Chapter 16
The java.text Package

Format

Name

Format

Synopsis

Class Name:

java.text.Format

Superclass:

java.lang.Object

Immediate Subclasses:

java.text.DateFormat, java.text.MessageFormat,

java.text.NumberFormat

Interfaces Implemented:

java.lang.Cloneable, java.io.Serializable

Availability:

New as of JDK 1.1

The Format class is an abstract class that is the superclass of all classes that handle locale-sensitive parsing and formatting of dates, numbers, and messages. The two format() methods take the information in a supplied object and convert it to a string. The two parseObject() methods do the reverse; they take the information from a string and construct an appropriate object.

Class Summary

public abstract class java.text.Format extends java.lang.Object
                      implements java.io.Serializable, java.lang.Cloneable {
  // Instance Methods
  public Object clone();
  public final String format(Object obj);
  public abstract StringBuffer format(Object obj, StringBuffer toAppendTo, 
                               FieldPosition pos);
  public Object parseObject(String source);
  public abstract Object parseObject(String source, ParsePosition status);
}

Instance Methods

clone

public Object clone()

Returns

A copy of this Format.

Overrides

Object.clone()

Description

This method creates a copy of this Format and returns it.

format

public final String format(Object obj)

Parameters

obj: The object to be formatted.

Returns

A string that contains a formatted representation of the object.

Throws

IllegalArgumentException: If the given object cannot be formatted.

Description

This method formats the given object by calling format(Object, StringBuffer, FieldPosition) with an empty StringBuffer and a FieldPosition that has a value of 0.

 public abstract StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos)

Parameters

obj

The object to be formatted.

toAppendTo

A StringBuffer on which to append the formatted information.

pos

A field.

Returns

The given buffer toAppendTo with the formatted representation of the object appended to it.

Throws

IllegalArgumentException: If the given object cannot be formatted.

Description

This method formats the given object and appends the result to the given StringBuffer. After the object has been formatted, the beginning and ending indices of the given FieldPosition are updated to reflect the field's position in the formatted output.

A subclass of Format must implement this method.

parseObject

public Object parseObject(String source) throws ParseException

Parameters

source: The string to be parsed.

Returns

The object represented by the given string.

Throws

ParseException: If the text cannot be parsed by this Format.

Description

This method parses the given text and returns an appropriate object. It does this by calling parseObject(String, ParsePosition) with a ParsePosition that has an index of 0.

 public abstract Object parseObject(String source, ParsePosition status)

Parameters

source

The string to be parsed.

status

A ParsePosition object that specifies a position in the string.

Returns

The object represented by the text starting at the given position.

Description

This method parses the given text, starting at the specified position, and returns an object created from the data. After the string has been parsed, the given ParsePosition object is updated so that its index is after the parsed text.

A subclass of Format must implement this method.

Inherited Methods

Method	Inherited From	Method	Inherited From
`equals(Object)`	`Object`	`finalize()`	`Object`
`getClass()`	`Object`	`hashCode()`	`Object`
`notify()`	`Object`	`notifyAll()`	`Object`
`toString()`	`Object`	`wait()`	`Object`
`wait(long)`	`Object`	`wait(long, int)`	`Object`