org.apache.tomcat.util.buf: public final class: HexUtils

org.apache.tomcat.util.buf
public final class: HexUtils [javadoc | source]

java.lang.Object
   org.apache.tomcat.util.buf.HexUtils

Library of utility methods useful in dealing with converting byte arrays to and from strings of hexadecimal digits. Code from Ajp11, from Apache's JServ.

author: Craig - R. McClanahan

Field Summary
public static final int[]	DEC	Table for HEX to DEC byte translation.
public static final byte[]	HEX	Table for DEC to HEX byte translation.

Method from org.apache.tomcat.util.buf.HexUtils Summary:
convert, convert, convert2Int

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.apache.tomcat.util.buf.HexUtils Detail:
public static byte[] convert(String digits) { // --------------------------------------------------------- Static Methods ByteArrayOutputStream baos = new ByteArrayOutputStream(); for (int i = 0; i < digits.length(); i += 2) { char c1 = digits.charAt(i); if ((i+1) >= digits.length()) throw new IllegalArgumentException (sm.getString("hexUtil.odd")); char c2 = digits.charAt(i + 1); byte b = 0; if ((c1 >= '0") && (c1 < = '9")) b += ((c1 - '0") * 16); else if ((c1 >= 'a") && (c1 < = 'f")) b += ((c1 - 'a" + 10) * 16); else if ((c1 >= 'A") && (c1 < = 'F")) b += ((c1 - 'A" + 10) * 16); else throw new IllegalArgumentException (sm.getString("hexUtil.bad")); if ((c2 >= '0") && (c2 < = '9")) b += (c2 - '0"); else if ((c2 >= 'a") && (c2 < = 'f")) b += (c2 - 'a" + 10); else if ((c2 >= 'A") && (c2 < = 'F")) b += (c2 - 'A" + 10); else throw new IllegalArgumentException (sm.getString("hexUtil.bad")); baos.write(b); } return (baos.toByteArray()); } Convert a String of hexadecimal digits into the corresponding byte array by encoding each two hexadecimal digits as a byte.
public static String convert(byte[] bytes) { StringBuffer sb = new StringBuffer(bytes.length * 2); for (int i = 0; i < bytes.length; i++) { sb.append(convertDigit((int) (bytes[i] > > 4))); sb.append(convertDigit((int) (bytes[i] & 0x0f))); } return (sb.toString()); } Convert a byte array into a printable format containing a String of hexadecimal digit characters (two per byte).
public static int convert2Int(byte[] hex) { // Code from Ajp11, from Apache's JServ // assert b.length==4 // assert valid data int len; if(hex.length < 4 ) return 0; if( DEC[hex[0]]< 0 ) throw new IllegalArgumentException(sm.getString("hexUtil.bad")); len = DEC[hex[0]]; len = len < < 4; if( DEC[hex[1]]< 0 ) throw new IllegalArgumentException(sm.getString("hexUtil.bad")); len += DEC[hex[1]]; len = len < < 4; if( DEC[hex[2]]< 0 ) throw new IllegalArgumentException(sm.getString("hexUtil.bad")); len += DEC[hex[2]]; len = len < < 4; if( DEC[hex[3]]< 0 ) throw new IllegalArgumentException(sm.getString("hexUtil.bad")); len += DEC[hex[3]]; return len; } Convert 4 hex digits to an int, and return the number of converted bytes.

Method from org.apache.tomcat.util.buf.HexUtils Detail:

 public static byte[] convert(String digits) {
    // --------------------------------------------------------- Static Methods
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	for (int i = 0; i <  digits.length(); i += 2) {
	    char c1 = digits.charAt(i);
	    if ((i+1)  >= digits.length())
		throw new IllegalArgumentException
		    (sm.getString("hexUtil.odd"));
	    char c2 = digits.charAt(i + 1);
	    byte b = 0;
	    if ((c1  >= '0") && (c1 < = '9"))
		b += ((c1 - '0") * 16);
	    else if ((c1  >= 'a") && (c1 < = 'f"))
		b += ((c1 - 'a" + 10) * 16);
	    else if ((c1  >= 'A") && (c1 < = 'F"))
		b += ((c1 - 'A" + 10) * 16);
	    else
		throw new IllegalArgumentException
		    (sm.getString("hexUtil.bad"));
	    if ((c2  >= '0") && (c2 < = '9"))
		b += (c2 - '0");
	    else if ((c2  >= 'a") && (c2 < = 'f"))
		b += (c2 - 'a" + 10);
	    else if ((c2  >= 'A") && (c2 < = 'F"))
		b += (c2 - 'A" + 10);
	    else
		throw new IllegalArgumentException
		    (sm.getString("hexUtil.bad"));
	    baos.write(b);
	}
	return (baos.toByteArray());
}

Convert a String of hexadecimal digits into the corresponding byte array by encoding each two hexadecimal digits as a byte.

 public static String convert(byte[] bytes) {
	StringBuffer sb = new StringBuffer(bytes.length * 2);
	for (int i = 0; i <  bytes.length; i++) {
	    sb.append(convertDigit((int) (bytes[i]  > > 4)));
	    sb.append(convertDigit((int) (bytes[i] & 0x0f)));
	}
	return (sb.toString());
}

Convert a byte array into a printable format containing a String of hexadecimal digit characters (two per byte).

 public static int convert2Int(byte[] hex) {
	// Code from Ajp11, from Apache's JServ
	// assert b.length==4
	// assert valid data
	int len;
	if(hex.length <  4 ) return 0;
	if( DEC[hex[0]]< 0 )
	    throw new IllegalArgumentException(sm.getString("hexUtil.bad"));
	len = DEC[hex[0]];
	len = len < <  4;
	if( DEC[hex[1]]< 0 )
	    throw new IllegalArgumentException(sm.getString("hexUtil.bad"));
	len += DEC[hex[1]];
	len = len < <  4;
	if( DEC[hex[2]]< 0 )
	    throw new IllegalArgumentException(sm.getString("hexUtil.bad"));
	len += DEC[hex[2]];
	len = len < <  4;
	if( DEC[hex[3]]< 0 )
	    throw new IllegalArgumentException(sm.getString("hexUtil.bad"));
	len += DEC[hex[3]];
	return len;
}

Convert 4 hex digits to an int, and return the number of converted bytes.