Define and use Macro in Velocity

This Example shows you how to define and use macro in velocity template and also shows how to use Iterator in velocity template.

Define and use Macro in Velocity

Define and use Macro in Velocity

     

This Example shows you how to define and use macro in velocity  template and also shows how to use Iterator in velocity  template. The method used in this example are described below:-  
1:- Initialize velocity run time engine through method  init().
2:- Create object of VelocityContext Class.
3:- Create Template class object, Template  class object is used for controlling template methods and properties.

template.merge(context, writer): Merge method of the Template class is used here for merging  the VelocityContext class object to produce the output.

#add($list): This is method defined in
UseMacro.vm file and then call this method that adds all the items of given list and sum will show as output.

 

UseMacro.java

import java.io.*;

import org.apache.velocity.*;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.tools.generic.RenderTool;

public class UseMacro {

  public static void main(String[] argsthrows Exception {
  Velocity.init();
  Template template = Velocity.getTemplate("./src/UseMacro.vm");

  VelocityContext context = new VelocityContext();

  Writer writer = new StringWriter();
  template.merge(context, writer);

  System.out.println(writer);
  }
}

UseMacro.vm
#macro(add $list)
#set($total=0)
#foreach($item in $list)
$item
#set($total =$total+$item)
#end
--------------
total = $total
#end

#set ($list = [122])
#add($list)

Output:
1
2
2
--------------
total =  5

Download code