Top Description Fields Constructors Methods
org.apache.derby.iapi.util

public final Class ByteArray

extends Object
Class Inheritance
Imports
java.io.ObjectOutput, .ObjectInput, .IOException
ByteArray wraps java byte arrays (byte[]) to allow byte arrays to be used as keys in hashtables. This is required because the equals function on byte[] directly uses reference equality.

This class also allows the trio of array, offset and length to be carried around as a single object.

Field Summary

Modifier and TypeField and Description
private byte[]
array

private int
length

private int
offset

Constructor Summary

AccessConstructor and Description
public
ByteArray(byte[] array, int offset, int length)

Create an instance of this class that wraps ths given array.

public
ByteArray(byte[] array)

public
ByteArray()

Method Summary

Modifier and TypeMethod and Description
public boolean
equals(Object
the reference object with which to compare.
other)

Overrides java.lang.Object.equals.

Value equality for byte arrays.

private static boolean
equals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength)

Compare two byte arrays using value equality.

public final byte[]
getArray()

public final int
getLength()

public final int
getOffset()

public int
hashCode()

Overrides java.lang.Object.hashCode.

Returns a hash code value for this object.

public void
readExternal(ObjectInput
read this.
in)

Read this object from a stream of stored objects.

public void
setBytes(byte[] array)

public void
setBytes(byte[] array, int length)

public void
setBytes(byte[] array, int offset, int length)

public final void
setLength(int newLength)

public void
writeExternal(ObjectOutput
write bytes here.
out)

Write the byte array out w/o compression

Inherited from java.lang.Object:
clonefinalizegetClassnotifynotifyAlltoStringwaitwaitwait

Field Detail

arrayback to summary
private byte[] array
lengthback to summary
private int length
offsetback to summary
private int offset

Constructor Detail

ByteArrayback to summary
public ByteArray(byte[] array, int offset, int length)

Create an instance of this class that wraps ths given array. This class does not make a copy of the array, it just saves the reference.

ByteArrayback to summary
public ByteArray(byte[] array)
ByteArrayback to summary
public ByteArray()

Method Detail

equalsback to summary
public boolean equals(Object other)

Overrides java.lang.Object.equals.

Value equality for byte arrays.

Parameters
other:Object

Doc from java.lang.Object.equals.

the reference object with which to compare.

Returns:boolean

Doc from java.lang.Object.equals.

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

equalsback to summary
private static boolean equals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength)

Compare two byte arrays using value equality. Two byte arrays are equal if their length is identical and their contents are identical.

getArrayback to summary
public final byte[] getArray()
getLengthback to summary
public final int getLength()
getOffsetback to summary
public final int getOffset()
hashCodeback to summary
public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for this object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
Returns:int

a hash code value for this object

readExternalback to summary
public void readExternal(ObjectInput in) throws IOException

Read this object from a stream of stored objects.

Parameters
in:ObjectInput

read this.

Exceptions
IOException:
thrown on error
setBytesback to summary
public void setBytes(byte[] array)
setBytesback to summary
public void setBytes(byte[] array, int length)
setBytesback to summary
public void setBytes(byte[] array, int offset, int length)
setLengthback to summary
public final void setLength(int newLength)
writeExternalback to summary
public void writeExternal(ObjectOutput out) throws IOException

Write the byte array out w/o compression

Parameters
out:ObjectOutput

write bytes here.

Exceptions
IOException:
thrown on error