Spring 3 mvc and tiles - populate *.jsp page with some data before

Question 1

If you're intending to hold a list of records in the attribute rowsFromDb, then you should populate this in your controller and set the list in the model. Then in data.jsp you can iterate this list using the <c:forEach> tag. For example (a madeup example to illustrate the point):

Controller

@RequestMapping("/listRows")
public ModelAndView listRows() {
    List<Row> rows = myRepository.getAllRows(); // Hide the DB query code behind a repository
    ModelAndView modelAndView = new ModelAndView("/");
    modelAndView.addObject("rowsFromDb", rows); // Set the data in the model
    return modelAndView;
}

data.jsp

<c:forEach items="${rowsFromDb}" var="row">
    <c:out value="${row.someProperty}"/>
<c:forEach>

You should avoid doing any database query directly in the JSP itself (and avoid any Java in the JSP where possible). The JSP should just deal with rendering the data it is given by the controller.

Question 2

You can use Tiles org.apache.tiles.preparer.ViewPreparer for this purpose.

Create a new class that implements org.apache.tiles.preparer.ViewPreparer in your source folder. For example:

package com.example.tiles;
import ...

public class MyMenuPreparer implements ViewPreparer {

   @Override
   public void execute(TilesRequestContext tilesContext, AttributeContext attributeContext) {

      // The code here will be executed before rendering the view.      
      // For example, you can check for security (Spring Security)
      // or you can execute query to database to retrieve list of menus

      ...

      // You can add result to your request scope:
      tilesContext.getRequestScope().put("rowsFromDb", result);

      // To retrieve the value in a JSP:
      // <c:forEach var="item" items="${rowsFromDb}">
      //    ...
      // </c:forEach>


      // Or you can add it as attribute for the view
      attributeContext.putAttribute("rowsFromDb", result, true);

   }

}

In your Tiles definition, you must add preparer attribute in the definition, such as:

<definition name="menu" 
    template="/WEB-INF/layouts/menu.jspx" 
    preparer="com.example.tiles.MyMenuPreparer">
    ...
</definition>

Question 3

Founded solution. Thanks all for helped me!

Code in controller:

...

@RequestMapping(value={"/"},method=RequestMethod.GET)
        public String home(HttpServletRequest request,Model model){
            JdbcTemplate jdbc=new JdbcTemplate(dataSource(request));

            String sql="SELECT * FROM products ORDER BY id ASC";        
            List<Product>products=jdbc.query(sql,new ProductMapper());

            sql="SELECT * FROM category ORDER BY (id)";
            List<Category>categories=jdbc.query(sql, new CategoryMapper());

            model.addAttribute("products", products);
            model.addAttribute("categories",categories);

            return "/";
        }

        ...

Code in *.jsp page

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<c:forEach var="p" items="${products}"> 
    <div id="dataRow">
        <form:form method="POST" action="/shoppingCart">        
            <div id="dataPicture"><img src="<%=request.getContextPath()%>/images/hard_diskovi/${p.getPicture()}"/></div>
            <div id="dataName">${p.getName()}</div>
            <div id="dataPrice">
                Price: 
                <fmt:formatNumber minFractionDigits="2" maxFractionDigits="2" value="${p.getPrice()}"/> 
                euro
            </div>
            <input type="hidden" value="${p.getId()}"/>
            <input id="dataSubmit" type="submit" value="add"/>
        </form:form>
    </div>  
</c:forEach>

Conclusion: data for page that isn't a template it need to send from controller and on the target page use 'jsp' or 'jstl' or ...