hex : Java Glossary

Displaying With Hex Strings

That won’t apply any lead zeroes. Here is how to get a lead zero for a fixed two character hex representation of a byte:

// convert a single byte b to a 2-char hex string
// with possible leading zero.
String s2 = Integer.toString( ( b & 0xff ) + 0x100, 16 /* radix */ ).substring( 1 );

The method com.mindprod.common11.StringTools. toHexString is useful for debugging. It will give you an 8-char left-zero padded hex String representatation of an int.

// Available in download http://mindprod.com/products1.html#COMMON11
import com.mindprod.common11.StringTools;
...
// Prepare unsigned hex string padded out to 8 chars with lead zeroes.
final String display = StringTools.toHexString( someInt );

The method com.mindprod.common11.StringTools. toLzHexString will pad out to any desired size with lead zeros for you:

// Available in download http://mindprod.com/products1.html#COMMON11
import com.mindprod.common11.StringTools;
...
// Prepare unsigned hex string padded out to 4 places with lead zeroes.
final String display = StringTools.toLzHexString( value, 4 /* desired length */ );

/* convert a hex String to int */
// Note, there is no lead 0x, case insensitive
String g = "af0c99";
int i = Integer.parseInt( g.trim(), 16 /* radix */ );

Since the computer uses binary internally, it makes no sense to talk about converting an int from hex to decimal or back, only a String.

Here is how you can convert a String to hex for display so you can tell precisely what each character is.

Use can also use Printwriter.printf( "%x", i ) to display a hex number.

byte[] to String

String to byte[]

Hex Literals

// example of a hex 0x literal
int a = 0x8cf;

Hex vs Decimal vs Binary

Table of Hex digits

Hex Color Numbers