java code for Calculation Based on Model

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;

public class ProductList {

public static void main(String[] args) throws Exception {
Velocity.init();

Template t = Velocity.getTemplate("./src/model.vm");

VelocityContext ctx = new VelocityContext();

Collection products = new ArrayList();
products.add(new Product("Product 1", 142.919));
products.add(new Product("Product 2", 133.199));
products.add(new Product("Product 3", 112.991));

ProductListModel model = new ProductListModel(products);
ctx.put("model", model);

Writer writer = new StringWriter();
t.merge(ctx, writer);

System.out.println(writer);
}
}
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import java.util.Collection;
import java.util.Iterator;

public class ProductListModel {

private Collection productList = null;

private double totalPrice = Double.MIN_VALUE;

public ProductListModel(Collection aProductList) {
productList = aProductList;
}

public Collection getProductList() {
return productList;
}

public void setProductList(Collection aProductList) {
productList = aProductList;
}

public double getTotalPrice() {
if (totalPrice == Double.MIN_VALUE) {

totalPrice = 0;
Iterator itr = productList.iterator();

while (itr.hasNext()) {
Product p = (Product) itr.next();
totalPrice += p.getPrice();
}
}

return totalPrice;
}
}

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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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#foreach($product in $model.productList)
$product.Name $$product.Price
#end