org.w3c.cci2.ByteString Maven / Gradle / Ivy
/*
* ====================================================================
* Project: openMDX, http://www.openmdx.org/
* Description: ByteString
* Owner: OMEX AG, Switzerland, http://www.omex.ch
* ====================================================================
*
* This software is published under the BSD license as listed below.
*
* Copyright (c) 2008-2009, OMEX AG, Switzerland
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* * Neither the name of the openMDX team nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ------------------
*
* This product includes software developed by other organizations as
* listed in the NOTICE file.
*/
package org.w3c.cci2;
import java.util.Arrays;
/**
* Byte String
*/
public final class ByteString implements Final {
/**
* Constructor
*
* @param buffer a reference to the buffer is kept by
* ByteString.
*
* Note:
* The buffer must not be modified by a cooperative
* program after it has been used as ByteString
* constructor argument.
*
*/
public ByteString(
byte[] buffer
){
this(buffer, 0, buffer.length);
}
/**
* Constructor
*
* @param buffer a reference to the buffer is kept by
* ByteString.
*
* Note:
* The buffer must not be modified by a cooperative
* program after it has been used as ByteString
* constructor argument.
*
* @param offset the buffer's content before offset
* is ignored
* @param length the buffer's content after offset + length
* is ignored
*/
public ByteString(
byte[] buffer,
int offset,
int length
){
this.buffer = buffer;
this.offset = offset;
this.length = length;
}
/**
* Retrieve the buffer.
*
* Note:
* You must never modify this buffer!
*
* @return Returns the bytes.
*/
public final byte[] buffer() {
return this.buffer;
}
/**
* Retrieve offset.
*
* @return Returns the offset.
*/
public final int offset() {
return this.offset;
}
/* (non-Javadoc)
* @see java.lang.CharSequence#length()
*/
public int length() {
return this.length;
}
/* (non-Javadoc)
* @see java.lang.CharSequence#subSequence(int, int)
*/
public ByteString subSequence(int start, int end) {
int length = end - start;
if(start < 0 || end < 0 || length < 0 || end > length()) {
throw new IndexOutOfBoundsException(
"[" + start + "," + end + "] doos not fit into [0," + this.length + "]"
);
}
return new ByteString(
this.buffer,
this.offset + start,
length
);
}
/**
* Creates a newly allocated byte array.
* Its size is the length of this byte string.
*
* @return the contents of this byte string, as a byte array.
* @see org.w3c.cci2.ByteString#length()
*/
public byte[] toArray() {
byte[] buffer = new byte[this.length];
System.arraycopy(this.buffer, this.offset, buffer, 0, this.length);
return buffer;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
if(this.string == null) {
this.string = String.valueOf(
toHexadecimalString(this.buffer, this.offset, this.length * 2)
);
}
return this.string;
}
/**
* "Normalize" the array
*
* @return the original array or a copy of a sub-sequence
*/
private byte[] asArray(){
if(this.array == null) {
this.array = this.offset == 0 && this.length == this.buffer.length ? this.buffer : this.toArray();
}
return this.array;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if(obj instanceof ByteString) {
ByteString that = (ByteString) obj;
return Arrays.equals(this.asArray(), that.asArray());
} else {
return false;
}
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return Arrays.hashCode(asArray());
}
/**
* Convert the bytes value to a hexadecimal string
*
* @param value to be formatted
* @param offset the offset in the buffer of the first byte to format.
* @param digits number of digits, maybe leading to trailing 0s
*
* @return the bytes value as hexadecimal string
*/
private static char[] toHexadecimalString(
byte[] value,
int offset,
int digits
){
char[] buffer = new char[digits];
int available = 2 * (value.length - offset);
int cursor = 0;
int end = digits;
if(available < digits) end = available;
if(offset < 0) cursor = -2 * offset;
if (cursor != 0 || end != digits) Arrays.fill(buffer, ' ');
while(cursor < end) {
byte b = value[offset + cursor / 2];
if(cursor % 2 == 0) b >>=4;
buffer[cursor++] = HEXADECIMAL_DIGITS[b & 0xf];
}
return buffer;
}
//-----------------------------------------------------------------------
// Members
//-----------------------------------------------------------------------
private static final long serialVersionUID = 3826766941878437515L;
private final static char[] HEXADECIMAL_DIGITS = new char[]{
'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
};
/**
* @serial the buffer
*/
private final byte[] buffer;
/**
* @serial the offset
*/
private final int offset;
/**
* @serial the length
*/
private final int length;
/**
* This byte string's String representation.
*/
private transient String string;
/**
* This byte string's array representation.
*/
private transient byte[] array;
}