org.apache.commons.lang

Class BitField

public class BitField extends Object

Operations on bit-mapped fields.

Since: 2.0

Version: $Id: BitField.java 437554 2006-08-28 06:21:41Z bayard $

Author: Apache Jakarta POI Scott Sanders (sanders at apache dot org) Marc Johnson (mjohnson at apache dot org) Andrew C. Oliver (acoliver at apache dot org) Stephen Colebourne Pete Gieser Gary Gregory

Constructor Summary
BitField(int mask)

Creates a BitField instance.

Method Summary
intclear(int holder)

Clears the bits.

byteclearByte(byte holder)

Clears the bits.

shortclearShort(short holder)

Clears the bits.

intgetRawValue(int holder)

Obtains the value for the specified BitField, unshifted.

shortgetShortRawValue(short holder)

Obtains the value for the specified BitField, unshifted.

shortgetShortValue(short holder)

Obtains the value for the specified BitField, appropriately shifted right, as a short.

Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits).

intgetValue(int holder)

Obtains the value for the specified BitField, appropriately shifted right.

Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits).

booleanisAllSet(int holder)

Returns whether all of the bits are set or not.

This is a stricter test than BitField, in that all of the bits in a multi-bit set must be set for this method to return true.

booleanisSet(int holder)

Returns whether the field is set or not.

This is most commonly used for a single-bit field, which is often used to represent a boolean value; the results of using it for a multi-bit field is to determine whether *any* of its bits are set.

intset(int holder)

Sets the bits.

intsetBoolean(int holder, boolean flag)

Sets a boolean BitField.

bytesetByte(byte holder)

Sets the bits.

bytesetByteBoolean(byte holder, boolean flag)

Sets a boolean BitField.

shortsetShort(short holder)

Sets the bits.

shortsetShortBoolean(short holder, boolean flag)

Sets a boolean BitField.

shortsetShortValue(short holder, short value)

Replaces the bits with new values.

intsetValue(int holder, int value)

Replaces the bits with new values.

Constructor Detail

BitField

public BitField(int mask)

Creates a BitField instance.

Parameters: mask the mask specifying which bits apply to this BitField. Bits that are set in this mask are the bits that this BitField operates on

Method Detail

clear

public int clear(int holder)

Clears the bits.

Parameters: holder the int data containing the bits we're interested in

Returns: the value of holder with the specified bits cleared (set to 0)

clearByte

public byte clearByte(byte holder)

Clears the bits.

Parameters: holder the byte data containing the bits we're interested in

Returns: the value of holder with the specified bits cleared (set to 0)

clearShort

public short clearShort(short holder)

Clears the bits.

Parameters: holder the short data containing the bits we're interested in

Returns: the value of holder with the specified bits cleared (set to 0)

getRawValue

public int getRawValue(int holder)

Obtains the value for the specified BitField, unshifted.

Parameters: holder the int data containing the bits we're interested in

Returns: the selected bits

getShortRawValue

public short getShortRawValue(short holder)

Obtains the value for the specified BitField, unshifted.

Parameters: holder the short data containing the bits we're interested in

Returns: the selected bits

getShortValue

public short getShortValue(short holder)

Obtains the value for the specified BitField, appropriately shifted right, as a short.

Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits).

Parameters: holder the short data containing the bits we're interested in

Returns: the selected bits, shifted right appropriately

See Also: BitField

getValue

public int getValue(int holder)

Obtains the value for the specified BitField, appropriately shifted right.

Many users of a BitField will want to treat the specified bits as an int value, and will not want to be aware that the value is stored as a BitField (and so shifted left so many bits).

Parameters: holder the int data containing the bits we're interested in

Returns: the selected bits, shifted right appropriately

See Also: BitField

isAllSet

public boolean isAllSet(int holder)

Returns whether all of the bits are set or not.

This is a stricter test than BitField, in that all of the bits in a multi-bit set must be set for this method to return true.

Parameters: holder the int data containing the bits we're interested in

Returns: true if all of the bits are set, else false

isSet

public boolean isSet(int holder)

Returns whether the field is set or not.

This is most commonly used for a single-bit field, which is often used to represent a boolean value; the results of using it for a multi-bit field is to determine whether *any* of its bits are set.

Parameters: holder the int data containing the bits we're interested in

Returns: true if any of the bits are set, else false

set

public int set(int holder)

Sets the bits.

Parameters: holder the int data containing the bits we're interested in

Returns: the value of holder with the specified bits set to 1

setBoolean

public int setBoolean(int holder, boolean flag)

Sets a boolean BitField.

Parameters: holder the int data containing the bits we're interested in flag indicating whether to set or clear the bits

Returns: the value of holder with the specified bits set or cleared

setByte

public byte setByte(byte holder)

Sets the bits.

Parameters: holder the byte data containing the bits we're interested in

Returns: the value of holder with the specified bits set to 1

setByteBoolean

public byte setByteBoolean(byte holder, boolean flag)

Sets a boolean BitField.

Parameters: holder the byte data containing the bits we're interested in flag indicating whether to set or clear the bits

Returns: the value of holder with the specified bits set or cleared

setShort

public short setShort(short holder)

Sets the bits.

Parameters: holder the short data containing the bits we're interested in

Returns: the value of holder with the specified bits set to 1

setShortBoolean

public short setShortBoolean(short holder, boolean flag)

Sets a boolean BitField.

Parameters: holder the short data containing the bits we're interested in flag indicating whether to set or clear the bits

Returns: the value of holder with the specified bits set or cleared

setShortValue

public short setShortValue(short holder, short value)

Replaces the bits with new values.

Parameters: holder the short data containing the bits we're interested in value the new value for the specified bits

Returns: the value of holder with the bits from the value parameter replacing the old bits

See Also: BitField

setValue

public int setValue(int holder, int value)

Replaces the bits with new values.

Parameters: holder the int data containing the bits we're interested in value the new value for the specified bits

Returns: the value of holder with the bits from the value parameter replacing the old bits

See Also: BitField

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