You can use an utility function to convert from the familiar hexa string to a byte[].
When used to define a final static constant, the performance cost is irrelevant.
Since Java 17
There's now java.util.HexFormat which lets you do
byte[] CDRIVES = HexFormat.of().parseHex("e04fd020ea3a6910a2d808002b30309d");
This utility class lets you specify a format which is handy if you find other formats easier to read or when you're copy-pasting from a reference source:
byte[] CDRIVES = HexFormat.ofDelimiter(":")
.parseHex("e0:4f:d0:20:ea:3a:69:10:a2:d8:08:00:2b:30:30:9d");
Before Java 17
I'd suggest you use the function defined by Dave L in Convert a string representation of a hex dump to a byte array using Java?
byte[] CDRIVES = hexStringToByteArray("e04fd020ea3a6910a2d808002b30309d");
I insert it here for maximum readability :
public static byte[] hexStringToByteArray(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
Top answer 1 of 11
163
You can use an utility function to convert from the familiar hexa string to a byte[].
When used to define a final static constant, the performance cost is irrelevant.
Since Java 17
There's now java.util.HexFormat which lets you do
byte[] CDRIVES = HexFormat.of().parseHex("e04fd020ea3a6910a2d808002b30309d");
This utility class lets you specify a format which is handy if you find other formats easier to read or when you're copy-pasting from a reference source:
byte[] CDRIVES = HexFormat.ofDelimiter(":")
.parseHex("e0:4f:d0:20:ea:3a:69:10:a2:d8:08:00:2b:30:30:9d");
Before Java 17
I'd suggest you use the function defined by Dave L in Convert a string representation of a hex dump to a byte array using Java?
byte[] CDRIVES = hexStringToByteArray("e04fd020ea3a6910a2d808002b30309d");
I insert it here for maximum readability :
public static byte[] hexStringToByteArray(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
2 of 11
126
byte[] myvar = "Any String you want".getBytes();
String literals can be escaped to provide any character:
byte[] CDRIVES = "\u00e0\u004f\u00d0\u0020\u00ea\u003a\u0069\u0010\u00a2\u00d8\u0008\u0000\u002b\u0030\u0030\u009d".getBytes();
Medium
medium.com › @rrlinus5 › stream-of-bytes-internal-concept-java-831c4d94ad4c
Stream of bytes internal concept — Java | by Rakesh raj | Medium
March 2, 2024 - Stream of bytes internal concept — Java What is a byte array? A byte array in Java is simply an array of bytes. It’s a contiguous block of memory allocated to store byte values. Each element in …
Java help with byte arrays
Concatenate the strings together first? More on reddit.com
19
2
November 13, 2016Can some explain byte arrays?
A byte is eight bits, where each bit is a 0 or a 1. Think of them as an integer in the range 0..255. (n = 1 * bit0 + 2 * bit1 + 4 * bit2 + ... + (27 ) * bit7). The computer can also recognize a byte as an integer in the range -128..+127 (see two's complement ). So you can store a small number in each byte. A byte array is a sequence of bytes that you can access independently, like a mathematical vector or column of data. For example, if you have an array of 10 bytes, call it myarray[10]. You can store data in it: myarray[0] = 1 myarray[1] = 5 .... And you can read data from it: print(myarray[7]) print(myarray[0] + myarray[9]) If you want to store larger numbers, they get spread across multiple adjacent bytes. A common integer size is 4 bytes, which is 32 bits, which lets you store integers from 0 to about 4 billion (232 - 1). Real numbers are stored as "floating point" numbers, which are store in a more complicated format . If your computer has 4 gigabytes of memory, then its memory is a big byte array with 4 * (230 ) entries in it. Programs aren't allowed to access all the memory directly, mostly so they don't mess with data that belongs to other programs. What you usually do is tell the system, "I need 200 bytes of memory", and it will return the location of the memory you're allowed to use. Say it returns the location 2500. Then you're allowed to read and write memory locations 2500..2699. If you try to read or write from some other location, it will most likely belong to some other program, and the system will kill your program for trying to do an illegal operation. That whole process gets a bit complicated, but if you're curious, see virtual memory . More on reddit.com
5
5
February 28, 2018[Java] Is Storing an Audio File in a Byte Array possible?
