Conversion utilities : Data Type cast « Data Type « Java
Conversion utilities
/*
* Copyright (c) 2002,2003 Free Software Foundation
* developed under the custody of the
* Open Web Application Security Project
* (http://www.owasp.org)
*
* This file is part of the OWASP common library (OCL).
* OCL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* OCL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* The valid license text for this file can be retrieved with
* the call: java -cp owasp.jar org.owasp.LICENSE
*
* If you are not able to view the LICENSE that way, which should
* always be possible within a valid and working OCL release,
* please write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* to get a copy of the GNU General Public License or to report a
* possible license violation.
*/
import java.util.Arrays;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
/**
* Conversion utilities.
*
* @since beta 1
* @version beta 1<br />CVS $Revision: 1.8 $ $Author: istr $
* @author <a href="mailto:ingo@ingostruck.de">ingo@ingostruck.de</a>
*/
public final class Convert {
/** Revision identifier */
public static final String MODULE = "<Convert beta 1, CVS $Revision: 1.8 $>";
/** to mimic sizeof(short) = short length in bytes = 12 (=16bit) */
public static final int SIZEOF_SHORT = 2;
/** to mimic sizeof(int) = int length in bytes = 4 (=32bit) */
public static final int SIZEOF_INT = 4;
/** to mimic sizeof(long) = long length in bytes = 8 (=64bit) */
public static final int SIZEOF_LONG = 8;
/** bit length of byte */
public static final int BITS_BYTE = 8;
/** bit length of short */
public static final int BITS_SHORT = BITS_BYTE * SIZEOF_SHORT;
/** bit length of int */
public static final int BITS_INT = BITS_BYTE * SIZEOF_INT;
/** bit length of long */
public static final int BITS_LONG = BITS_BYTE * SIZEOF_LONG;
/** mask a byte in an int */
public static final int MASK_BYTE = 0xFF;
/** Avoids instantiation */
private Convert () {}
/**
* Converts the SIZEOF_LONG bytes starting at off within b to a long value.
* <br />NOTE: the conversion treats the leftmost byte as the lowest byte of
* the resulting long value
* @param b a byte[] containing bytes to be converted
* @param off the offset where to find the bytes to be converted
* @return a long value
* @throws IndexOutOfBoundsException if an index violation occurs
*/
public static long toLong ( byte[] b, int off ) {
long r = 0;
for ( int i = SIZEOF_LONG - 1; i >= 0; i-- )
r |= (((long) b[ off + i ]) & MASK_BYTE) << (i*BITS_BYTE);
return r;
}
/**
* Converts the SIZEOF_INT bytes starting at off within b to an int value.
* <br />NOTE: the conversion treats the leftmost byte as the lowest byte of
* the resulting int value
* @param b a byte[] containing bytes to be converted
* @param off the offset where to find the bytes to be converted
* @return an int value
* @throws IndexOutOfBoundsException if an index violation occurs
*/
public static int toInt ( byte[] b, int off ) {
int r = 0;
for ( int i = SIZEOF_INT - 1; i >= 0; i-- )
r |= ((int) (b[ off + i ] & MASK_BYTE)) << (i*BITS_BYTE);
return r;
}
/**
* Converts a long value to SIZEOF_LONG bytes stored in b starting at off.
* <br />NOTE: the conversion stores the lowest byte of the long value as
* the leftmost byte within the sequence
* @param val a long value to be split up into bytes
* @param b a byte[] to be written to
* @param off the offset where to start writing within b
* @throws IndexOutOfBoundsException if an index violation occurs
*/
public static void toBytes ( long val, byte[] b, int off ) {
for ( int i = 0; i < SIZEOF_LONG; i++, val >>= BITS_BYTE )
b[ off + i ] = (byte) (val & MASK_BYTE);
}
/**
* Converts an int value to SIZEOF_INT bytes stored in b starting at off.
* <br />NOTE: the conversion stores the lowest byte of the int value as
* the leftmost byte within the sequence
* @param val an int value to be split up into bytes
* @param b a byte[] to be written to
* @param off the offset where to start writing within b
* @throws IndexOutOfBoundsException if an index violation occurs
*/
public static void toBytes ( int val, byte[] b, int off ) {
for ( int i = 0; i < SIZEOF_INT; i++, val >>= BITS_BYTE )
b[ off + i ] = (byte) (val & MASK_BYTE);
}
/**
* Converts a byte value to a hexadecimal String.
