java code for Reference Class method in Mathtool

import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;

import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.tools.generic.MathTool;

public class ProductList {

public static void main(String[] args) throws Exception {
Velocity.init();
Template t = Velocity.getTemplate("./src/calculation.vm");
VelocityContext ctx = new VelocityContext();

Collection products = new ArrayList();
products.add(new Product("Product 1", 112.199));
products.add(new Product("Product 2", 113.991));
products.add(new Product("Product 3", 111.919));
ctx.put("productList", products);

ctx.put("math", new MathTool());
Writer writer = new StringWriter();
t.merge(ctx, writer);

System.out.println(writer);
}
}


public class Product {

private String name;
private double price;

public Product(String aName, double aPrice) {
name = aName;
price = aPrice;
}

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}

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#set($totalPrice = 0)
#foreach($product in $productList)
$product.Name $$product.Price
#set($totalPrice = $math.add($totalPrice, $product.Price))
#end

Total Price: $$totalPrice