org.zkoss.lang
Class Objects

java.lang.Object
  org.zkoss.lang.Objects

public class Objects
extends Object

Utilities related to the Object class.

Author:

tomyeh

Field Summary

static String	BAR0_STRING Deprecated. As of release 6.0.0, not worth to have this API.
static String	BAR1_STRING Deprecated. As of release 6.0.0, not worth to have this API.
static String	BAR2_STRING Deprecated. As of release 6.0.0, not worth to have this API.
static Character	NULL_CHARACTER The null character.
static char	PATH_SEPARATOR_CHAR Deprecated. As of release 6.0.0, never used and confusing.
static String	PATH_SEPARATOR_STRING Deprecated. As of release 6.0.0, never used and confusing.
static Object	UNKNOWN Denotes unknown.
static BigDecimal	ZERO_BIG_DECIMAL Represents 0 in big decimal.
static BigInteger	ZERO_BIG_INTEGER Represents 0 in big integer.
static Byte	ZERO_BYTE The zero integer.
static Double	ZERO_DOUBLE The zero double.
static Float	ZERO_FLOAT The zero float.
static Integer	ZERO_INTEGER The zero integer.
static Long	ZERO_LONG The zero long.
static Short	ZERO_SHORT The zero short.

Constructor Summary

Objects()

Method Summary

static Object	clone(Object o) Clones the specified object.
static boolean	equals(Object a, Object b) Tests whether two objects are equals.
static int	hashCode(boolean[] v) Generates hash codes for an array of boolean.
static int	hashCode(byte[] v) Generates hash codes for an array of bytes.
static int	hashCode(byte[] v, int len) Generates hash codes for an array of bytes up to the specified length.
static int	hashCode(char[] v) Generates hash codes for an array.
static int	hashCode(int[] v) Generates hash codes for an array.
static int	hashCode(long[] v) Generates hash codes for an array.
static int	hashCode(Object o) Returns the object's hash code, or zero if null.
static int	hashCode(short[] v) Generates hash codes for an array.
static int	nextHashCode(int prevHashVal, int newVal) Returns the next hash value by giving the previous one and a new one.
static byte[]	toByteArray(byte v) Converts a byte to a big-endian byte array.
static byte[]	toByteArray(int v) Converts an integer to a big-endian byte array.
static byte[]	toByteArray(long v) Converts a long to a big-endian byte array.
static byte[]	toByteArray(short v) Converts a short to a big-endian byte array.
static char[]	toCharArray(Object o) Converts any object to a character array.
static String	toString(Object o) Converts any object to a string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

UNKNOWN

public static final Object UNKNOWN

Denotes unknown. It is useful if both null and unknown is required.

ZERO_LONG

public static final Long ZERO_LONG

The zero long.

ZERO_INTEGER

public static final Integer ZERO_INTEGER

The zero integer.

ZERO_SHORT

public static final Short ZERO_SHORT

The zero short.

ZERO_BYTE

public static final Byte ZERO_BYTE

The zero integer.

ZERO_FLOAT

public static final Float ZERO_FLOAT

The zero float.

ZERO_DOUBLE

public static final Double ZERO_DOUBLE

The zero double.

ZERO_BIG_DECIMAL

public static final BigDecimal ZERO_BIG_DECIMAL

Represents 0 in big decimal. The same as BigDecimals.ZERO.

See Also:

BigDecimals.ONE

ZERO_BIG_INTEGER

public static final BigInteger ZERO_BIG_INTEGER

Represents 0 in big integer. Same as BigIntegers.ZERO.

NULL_CHARACTER

public static final Character NULL_CHARACTER

The null character.

PATH_SEPARATOR_CHAR

public static final char PATH_SEPARATOR_CHAR

Deprecated. As of release 6.0.0, never used and confusing.

See Also:

Constant Field Values

PATH_SEPARATOR_STRING

public static final String PATH_SEPARATOR_STRING

Deprecated. As of release 6.0.0, never used and confusing.

See Also:

Constant Field Values

BAR0_STRING

public static final String BAR0_STRING

Deprecated. As of release 6.0.0, not worth to have this API.

See Also:

Constant Field Values

BAR1_STRING

public static final String BAR1_STRING

Deprecated. As of release 6.0.0, not worth to have this API.

See Also:

Constant Field Values

BAR2_STRING

public static final String BAR2_STRING

Deprecated. As of release 6.0.0, not worth to have this API.

See Also:

Constant Field Values

Constructor Detail

Objects

public Objects()

Method Detail

nextHashCode

public static final int nextHashCode(int prevHashVal,
                                     int newVal)

Returns the next hash value by giving the previous one and a new one. The caller usually uses a loop to accumulate all related fields.

Parameters:

prevHashVal - the previous hash value returned by this method; 0 if it is the first call.

newVal - the new value to put in

Returns:

the new hash value

hashCode

public static final int hashCode(boolean[] v)

Generates hash codes for an array of boolean. It is suggested to cache the hash code.

Parameters:

v - the array

Returns:

the hash code

hashCode

public static final int hashCode(byte[] v)

Generates hash codes for an array of bytes. It is suggested to cache the hash code.

Parameters:

v - the array

Returns:

the hash code

hashCode

public static final int hashCode(byte[] v,
                                 int len)

Generates hash codes for an array of bytes up to the specified length. It is suggested to cache the hash code.

Parameters:

v - the array

len - the maximal length to generate hashCode

Returns:

the hash code

hashCode

public static final int hashCode(char[] v)

Generates hash codes for an array. It is suggested to cache the hash code.

Parameters:

v - the array

Returns:

the hash code

hashCode

public static final int hashCode(short[] v)

Generates hash codes for an array. It is suggested to cache the hash code.

Parameters:

v - the array

Returns:

the hash code

hashCode

public static final int hashCode(int[] v)

Generates hash codes for an array. It is suggested to cache the hash code.

Parameters:

v - the byte array

Returns:

the hash code

hashCode

public static final int hashCode(long[] v)

Generates hash codes for an array. It is suggested to cache the hash code.

Parameters:

v - the array

Returns:

the hash code

hashCode

public static final int hashCode(Object o)

Returns the object's hash code, or zero if null.

equals

public static final boolean equals(Object a,
                                   Object b)

Tests whether two objects are equals.

It takes care of the null case. Thus, it is helpful to implement Object.equals.

Notice: it uses compareTo if BigDecimal is found. So, in this case, a.equals(b) might not be the same as Objects.equals(a, b).

If both a and b are Object[], they are compared item-by-item.

toCharArray

public static final char[] toCharArray(Object o)

Converts any object to a character array.

Parameters:

o - the object to convert

Returns:

the char array or null if o is null

toString

public static final String toString(Object o)

Converts any object to a string. If o is an object array, it invokes ArraysX.toString(java.lang.Object[]) to make the string more readable.

toByteArray

public static final byte[] toByteArray(int v)

Converts an integer to a big-endian byte array.

toByteArray

public static final byte[] toByteArray(long v)

Converts a long to a big-endian byte array.

toByteArray

public static final byte[] toByteArray(short v)

Converts a short to a big-endian byte array.

toByteArray

public static final byte[] toByteArray(byte v)

Converts a byte to a big-endian byte array.

clone

public static final Object clone(Object o)

Clones the specified object. Use clone() if Cloneable. Otherwise, try to serialize/deserialize it by use of MarshalledObject.

If o is null, null is returned.

Throws:

SystemException - if failed to clone