Module java.base
Package java.text

Class 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.

    Since:
    1.1
    See Also:
    Format

    • Constructor Summary

      Constructors 
      Constructor Description
      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.

    • Constructor Detail

      • 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).
        Parameters:
        attribute - Format.Field constant identifying a field
        Since:
        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.
        Parameters:
        attribute - Format.Field constant identifying a field
        fieldID - integer constant identifying a field
        Since:
        1.4

    • Method Detail

      • 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.
        Returns:
        Identifier for the field
        Since:
        1.4

      • getField

        public int getField()
        Retrieves the field identifier.
        Returns:
        the field identifier

      • getBeginIndex

        public int getBeginIndex()
        Retrieves the index of the first character in the requested field.
        Returns:
        the begin index

      • getEndIndex

        public int getEndIndex()
        Retrieves the index of the character following the last character in the requested field.
        Returns:
        the end index

      • setBeginIndex

        public void setBeginIndex​(int bi)
        Sets the begin index. For use by subclasses of Format.
        Parameters:
        bi - the begin index
        Since:
        1.2

      • setEndIndex

        public void setEndIndex​(int ei)
        Sets the end index. For use by subclasses of Format.
        Parameters:
        ei - the end index
        Since:
        1.2

      • equals

        public boolean equals​(Object obj)
        Overrides equals
        Overrides:
        equals in class Object
        Parameters:
        obj - the reference object with which to compare.
        Returns:
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap

      • toString

        public String toString()
        Return a string representation of this FieldPosition.
        Overrides:
        toString in class Object
        Returns:
        a string representation of this object