Java Collections unmodifiableNavigableMap() Method

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Description

The Java Collections unmodifiableNavigableMap() method is used to return an unmodifiable view of the specified navigable map.

Declaration

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

public static <K,V> NavigableMap<K,V> unmodifiableNavigableMap(NavigableMap<? extends K,? extends V> m)

Parameters

m − This is the navigable map for which an unmodifiable view is to be returned.

Return Value

• The method call returns an unmodifiable view of the specified navigable map.

Exception

NA

Getting Immutable NavigableMap From a Mutable NavigableMap of String, Integer Example

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

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeMap;
import java.util.NavigableMap;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create map
      NavigableMap<String,Integer> map = new TreeMap<String,Integer>();

      // populate the map
      map.put("1",1); 
      map.put("2",2);
      map.put("3",3);

      // create a navigable map
      NavigableMap<String,Integer> navigableMap = Collections.unmodifiableNavigableMap(map);

      System.out.println("Immutable Navigable map is :"+navigableMap);
   }
}

Output

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

Immutable Navigable map is :{1=1, 2=2, 3=3}

Getting Immutable NavigableMap From a Mutable NavigableMap of String, String Example

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

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeMap;
import java.util.NavigableMap;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create map
      NavigableMap<String,String> map = new TreeMap<String,String>();

      // populate the map
      map.put("1","TP"); 
      map.put("2","IS");
      map.put("3","BEST");

      // create a navigable map
      NavigableMap<String,String> navigableMap = Collections.unmodifiableNavigableMap(map);

      System.out.println("Immutable Navigable map is :"+navigableMap);
   }
}

Output

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

Immutable Navigable map is :{1=TP, 2=IS, 3=BEST}

Getting Immutable NavigableMap From a Mutable NavigableMap of String, Object Example

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

package com.tutorialspoint;

import java.util.Collections;
import java.util.TreeMap;
import java.util.NavigableMap;

public class CollectionsDemo {
   public static void main(String[] args) {
      
      // create map
      NavigableMap<String,Student> map = new TreeMap<String,Student>();

      // populate the map
      map.put("1",new Student(1, "Julie")); 
      map.put("2",new Student(2, "Robert"));
      map.put("3",new Student(3, "Adam"));

      // create a navigable map
      NavigableMap<String,Student> navigableMap = Collections.unmodifiableNavigableMap(map);

      System.out.println("Immutable Navigable map is :"+navigableMap);
   }
}
class 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 + " ]";
   }
}

Output

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

Immutable Navigable map is :{1=[ 1, Julie ], 2=[ 2, Robert ], 3=[ 3, Adam ]}