Java Collections emptyNavigableMap() Method

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Description

The Java Collections emptyNavigableMap() method is used to get the empty navigable map (immutable). This navigable map is serializable.

Declaration

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

public static final <K,V> NavigableMap<K,V> emptyNavigableMap()

Parameters

NA

Return Value

NA

Exception

NA

Getting Empty NavigableMap of String, Integer Pair Example

The following example shows the usage of Java Collection emptyNavigableMap() method to get an empty navigable map of String, Integer pairs. We've created an empty navigable map using emptyNavigableMap() method and then tried adding few elements to it which results in exception.

 
package com.tutorialspoint;

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

public class CollectionsDemo {
   public static void main(String args[]) {
      
      // create an empty navigable map    
      NavigableMap<String, Integer> emptyNavigableMap = Collections.emptyNavigableMap();

      System.out.println("Created empty immutable navigable map: "+emptyNavigableMap);

      // try to add elements
      emptyNavigableMap.put("1", 1);
      emptyNavigableMap.put("2", 2);
   }    
}

Output

Let us compile and run the above program, this will produce the following result. Exception will be thrown as the navigable map is immutable.

Created empty immutable navigable map: {}
Exception in thread "main" java.lang.UnsupportedOperationException
	at java.base/java.util.AbstractMap.put(AbstractMap.java:209)
	at com.tutorialspoint.CollectionsDemo.main(CollectionsDemo.java:15)

Getting Empty NavigableMap of String, String Pair Example

The following example shows the usage of Java Collection emptyNavigableMap() method to get an empty navigable map of String, String pairs. We've created an empty navigable map using emptyNavigableMap() method and then tried adding few elements to it which results in exception.

 
package com.tutorialspoint;

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

public class CollectionsDemo {
   public static void main(String args[]) {
      
      // create an empty navigable map    
      NavigableMap<String, String> emptyNavigableMap = Collections.emptyNavigableMap();

      System.out.println("Created empty immutable navigable map: "+emptyNavigableMap);

      // try to add elements
      emptyNavigableMap.put("1", "A");
      emptyNavigableMap.put("2", "B");
   }    
}

Output

Let us compile and run the above program, this will produce the following result. Exception will be thrown as the navigable map is immutable.

Created empty immutable navigable map: {}
Exception in thread "main" java.lang.UnsupportedOperationException
	at java.base/java.util.AbstractMap.put(AbstractMap.java:209)
	at com.tutorialspoint.CollectionsDemo.main(CollectionsDemo.java:15)

Getting Empty NavigableMap of String, Object Pair Example

The following example shows the usage of Java Collection emptyNavigableMap() method to get an empty navigable map of String, Student object pairs. We've created an empty navigable map using emptyNavigableMap() method and then tried adding few elements to it which results in exception.

 
package com.tutorialspoint;

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

public class CollectionsDemo {
   public static void main(String args[]) {
      
      // create an empty navigable map    
      NavigableMap<String, Object> emptyNavigableMap = Collections.emptyNavigableMap();

      System.out.println("Created empty immutable navigable map: "+emptyNavigableMap);

      // try to add elements
      emptyNavigableMap.put("1", new Student(1, "Julie"));
      emptyNavigableMap.put("2", new Student(2, "Jene"));
   }    
}
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. Exception will be thrown as the navigable map is immutable.

Created empty immutable navigable map: {}
Exception in thread "main" java.lang.UnsupportedOperationException
	at java.base/java.util.AbstractMap.put(AbstractMap.java:209)
	at com.tutorialspoint.CollectionsDemo.main(CollectionsDemo.java:15)