Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> iapi >> [ util overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.apache.derby.iapi.util
Class ByteArray  

java.lang.Object
  org.apache.derby.iapi.util.ByteArray

---

public final class ByteArray

extends java.lang.Object

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
private  byte[]	array
private  int	length
private  int	offset

 

Constructor Summary

ByteArray()

ByteArray(byte[] array)

ByteArray(byte[] array, int offset, int length)           Create an instance of this class that wraps ths given array.

 

Method Summary
private static boolean	equals(byte[] a, int aOffset, int aLength, byte[] b, int bOffset, int bLength)           Compare two byte arrays using value equality.
boolean	equals(java.lang.Object other)           Value equality for byte arrays.
byte[]	getArray()
int	getLength()
int	getOffset()
int	hashCode()           Get a value that represents this Object, as uniquely as possible within the confines of an int.
void	readExternal(java.io.ObjectInput in)           Read this object from a stream of stored objects.
void	setBytes(byte[] array)
void	setBytes(byte[] array, int length)
void	setBytes(byte[] array, int offset, int length)
void	setLength(int newLength)
void	writeExternal(java.io.ObjectOutput out)           Write the byte array out w/o compression

 

Methods inherited from class java.lang.Object

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

 

Field Detail

array

private byte[] array

---

offset

private int offset

---

length

private int length

Constructor Detail

ByteArray

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.

---

ByteArray

public ByteArray(byte[] array)

---

ByteArray

public ByteArray()

Method Detail

setBytes

public void setBytes(byte[] array)

---

setBytes

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

---

setBytes

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

---

equals

public boolean equals(java.lang.Object other)

Value equality for byte arrays.

---

hashCode

public int hashCode()

Description copied from class: java.lang.Object

Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

• Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
• It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in java.util.Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

---

getArray

public final byte[] getArray()

---

getOffset

public final int getOffset()

---

getLength

public final int getLength()

---

setLength

public final void setLength(int newLength)

---

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.io.IOException

Read this object from a stream of stored objects.

---

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Write the byte array out w/o compression

---

equals

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.

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> iapi >> [ util overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---