Thursday, January 29, 2026
HomeLanguagesJavaCollections synchronizedMap() method in Java with Examples

Collections synchronizedMap() method in Java with Examples

The synchronizedMap() method of java.util.Collections class is used to return a synchronized (thread-safe) map backed by the specified map. In order to guarantee serial access, it is critical that all access to the backing map is accomplished through the returned map.

Syntax:

public static <K, V> Map<K, V> synchronizedMap(Map<K, V> m)

Parameters: This method takes the map as a parameter to be “wrapped” in a synchronized map.

Return Value: This method returns a synchronized view of the specified map.

Below are the examples to illustrate the synchronizedMap() method.

Example 1:




// Java program to demonstrate
// synchronizedMap() method
// for <String, String> Value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
  
        try {
  
            // creating object of Map<String, String>
            Map<String, String>
                map = new HashMap<String, String>();
  
            // populate the map
            map.put("Value1", "20");
            map.put("Value2", "30");
            map.put("Value3", "40");
  
            // printing the Collection
            System.out.println("Map : " + map);
  
            // create a synchronized map
            Map<String, String>
                synmap = Collections.synchronizedMap(map);
  
            // printing the Collection
            System.out.println("Synchronized map is : "
                               + synmap);
        }
  
        catch (IllegalArgumentException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}


Output:

Map : {Value3=40, Value1=20, Value2=30}
Synchronized map is : {Value3=40, Value1=20, Value2=30}

Example 2:




// Java program to demonstrate
// synchronizedMap() method
// for <String, Boolean> Value
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] argv)
        throws Exception
    {
  
        try {
  
            // creating object of Map<String, Boolean>
            Map<String, Boolean>
                map = new HashMap<String, Boolean>();
  
            // populate the map
            map.put("Bramha", true);
            map.put("Vishnu", true);
            map.put("Mahesh", true);
  
            // printing the Collection
            System.out.println("Map : " + map);
  
            // create a synchronized map
            Map<String, Boolean>
                synmap = Collections.synchronizedMap(map);
  
            // printing the Collection
            System.out.println("Synchronized map is : "
                               + synmap);
        }
        catch (IllegalArgumentException e) {
  
            System.out.println("Exception thrown : " + e);
        }
    }
}


Output:

Map : {Bramha=true, Vishnu=true, Mahesh=true}
Synchronized map is : {Bramha=true, Vishnu=true, Mahesh=true}
Dominic
Dominichttp://wardslaus.com
infosec,malicious & dos attacks generator, boot rom exploit philanthropist , wild hacker , game developer,
RELATED ARTICLES

2 COMMENTS

Most Popular

Dominic
32477 POSTS0 COMMENTS
Milvus
122 POSTS0 COMMENTS
Nango Kala
6849 POSTS0 COMMENTS
Nicole Veronica
11978 POSTS0 COMMENTS
Nokonwaba Nkukhwana
12065 POSTS0 COMMENTS
Shaida Kate Naidoo
6986 POSTS0 COMMENTS
Ted Musemwa
7221 POSTS0 COMMENTS
Thapelo Manthata
6934 POSTS0 COMMENTS
Umr Jansen
6916 POSTS0 COMMENTS