Java Collections unmodifiableSortedSet() Method

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Description

The Java Collections unmodifiableSortedSet() method is used to return a immutable (thread-safe) sorted set backed by the specified sorted set.

Declaration

Following is the declaration for java.util.Collections.unmodifiableSortedSet() method.

public static <T> SortedSet<T> unmodifiableSortedSet(SortedSet<T> s)

Parameters

s − This is the sorted set to be "wrapped" in a immutable sorted set.

Return Value

• The method call returns a immutable view of the specified sorted set.

Exception

NA

Getting Immutable Set From a SortedSet of Integer Example

The following example shows the usage of Java Collection unmodifiableSortedSet(SortedSet) method. We've created a SortedSet object of Integer. Few entries are added and then using unmodifiableSortedSet(SortedSet) method, we've retrieved the immutable version of sorted set and printed the sorted set.

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeSet;
import java.util.SortedSet;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create sorted set
      SortedSet<Integer> sortedSet = new TreeSet<Integer>();

      // populate the sorted set
      sortedSet.add(1); 
      sortedSet.add(2);
      sortedSet.add(3);

      // create a immutable sorted set
      SortedSet<Integer> immutableSet = Collections.unmodifiableSortedSet(sortedSet);

      System.out.println("Immutable sorted set is :"+immutableSet);
   }
}

Output

Let us compile and run the above program, this will produce the following result.

Immutable sorted set is :[1, 2, 3]

Getting Immutable Set From a SortedSet of String Example

The following example shows the usage of Java Collection unmodifiableSortedSet(SortedSet) method. We've created a SortedSet object of String and String. Few entries are added and then using unmodifiableSortedSet(SortedSet) method, we've retrieved the immutable version of map and printed the map.

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeSet;
import java.util.SortedSet;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create sorted set
      SortedSet<String> sortedSet = new TreeSet<String>();

      // populate the sorted set
      sortedSet.add("TP"); 
      sortedSet.add("IS");
      sortedSet.add("BEST");

      // create a immutable sorted set
      SortedSet<String> immutableSet = Collections.unmodifiableSortedSet(sortedSet);

      System.out.println("Immutable sorted set is :"+immutableSet);
   }
}

Output

Let us compile and run the above program, this will produce the following result.

Immutable sorted set is :[BEST, IS, TP]

Getting Immutable Set From a SortedSet of Object Example

The following example shows the usage of Java Collection unmodifiableSortedSet(SortedSet) method. We've created a SortedSet object of String and Student object. Few entries are added and then using unmodifiableSortedSet(SortedSet) method, we've retrieved the immutable version of map and printed the map.

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeSet;
import java.util.SortedSet;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create sorted set
      SortedSet<Student> sortedSet = new TreeSet<Student>();

      // populate the sorted set
      sortedSet.add(new Student(1, "Julie")); 
      sortedSet.add(new Student(2, "Robert"));
      sortedSet.add(new Student(3, "Adam"));

      // create a immutable sorted set
      SortedSet<Student> immutableSet = Collections.unmodifiableSortedSet(sortedSet);

      System.out.println("Immutable sorted set is :"+immutableSet);
   }
}
class Student implements Comparable<Student> {
   int rollNo;
   String name;

   Student(int rollNo, String name){
      this.rollNo = rollNo;
      this.name = name;
   }

   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]";
   }
   
   @Override
   public boolean equals(Object obj) {
      Student s = (Student)obj;
      return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name);
   }

   @Override
   public int compareTo(Student student) {
      return this.rollNo - student.rollNo;
   }
}

Output

Let us compile and run the above program, this will produce the following result.

Immutable sorted set is :[[ 1, Julie ], [ 2, Robert ], [ 3, Adam ]]