Java Guava | Bytes.concat() method with Examples

Last Updated : 31 Jan, 2019

The concat() method of Bytes Class in the Guava library is used to concatenate the values of many arrays into a single array. These byte arrays to be concatenated are specified as parameters to this method.

For example: concat(new byte[] {1, 2}, new byte[] {3, 4, 5}, new byte[] {6, 7}
returns the array {1, 2, 3, 4, 5, 6, 7}.

Syntax:

public static byte[] concat(byte[]... arrays)

Parameter: This method accepts arrays as parameter which is the byte arrays to be concatenated by this method.

Return Value: This method returns a single byte array which contains all the specified byte array values in its original order.

Below programs illustrate the use of concat() method:

Example 1:

// Java code to show implementation of 
// Guava's Bytes.concat() method 
  
import com.google.common.primitives.Bytes; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        // Creating 2 Byte arrays 
        byte[] arr1 = { 1, 2, 3, 4, 5 }; 
        byte[] arr2 = { 6, 2, 7, 0, 8 }; 
  
        // Using Bytes.concat() method to combine 
        // elements from both arrays into a single array 
        byte[] res = Bytes.concat(arr1, arr2); 
  
        // Displaying the single combined array 
        System.out.println(Arrays.toString(res)); 
    } 
} 

Output:

[1, 2, 3, 4, 5, 6, 2, 7, 0, 8]

Example 2:

// Java code to show implementation of 
// Guava's Bytes.concat() method 
  
import com.google.common.primitives.Bytes; 
import java.util.Arrays; 
  
class GFG { 
  
    // Driver's code 
    public static void main(String[] args) 
    { 
  
        // Creating 4 byte arrays 
        byte[] arr1 = { 1, 2, 3 }; 
        byte[] arr2 = { 4, 5 }; 
        byte[] arr3 = { 6, 7, 8 }; 
        byte[] arr4 = { 9, 0 }; 
  
        // Using Bytes.concat() method to combine 
        // elements from both arrays into a single array 
        byte[] res = Bytes.concat(arr1, arr2, arr3, arr4); 
  
        // Displaying the single combined array 
        System.out.println(Arrays.toString(res)); 
    } 
} 