hex : Java Glossary

Displaying With Hex Strings

You

Hex with Lead Zeroes

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

The method com.mindprod.common18.ST. toHexString is useful for debugging. It will give you an 8-char left-zero padded hex String representation of an

// 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.common18.ST. toLzHexString will pad out

Hex String to int

/* 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.

String to hex String

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

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

byte[] to String

String to byte[]

Here is a low-level routine to parse a hex string to byte array.

Hex Literals

Hex literal are written with a lead 0x. byte literals are usually padded out to 2 digits, e.g. 0x0f. short and char literals are usually padded out to 4 digits, e.g. 0x00ff. int literals are sometimes padded out to 8 digits, e.g. 0x000022ff. long literals are sometimes padded out to 16 digits, e.g. 0x0000000010000022ff. Unfortunately, Java does not allow commas to break long literals into groups of four digits. You can insert spaces to proofread then remove them to compile. Ideally editors would work like JDisplay, showing groups in slightly different alternating colours as in the following example.

// example of a hex 0x literal broken into groups by of four
// by colour for easy proofreading.

int a = 0x00aceb777708cf;

Hex vs Decimal vs Binary

Table of Hex digits

Hex Color Numbers

Learning More