How to create methods in Java apache velocity using #macro with Example

#macro is a method creation statement in VTL. #macro used to create user defined or custom function or methods in Apache velocity template. The below Example is created with parameterized #macro.

UserInfo

public class UserInfo{
    private int rollno;
    private String username;
    private int age;
    private String sex;
     
    public int getRollno() {
        return rollno;
    }
    public void setRollno(int rollno) {
        this.rollno = rollno;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
}

MacroVTLExample

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
 
import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;
 
public class MacroVTLExample {
    public static void main(String args[]){
        VelocityEngine ve = new VelocityEngine();
        ve.init();
          
        Template t = ve.getTemplate("velocitytemplate.vm");
          
        VelocityContext vc = new VelocityContext();
        List<UserInfo> userInfoList = new ArrayList<UserInfo>();
        {
            UserInfo userinfo = new UserInfo();
            userinfo.setRollno(1001);
            userinfo.setUsername("Parthasarathy");
            userinfo.setAge(22);
            userinfo.setSex("male");
             
            userInfoList.add(userinfo);
        }
        {
            UserInfo userinfo = new UserInfo();
            userinfo.setRollno(1002);
            userinfo.setUsername("Lakshanya");
            userinfo.setAge(12);
            userinfo.setSex("female");
             
            userInfoList.add(userinfo);
        }
         
        vc.put("user_info_list", userInfoList);
         
        StringWriter sw = new StringWriter();
        t.merge(vc, sw);
          
        System.out.println(sw);
    }
}

Velocitytemplate.vm

#macro (display $userinfo)
    RollNo: $userinfo.getRollno()
   Username: $userinfo.getUsername()
   Age: $userinfo.getAge()
   Sex: $userinfo.getSex()
#end

User Details
------------
#foreach ($userinfo in $user_info_list)
   #display($userinfo)
#end

Output

User Details
------------
RollNo: 1001
Username: Parthasarathy
Age: 22
Sex: male

RollNo: 1002
Username: Lakshanya
Age: 12
Sex: female

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