程序包 java.text

类 FieldPosition

java.lang.Object

java.text.FieldPosition

public class FieldPosition
extends Object

FieldPosition is a simple class used by Format and its subclasses to identify fields in formatted output. Fields can be identified in two ways:

• By an integer constant, whose names typically end with _FIELD. The constants are defined in the various subclasses of Format.
• By a Format.Field constant, see ERA_FIELD and its friends in DateFormat for an example.

FieldPosition keeps track of the position of the field within the formatted output with two indices: the index of the first character of the field and the index of the last character of the field.

One version of the format method in the various Format classes requires a FieldPosition object as an argument. You use this format method to perform partial formatting or to get information about the formatted output (such as the position of a field).

If you are interested in the positions of all attributes in the formatted string use the Format method formatToCharacterIterator.

另请参阅:

Format

构造器概要

构造器

构造器	说明
FieldPosition(int field)	Creates a FieldPosition object for the given field.
FieldPosition(Format.Field attribute)	Creates a FieldPosition object for the given field constant.
FieldPosition(Format.Field attribute, int fieldID)	Creates a FieldPosition object for the given field.

方法概要

限定符和类型	方法	说明
boolean	equals(Object obj)	Overrides equals
int	getBeginIndex()	Retrieves the index of the first character in the requested field.
int	getEndIndex()	Retrieves the index of the character following the last character in the requested field.
int	getField()	Retrieves the field identifier.
Format.Field	getFieldAttribute()	Returns the field identifier as an attribute constant from one of the Field subclasses.
int	hashCode()	Returns a hash code for this FieldPosition.
void	setBeginIndex(int bi)	Sets the begin index.
void	setEndIndex(int ei)	Sets the end index.
String	toString()	Return a string representation of this FieldPosition.

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

构造器详细资料

FieldPosition

public FieldPosition(int field)

Creates a FieldPosition object for the given field. Fields are identified by constants, whose names typically end with _FIELD, in the various subclasses of Format.

参数:

field - the field identifier

另请参阅:

NumberFormat.INTEGER_FIELD, NumberFormat.FRACTION_FIELD, DateFormat.YEAR_FIELD, DateFormat.MONTH_FIELD

FieldPosition

public FieldPosition(Format.Field attribute)

Creates a FieldPosition object for the given field constant. Fields are identified by constants defined in the various Format subclasses. This is equivalent to calling new FieldPosition(attribute, -1).

参数:

attribute - Format.Field constant identifying a field

从以下版本开始:

1.4

FieldPosition

public FieldPosition(Format.Field attribute,
                     int fieldID)

Creates a FieldPosition object for the given field. The field is identified by an attribute constant from one of the Field subclasses as well as an integer field ID defined by the Format subclasses. Format subclasses that are aware of Field should give precedence to attribute and ignore fieldID if attribute is not null. However, older Format subclasses may not be aware of Field and rely on fieldID. If the field has no corresponding integer constant, fieldID should be -1.

参数:

attribute - Format.Field constant identifying a field

fieldID - integer constant identifying a field

从以下版本开始:

1.4

方法详细资料

getFieldAttribute

public Format.Field getFieldAttribute()

Returns the field identifier as an attribute constant from one of the Field subclasses. May return null if the field is specified only by an integer field ID.

返回:

Identifier for the field

从以下版本开始:

1.4

getField

public int getField()

Retrieves the field identifier.

返回:

the field identifier

getBeginIndex

public int getBeginIndex()

Retrieves the index of the first character in the requested field.

返回:

the begin index

getEndIndex

public int getEndIndex()

Retrieves the index of the character following the last character in the requested field.

返回:

the end index

setBeginIndex

public void setBeginIndex(int bi)

Sets the begin index. For use by subclasses of Format.

参数:

bi - the begin index

从以下版本开始:

1.2

setEndIndex

public void setEndIndex(int ei)

Sets the end index. For use by subclasses of Format.

参数:

ei - the end index

从以下版本开始:

1.2

equals

public boolean equals(Object obj)

Overrides equals

覆盖:

equals 在类中 Object

参数:

obj - the reference object with which to compare.

返回:

true if this object is the same as the obj argument; false otherwise.

另请参阅:

Object.hashCode(), HashMap

hashCode

public int hashCode()

Returns a hash code for this FieldPosition.

覆盖:

hashCode 在类中 Object

返回:

a hash code value for this object

另请参阅:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

toString

public String toString()

Return a string representation of this FieldPosition.

覆盖:

toString 在类中 Object

返回:

a string representation of this object