormat`--for formatting dates, messages, and numbers,
respectively.
Concrete subclasses must implement three methods:
1. `format(Object obj, StringBuffer toAppendTo, FieldPosition pos)`
2. `formatToCharacterIterator(Object obj)`
3. `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:
1. `getInstance` for getting a useful format object appropriate for the current locale
2. `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 `https://developer.android.com/reference/java/text/DateFormat`.
### Synchronization
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:**
- `https://developer.android.com/reference/java/text/ParsePosition`
- `https://developer.android.com/reference/java/text/FieldPosition`
- `https://developer.android.com/reference/java/text/NumberFormat`
- `https://developer.android.com/reference/java/text/DateFormat`
- `https://developer.android.com/reference/java/text/MessageFormat`
## Summary
| ### Nested classes ||
|---|---|
| ` class` | `https://developer.android.com/reference/java/text/Format.Field` Defines constants that are used as attribute keys in the `AttributedCharacterIterator` returned from `Format.formatToCharacterIterator` and as field identifiers in `FieldPosition`. |
| ### Protected constructors ||
|---|---|
| ` https://developer.android.com/reference/java/text/Format#Format()() ` Sole constructor. |
| ### Public methods ||
|---|---|
| ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/text/Format#clone()() ` Creates and returns a copy of this object. |
| ` final https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/text/Format#format(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Formats an object to produce a string. |
| ` abstract https://developer.android.com/reference/java/lang/StringBuffer` | ` https://developer.android.com/reference/java/text/Format#format(java.lang.Object,%20java.lang.StringBuffer,%20java.text.FieldPosition)(https://developer.android.com/reference/java/lang/Object obj, https://developer.android.com/reference/java/lang/StringBuffer toAppendTo, https://developer.android.com/reference/java/text/FieldPosition pos) ` Formats an object and appends the resulting text to a given string buffer. |
| ` https://developer.android.com/reference/java/text/AttributedCharacterIterator` | ` https://developer.android.com/reference/java/text/Format#formatToCharacterIterator(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Formats an Object producing an `AttributedCharacterIterator`. |
| ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/text/Format#parseObject(java.lang.String)(https://developer.android.com/reference/java/lang/String source) ` Parses text from the beginning of the given string to produce an object. |
| ` abstract https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/text/Format#parseObject(java.lang.String,%20java.text.ParsePosition)(https://developer.android.com/reference/java/lang/String source, https://developer.android.com/reference/java/text/ParsePosition pos) ` Parses text from a string to produce an object. |
### Inherited methods
From class `
https://developer.android.com/reference/java/lang/Object
` `
https://developer.android.com/reference/java/lang/Object` `
https://developer.android.com/reference/java/lang/Object#clone()()
`
Creates and returns a copy of this object.
`
boolean` `
https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj)
`
Indicates whether some other object is "equal to" this one.
`
void` `
https://developer.android.com/reference/java/lang/Object#finalize()()
`
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
`
final
https://developer.android.com/reference/java/lang/Class` `
https://developer.android.com/reference/java/lang/Object#getClass()()
`
Returns the runtime class of this `Object`.
`
int` `
https://developer.android.com/reference/java/lang/Object#hashCode()()
`
Returns a hash code value for the object.
`
final
void` `
https://developer.android.com/reference/java/lang/Object#notify()()
`
Wakes up a single thread that is waiting on this object's
monitor.
`
final
void` `
https://developer.android.com/reference/java/lang/Object#notifyAll()()
`
Wakes up all threads that are waiting on this object's monitor.
`
https://developer.android.com/reference/java/lang/String` `
https://developer.android.com/reference/java/lang/Object#toString()()
`
Returns a string representation of the object.
`
final
void` `
https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos)
`
Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.
`
final
void` `
https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis)
`
Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*, or until a
certain amount of real time has elapsed.
`
final
void` `
https://developer.android.com/reference/java/lang/Object#wait()()
`
Causes the current thread to wait until it is awakened, typically
by being *notified* or *interrupted*.
## Protected constructors
### Format
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected Format ()
```
Sole constructor. (For invocation by subclass constructors, typically
implicit.)
## Public methods
### clone
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public Object clone ()
```
Creates and returns a copy of this object.
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/Object` | a clone of this instance.
|
### format
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public final String format (Object obj)
```
Formats an object to produce a string. This is equivalent to
> `https://developer.android.com/reference/java/text/Format#format(java.lang.Object,%20java.lang.StringBuffer,%20java.text.FieldPosition)``(obj,
> new StringBuffer(), new FieldPosition(0)).toString();`
| Parameters ||
|---|---|
| `obj` | `Object`: The object to format
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/String` | Formatted string.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/IllegalArgumentException` | if the Format cannot format the given object |
### format
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public abstract StringBuffer format (Object obj,
StringBuffer toAppendTo,
FieldPosition pos)
```
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` | `Object`: The object to format
|
| `toAppendTo` | `StringBuffer`: where the text is to be appended
|
| `pos` | `FieldPosition`: A `FieldPosition` identifying a field in the formatted text
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/StringBuffer` | the string buffer passed in as `toAppendTo`, with formatted text appended
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/IllegalArgumentException` | if the Format cannot format the given object |
| `https://developer.android.com/reference/java/lang/NullPointerException` | if `toAppendTo` or `pos` is null |
### formatToCharacterIterator
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
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`. 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.
| Parameters ||
|---|---|
| `obj` | `Object`: The object to format
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/text/AttributedCharacterIterator` | AttributedCharacterIterator describing the formatted value.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/IllegalArgumentException` | when the Format cannot format the given object. |
| `https://developer.android.com/reference/java/lang/NullPointerException` | if obj is null. |
### parseObject
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
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` | `String`: A `String` whose beginning should be parsed.
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/Object` | An `Object` parsed from the string.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/NullPointerException` | if `source` is null. |
| `https://developer.android.com/reference/java/text/ParseException` | if the beginning of the specified string cannot be parsed. |
### parseObject
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public abstract 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. 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` | `String`: A `String`, part of which should be parsed.
|
| `pos` | `ParsePosition`: A `ParsePosition` object with index and error index information as described above.
|
| Returns ||
|---|---|
| `https://developer.android.com/reference/java/lang/Object` | An `Object` parsed from the string. In case of error, returns null.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/NullPointerException` | if `source` or `pos` is null. |