Arrays.copyOfRange(byte[], int, int) in Java

Arrays.copyOfRange(byte[], int, int): This method is available in java.util.Arrays class of Java.

Syntax:

byte[] java.util.Arrays.copyOfRange(byte[] original, int from, int to)

This method takes three arguments one of type byte array and the other two are of type int as its parameters. This method copies the specified range of the specified array into a new array.

Parameters: Three parameters are required for this method.

original: the array from which a range is to be copied.

from: the initial index of the range to be copied, inclusive.

to: the final index of the range to be copied, exclusive.

Returns: a new array containing the specified range from the original array, truncated or padded with zeros to obtain the required length.

Throws:

1. ArrayIndexOutOfBoundsException - if from < 0or from > original.length.

2. IllegalArgumentException - if from > to.

3. NullPointerException - if original is null.

Approach 1: When no exceptions

Java

import java.util.Arrays;

public class ArrayscopyOfRangebyte {
    public static void main(String[] args) {

        byte orininal[] = { 1, 2, 3, 4 };
        int from = 0, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal, 
                                                     from, to)));
    }
}

Output:

[1, 2]

Approach 2: ArrayIndexOutOfBoundsException 

Java

import java.util.Arrays;

public class ArrayscopyOfRangebyte {
    public static void main(String[] args) {

        byte orininal[] = { 1, 2, 3, 4 };
        int from = -1, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal, 
                                                        from, to)));
    }
}

Output:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: arraycopy: source index -1 out of bounds for byte[4]
	at java.base/java.lang.System.arraycopy(Native Method)
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3822)
	

Approach 3: IllegalArgumentException

Java

import java.util.Arrays;

public class ArrayscopyOfRangebyte {
    public static void main(String[] args) {

        byte orininal[] = { 1, 2, 3, 4 };
        int from = 5, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal, 
                                                from, to)));
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: 5 > 2
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3820)
	

Approach 4: NullPointerException

Java

import java.util.Arrays;

public class ArrayscopyOfRangebyte {
    public static void main(String[] args) {

        byte orininal[] = null;
        int from = 0, to = 2;
        System.out.println(Arrays.toString(Arrays.copyOfRange(orininal, 
                                                     from, to)));
    }
}

Output:

Exception in thread "main" java.lang.NullPointerException: Cannot read the array length because "original" is null
	at java.base/java.util.Arrays.copyOfRange(Arrays.java:3822)