Guava - Bytes Class

Bytes is a utility class for primitive type byte.

Class Declaration

Following is the declaration for com.google.common.primitives.Bytes class −

@GwtCompatible
public final class Bytes
   extends Object

Class Methods

Sr.No	Method & Description
1	static List<Byte> asList(byte... backingArray) Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]).
2	static byte[] concat(byte[]... arrays) Returns the values from each provided array combined into a single array.
3	static boolean contains(byte[] array, byte target) Returns true if the target is present as an element anywhere in array.
4	static byte[] ensureCapacity(byte[] array, int minLength, int padding) Returns an array containing the same values as the array, but guaranteed to be of a specified minimum length.
5	static int hashCode(byte value) Returns a hash code for value; equal to the result of invoking ((Byte) value).hashCode().
6	static int indexOf(byte[] array, byte target) Returns the index of the first appearance of the value target in array.
7	static int indexOf(byte[] array, byte[] target) Returns the start position of the first occurrence of the specified target within the array, or -1 if there is no such occurrence.
8	static int lastIndexOf(byte[] array, byte target) Returns the index of the last appearance of the value target in array.
9	static byte[] toArray(Collection<? extends Number> collection) Returns an array containing each value of collection, converted to a byte value in the manner of Number.byteValue().

Methods Inherited

This class inherits methods from the following class −

• java.lang.Object

Example - Converting Byte Array to List and vice versa

GuavaTester.java

package com.tutorialspoint;

import java.util.List;

import com.google.common.primitives.Bytes;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBytes();
   }

   private void testBytes() {
      byte[] byteArray = {1,2,3,4,5,5,7,9,9};

      //convert array of primitives to array of objects
      List<Byte> objectArray = Bytes.asList(byteArray);
      System.out.println(objectArray.toString());

      //convert array of objects to array of primitives
      byteArray = Bytes.toArray(objectArray);
      System.out.print("[ ");
      
      for(int i = 0; i< byteArray.length ; i++) {
         System.out.print(byteArray[i] + " ");
      }

      System.out.println("]");
   }
}

Output

Run the GuavaTester and verify the output −

[1, 2, 3, 4, 5, 5, 7, 9, 9]
[ 1 2 3 4 5 5 7 9 9 ]

Example - Checking element in a Byte Array

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Bytes;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBytes();
   }

   private void testBytes() {
      byte[] byteArray = {1,2,3,4,5,5,7,9,9};
      byte data = 5;
      //check if element is present in the list of primitives or not
      System.out.println("5 is in list ? " + Bytes.contains(byteArray, data));
      data = 6;
	  System.out.println("6 is in list ? " + Bytes.contains(byteArray, data));
   }
}

Output

Run the GuavaTester and verify the output −

5 is in list ? true
6 is in list ? false

Example - Getting Index and Last Index of Element in Byte Array

GuavaTester.java

package com.tutorialspoint;

import com.google.common.primitives.Bytes;

public class GuavaTester {
   public static void main(String args[]) {
      GuavaTester tester = new GuavaTester();
      tester.testBytes();
   }

   private void testBytes() {
      byte[] byteArray = {1,2,3,4,5,5,7,9,9};
      byte data = 5;
      //Returns the index
      System.out.println("Index of 5: " + Bytes.indexOf(byteArray,data));

      //Returns the last index maximum
      System.out.println("Last index of 5: " + Bytes.lastIndexOf(byteArray,data));
   }
}

Output

Run the GuavaTester and verify the output −

Index of 5: 4
Last index of 5: 5