You can store any file in a byte array. A file is nothing more than a sequence of bytes. An array can hold 4GB2GB worth of data. I'm pretty sure your .mid files are smaller. You should post your code; good chance that you're not reading the file correctly. More on reddit.com
8
1
October 8, 2015Converting byte array to hex string in java
Could you give some example code, and some example input and output? More on reddit.com
4
1
January 18, 201908:20
Bytearray Explained for beginners - YouTube
04:06
Java: Convert String to Byte Array - Video | Study.com
Java Program to Convert Byte Array to File | Copy One file to ...
Java Program to Convert File to Byte Array
03:28
Java Program to Convert Byte Array to File | Copy One file to Another ...
04:04
How To Convert A String To A Byte Array In Java? - Next LVL ...
Oracle
docs.oracle.com › cd › E14571_01 › apirefs.1111 › e12063 › oracle › dss › util › xdo › common › io › ByteArray.html
ByteArray (Oracle Fusion Middleware Java API Reference for Oracle Data Visualization Components)
java.lang.Object oracle.dss.util.xdo.common.io.ByteArray ... Byte Array handling class. Using this class, you can access memory like RandomAccessFile. Note) Write methods are not implemented yet. ... Reads up to b.length bytes of data from this file into an array of bytes.
Huda Tutorials
hudatutorials.com › java › basics › java-arrays › java-byte-array
Java byte Array - byte Array in Java, initialize, String
February 7, 2022 - The byte is a keyword in Java which designates the 8 bit signed integer primitive type . ... The byte array is an array of bytes.
GitHub
github.com › patrickfav › bytes-java
GitHub - patrickfav/bytes-java: Bytes is a utility library that makes it easy to create, parse, transform, validate and convert byte arrays in Java. It supports endianness as well as immutability and mutability, so the caller may decide to favor performance. · GitHub
Bytes is a utility library that makes it easy to create, parse, transform, validate and convert byte arrays in Java. It supports endianness as well as immutability and mutability, so the caller may decide to favor performance. - patrickfav/bytes-java
Author: patrickfav
DataCamp
datacamp.com › doc › java › byte
byte Keyword in Java: Usage & Examples
Java keywordsIntroduction To JavaJava File HandlingJava Language BasicsJava ArraysJava Object-Oriented Programming ... The byte keyword in Java is a primitive data type that represents an 8-bit signed two's complement integer. It is used to save memory in large arrays where the memory savings ...
W3docs
w3docs.com › home › code snippets › java › how do i initialize a byte array in java?
How do I initialize a byte array in Java? | W3docs
Alternatively, you can use the new operator to create an array of a specified size and then assign values to its elements: byte[] bytes = new byte[10]; bytes[0] = 0x00; bytes[1] = 0x01; bytes[2] = 0x02; // ...
Codemia
codemia.io › home › knowledge hub › how do i initialize a byte array in java?
How do I initialize a byte array in Java? | Codemia
July 30, 2025 - A byte array is a collection of byte type variables. The byte data type in Java is an 8-bit signed integer ranging from -128 to 127.
Dclunie
dclunie.com › pixelmed › software › javadoc › com › pixelmed › utils › ByteArray.html
ByteArray
Extract a portion of a byte array into a new byte array.
Baeldung
baeldung.com › home › java › java string › convert string to byte array and reverse in java
Convert String to Byte Array and Reverse in Java | Baeldung
March 17, 2024 - A String is stored as an array of Unicode characters in Java. To convert it to a byte array, we translate the sequence of characters into a sequence of bytes. For this translation, we use an instance of Charset.
CodeSpeedy
codespeedy.com › home › how to initialize a byte array in java?
How to Initialize a Byte Array in Java - CodeSpeedy
October 28, 2021 - That means we can store the values ... we have seen, a byte is a combination of eight zeros and ones. A byte array is a combination of bytes values....
