Java Message Format Using Named Placeholder

The Java MessageFormat class allows user to pre-define a string with placeholders and then fill the placeholders with actual strings later to construct a proper message.

It's all fine if you're used to numbered placeholders e.g. {0} and {1}.

Apache Commons has a StrSubstitutor class which allows use of named placeholders.

Although StrSubstitutor is a bit more verbose, but it helps when you're handling lots of key/value pairs.

import java.util.HashMap;

import java.util.Map;

import org.apache.commons.lang3.text.StrSubstitutor;

public class MessagePlaceHolder {

     

      public static void main(String[] args) {

            Map<String,String> map = new HashMap<String, String>();

            map.put("name", "Rajesh");

            map.put("email", "rkdixit3@gmail.com");

           

            String format = "Hello {name}, your email is {email}.";

            String message = StrSubstitutor.replace(format,map,"{","}");

            System.out.println(message);

      }

}

Output:

Hello Rajesh, your email is rkdixit3@gmail.com.