* @param b a byte value
* @return a hexadecimal (upper-case-based) String representation of the
* byte value
*/
public static String toHexString ( byte b ) {
int len = 2;
byte[] dig = new byte[ len ];
dig[ 0 ] = (byte) ((b & 0xF0) >> 4);
dig[ 1 ] = (byte) (b & 0x0F);
for ( int i = 0; i < len; i++ )
dig[ i ] += 10 > dig[ i ] ? 48 : 55;
return new String( dig );
}
public static String toHexString ( byte[] b ) {
if ( null == b )
return null;
int len = b.length;
byte[] hex = new byte[ len << 1 ];
for ( int i = 0, j = 0; i < len; i++, j+=2 ) {
hex[ j ] = (byte) ((b[ i ] & 0xF0) >> 4);
hex[ j ] += 10 > hex[ j ] ? 48 : 55;
hex[ j + 1 ] = (byte) (b[ i ] & 0x0F);
hex[ j + 1 ] += 10 > hex[ j + 1 ] ? 48 : 55;
}
return new String( hex );
}
/**
* Parses a number from a string.
* Finds the first recognizable base-10 number (integer or floating point)
* in the string and returns it as a Number.
* @param string String to parse
* @return first recognizable number
* @exception NumberFormatException if no recognizable number is found
*/
public static Number toNumber ( String s )
throws NumberFormatException
{
// parsing states
int INT = 0;
int FRAC = 1;
int EXP = 2;
int p = 0;
for ( int i = 0; i < s.length(); ++i ) {
char c = s.charAt( i );
if ( Character.isDigit( c ) ) {
int start = i;
int end = ++i;
int state = INT;
if ( start > 0 && s.charAt( start - 1 ) == '.' ) {
--start;
state = FRAC;
}
if ( start > 0 && s.charAt( start - 1 ) == '-' )
--start;
boolean atEnd = false;
while ( !atEnd && i < s.length() ) {
switch ( s.charAt( i ) ) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
end = ++i;
break;
case '.':
if ( state == INT ) {
state = FRAC;
++i;
} else {
atEnd = true;
}
break;
case 'e':
case 'E':
state = EXP;
++i;
if ( i < s.length() && ((c = s.charAt( i )) == '+' || c == '-') )
++i;
break;
default:
atEnd = true;
}
}
String num = s.substring( start, end );
try {
if ( state == INT )
return new Integer( num );
else
return new Double( num );
}
catch ( NumberFormatException e ) {
throw new RuntimeException( "internal error: " + e );
}
}
}
throw new NumberFormatException( s );
}
public static String[] toStrings( Object[] o ) {
if ( null == o )
return null;
int len = o.length;
String[] s = new String[ len ];
for ( int i = 0; i < len; i++ )
if ( null != o[ i ] )
s[ i ] = o[ i ].toString();
return s;
}
/** converts to int with radix 10 and default 0 */
public static int toInt ( Object o ) {
return toInt( o, 10, 0 );
}
/**
* Convets an Object to an int value using radix 10.
* <br />This is a wrapper for
* <code>{@link #toInt( Object, int ) toInt( o, 10 )}</code>.
* @param o Object to be converted to integer
* @return the int value represented by o or 0 if conversion fails.
*/
public static int toInt ( Object o, int dflt ) {
return toInt( o, 10, dflt );
}
/**
* Converts any String representation to an int value using a given radix.
* <br />For <code>null</code> it returns <code>0</code>.<br />
* For Objects instanceof Number it returns the Object's
* <code>intValue()</code>.
* For all other Objects it uses the <code>toString()</code> method to get an
* appropriate String representation and parses this String using
* <code>Integer.parseInt</code>.
* If conversion fails it returns <code>0</code>.
* @param o Object to be converted to integer
* @param radix the radix used for conversion
* @return the int value represented by <code>o</code> or <code>0</code>
* if conversion fails.
*/
public static int toInt ( Object o, int radix, int dflt ) {
if ( null == o ) // shortcut without exception
return dflt;
if ( o instanceof Number )
return ((Number) o).intValue();
try {
return Integer.parseInt( o.toString().trim(), radix );
}
catch ( Exception e ) {
return dflt;
}
}
public static long toLong ( Object o ) {
return toLong( o, 10, 0 );
}
public static long toLong ( Object o, int dflt ) {
return toLong( o, 10, dflt );
}
public static long toLong ( Object o, int radix, int dflt ) {
if ( null == o ) // shortcut without exception
return dflt;
if ( o instanceof Number )
return ((Number) o).longValue();
try {
return Long.parseLong( o.toString().trim(), radix );
}
catch ( Exception e ) {
return dflt;
}
}
} // class Convert
