Longs Class | Guava | Java

Longs is a utility class for primitive type long. It provides Static utility methods pertaining to long primitives, that are not already found in either Long or Arrays.

Declaration :

@GwtCompatible(emulated=true)
public final class Longs
extends Object

Below table shows the Field summary for Guava Longs Class :

Some of the methods provided by Guava Longs Class are :

Exceptions :

• min : IllegalArgumentException if array is empty.
• max : IllegalArgumentException if array is empty.
• fromByteArray : IllegalArgumentException if bytes has fewer than 8 elements.
• ensureCapacity : IllegalArgumentException if minLength or padding is negative.
• toArray : NullPointerException if collection or any of its elements is null.

Below table shows some other methods provided by Guava Longs Class :

Below given are some examples showing the implementation of methods of Guava Longs Class :
Example 1 :

// Java code to show implementation
// of Guava Longs.asList() method

import com.google.common.primitives.Longs;
import java.util.*;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        long arr[] = { 3L, 4L, 5L, 6L, 7L };

        // Using Longs.asList() method which wraps
        // the primitive long array as List of
        // long Type
        List<Long> myList = Longs.asList(arr);

        // Displaying the elements
        System.out.println(myList);
    }
}

Output :

[3, 4, 5, 6, 7]

Example 2 :

// Java code to show implementation
// of Guava Longs.toArray() method

import com.google.common.primitives.Longs;
import java.util.*;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        List<Long> myList = Arrays.asList(3L, 4L, 5L, 6L, 7L);

        // Using Longs.toArray() method which
        // converts a List of Longs to an
        // array of long
        long[] arr = Longs.toArray(myList);

        // Displaying the elements
        System.out.println(Arrays.toString(arr));
    }
}

Output :

[3, 4, 5, 6, 7]

Example 3 :

// Java code to show implementation
// of Guava Longs.concat() method

import com.google.common.primitives.Longs;
import java.util.*;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        long[] arr1 = { 3L, 4L, 5L };
        long[] arr2 = { 6L, 7L };

        // Using Longs.concat() method which
        // combines arrays from specified
        // arrays into a single array
        long[] arr = Longs.concat(arr1, arr2);

        // Displaying the elements
        System.out.println(Arrays.toString(arr));
    }
}

Output :

[3, 4, 5, 6, 7]

Example 4 :

// Java code to show implementation
// of Guava Longs.contains() method

import com.google.common.primitives.Longs;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        long[] arr = { 3L, 4L, 5L, 6L };

        // Using Longs.contains() method which
        // checks if element is present in array
        // or not
        System.out.println(Longs.contains(arr, 4L));
        System.out.println(Longs.contains(arr, 7L));
    }
}

output :

true
false

Example 5 :

// Java code to show implementation
// of Guava Longs.min() method

import com.google.common.primitives.Longs;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        long[] arr = { 3L, 4L, 5L, 6L };

        // Using Longs.min() method
        System.out.println(Longs.min(arr));
    }
}

Output :

3

Example 6 :

// Java code to show implementation
// of Guava Longs.max() method

import com.google.common.primitives.Longs;

class GFG {
    // Driver method
    public static void main(String[] args)
    {
        long[] arr = { 3L, 4L, 5L, 6L };

        // Using Longs.max() method
        System.out.println(Longs.max(arr));
    }
}

Output :

6