SortedSet in Java

In Java, SortedSet is an interface that extends the Set interface and is used to store a collection of unique elements in a sorted manner. This means that the elements are sorted in either ascending or descending order based on their natural ordering or a custom ordering provided by the user. The SortedSet interface provides several methods to perform operations on the sorted set of elements.

Here is an example of how to use SortedSet:

import java.util.*;

public class SortedSetExample {
    public static void main(String[] args) {
        SortedSet<String> fruits = new TreeSet<>();
        fruits.add("Apple");
        fruits.add("Banana");
        fruits.add("Grapes");
        fruits.add("Orange");

        System.out.println("Sorted set of fruits: " + fruits);

        SortedSet<Integer> numbers = new TreeSet<>();
        numbers.add(10);
        numbers.add(50);
        numbers.add(20);
        numbers.add(40);

        System.out.println("Sorted set of numbers: " + numbers);
    }
}

In this example, we first create a SortedSet of String objects called fruits and add some elements to it using the add() method. We then print the sorted set of fruits using the toString() method.

We also create a SortedSet of Integer objects called numbers and add some elements to it using the add() method. We then print the sorted set of numbers using the toString() method.

Here are some important methods provided by the SortedSet interface:

1. comparator() – Returns the Comparator used to sort the elements of the set, or null if the natural ordering is used.
2. first() – Returns the first (lowest) element in the set.
3. last() – Returns the last (highest) element in the set.
4. headSet(E toElement) – Returns a sorted set containing elements that are less than the specified element.
5. tailSet(E fromElement) – Returns a sorted set containing elements that are greater than or equal to the specified element.
6. subSet(E fromElement, E toElement) – Returns a sorted set containing elements that are greater than or equal to the first specified element and less than the second specified element.

These methods can be used to perform various operations on the SortedSet.

In addition to the above methods, SortedSet also provides all the methods of the Set interface, such as add(), remove(), contains(), isEmpty(), size(), and clear().

It is important to note that the SortedSet interface does not allow duplicate elements. If you try to add a duplicate element to a SortedSet, it will simply be ignored. Also, the elements of a SortedSet must implement the Comparable interface or you need to provide a custom Comparator to the TreeSet constructor to specify the order in which the elements are sorted.

Here is an example of using a custom Comparator to sort a SortedSet:

import java.util.*;

public class SortedSetExample {
    public static void main(String[] args) {
        SortedSet<String> fruits = new TreeSet<>(new LengthComparator());
        fruits.add("Apple");
        fruits.add("Banana");
        fruits.add("Grapes");
        fruits.add("Orange");

        System.out.println("Sorted set of fruits: " + fruits);
    }
}

class LengthComparator implements Comparator<String> {
    public int compare(String s1, String s2) {
        return s1.length() - s2.length();
    }
}

In this example, we create a SortedSet of String objects called fruits and pass a custom Comparator called LengthComparator to the TreeSet constructor. The LengthComparator class implements the Comparator interface and sorts the elements based on their length. We then add some elements to the SortedSet and print the sorted set of fruits.

Overall, the SortedSet interface provides a way to store a collection of unique elements in a sorted manner, making it easy to retrieve the elements in a sorted order.