Java/Velocity/Calculation

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    $$product.Price
#end
Total Price: $$model.totalPrice

Calculation In Java

import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
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/calculation.vm");
    VelocityContext ctx = new VelocityContext();
    Collection products = new ArrayList();
    products.add(new Product("Product 1", 12.99));
    products.add(new Product("Product 2", 13.99));
    products.add(new Product("Product 3", 11.99));
    ctx.put("productList", products);
    // calculate total
    Iterator itr = products.iterator();
    double total = 0.00;
    while (itr.hasNext()) {
      Product p = (Product) itr.next();
      total += p.getPrice();
    }
    ctx.put("totalPrice", new Double(total));
    Writer writer = new StringWriter();
    t.merge(ctx, writer);
    System.out.println(writer);
  }
}
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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 $productList)
$product.Name    $$product.Price
#end
Total Price: $$totalPrice