TutorialsPoint
tutorialspoint.com › java › util › arrays_fill_byte.htm
Java Arrays fill(byte[], byte) Method
Using fill(byte[], byte) method, we're filling the array with a give value and then updated array elements are printed again. package com.tutorialspoint; import java.util.Arrays; public class ArrayDemo { public static void main(String[] args) { // initializing byte array byte arr[] = new byte[] { 10 , 20, 15}; // let us print the values System.out.println("Actual values: "); for (byte value : arr) { System.out.println("Value = " + value); } byte replacement = 0; // using fill for placing value Arrays.fill(arr, replacement); // let us print the values System.out.println("New values after using fill() method: "); for (byte value : arr) { System.out.println("Value = " + value); } } }
Baeldung
baeldung.com › home › java › java array › convert an object to a byte array in java
Convert an Object to a Byte Array in Java | Baeldung
August 7, 2025 - This class has a method named serialize(), which is used to serialize an object to a byte array: ... The above methods have parameters of type Serializable. So, our User class still needs to implement the Serializable interface, just as it did in our plain Java example.
GeeksforGeeks
geeksforgeeks.org › java › convert-string-to-byte-array-in-java-using-getbytesencoding-method
Convert String to Byte Array in Java Using getBytes(encoding) Method - GeeksforGeeks
July 23, 2025 - In order to convert a string literal into a byte array, we have to first convert the sequence of characters into a sequence of bytes and for this conversion, we can use an instance of Charset. It is an abstract class present in java.nio package and it is used to define a mapping between sequence of sixteen-bit UTF-16 code units i.e sequence of character and sequence of bytes.
Daniel Lemire's blog
lemire.me › blog › 2022 › 11 › 22 › what-is-the-size-of-a-byte-array-in-java
What is the size of a byte[] array in Java? – Daniel Lemire's blog
November 22, 2022 - Java allows you to create an array just big enough to contain 4 bytes, like so: byte[] array = new byte[4]; How much memory does this array take? If you have answered "4 bytes", you are wrong.
DigitalOcean
digitalocean.com › community › tutorials › string-byte-array-java
String to byte array, byte array to String in Java | DigitalOcean
Technical tutorials, Q&A, events — This is an inclusive place where developers can find or lend support and discover new ways to contribute to the community.
Oracle
docs.oracle.com › javase › 8 › docs › api › java › lang › Byte.html
Byte (Java Platform SE 8 )
July 21, 2026 - Java™ Platform Standard Ed. 8 ... The Byte class wraps a value of primitive type byte in an object.
Reddit
reddit.com › r/learnprogramming › java help with byte arrays
r/learnprogramming on Reddit: Java help with byte arrays
November 13, 2016 -
I am struggling with some homework. Basically I need to take a bunch of info for a person and store it in a Random Access File. The problem is that the return of the method is byte[] and the only way I can do anything is with a byte[][] where I use getFamilyName.getBytes() and so on until I have all of the information. How do I make it able to store in a byte[]
Top answer 1 of 2
1
Concatenate the strings together first?
2 of 2
1
I'm guessing you would have to take all the individual bits of information (first name, last name, etc) and put them together in one long series of bytes. So basically you get the byte array of the first name, then add it to some list of bytes. Then you take the last name, then add that to the same list of bytes. The problem is that once you need to turn these bytes back to information, you can no longer figure out which info belonged to what. Like which part of the bytes is the first name? Which part is the last name? All you have is just a series of bytes. You could solve it by adding some kind of separation charachter like ; or |. Basically what you would end up doing then is taking all the information and putting it together like this: 'John;Smith;Maple Street;Canada;' and then turn that whole bunch to a single byte array. Later when you have to retrieve the information again, you know the everything up to the first ; is the first name, then to the next ; is the last name, etc.
Quora
quora.com › What-can-you-store-in-a-byte-array-in-Java
What can you store in a byte array in Java? - Quora
Answer (1 of 7): You can store whole numbers in it. For the exact, -128 to 127 You can store anything in byte array like you do in int array except that the byte array holds smaller value. A Byte is 8 bit, an Int is 32 bit. So if you want to store small number, using byte will benefit you in term...
Scijava
javadoc.scijava.org › SciJava › org › scijava › util › ByteArray.html
ByteArray (SciJava Javadocs 0-SNAPSHOT API)
Constructs an extensible array of bytes, backed by a fixed-size array.