Spring MVC. Question about visions solution / Design Question

开发者 https://www.devze.com 2023-02-10 13:16 出处：网络

[spring 3.0.5] MVC I have on class like that: public class Address { private String street; private String city;

[spring 3.0.5] MVC

I have on class like that:

public class Address {

  private String street;
  private String city;

  public String getStreet() {
     return this.street;
  }

  public void setStreet(String street) {
     this.street = street;
  }

  public String getC开发者_JAVA百科ity() {
     return this.city;
  }

  public void setCity(String city) {
    this.city = city;
  }
}

My function is to rely on the possibility of adding an infinite number of addresses on the site (JSP with spring and form tag). Can somebody give a skeleton of such functionality in the controller?

Your question is a little unclear. The answer is twofold:

Displaying a list of addresses

 @Controller
 public class SomeController {

     @RequestMapping("/somepage.jsp ") 
     public String somePage(HttpServletRequest request, ModelMap model) {
         List<Address> addresses = ....
         // We can now access the key "addresses" in our jsp
         model.put("addresses", addresses);
         return "/WEB-INF/jsp/somepage.jsp";
     }
 }

In your jsp page, you can display the list of addresses using e.g., the core jstl lib, here noted using the prefix c.

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html> 
   ...

    <c:forEach items="${addresses}" var="addr">
        City:   ${addr.city}   <br/>
        Street: ${addr.street}
    </c:forEach>

   ....
</html>

Submitting addresses

If you're looking to submit an undefined number of addresses, that's a little more tricky. What you could do is create a javasript form template which upon a button press or so creates two additional form fields. Ensure each form field will get a unique name, e.g., :

 <input type="text" name="street_1" />
 <input type="text" name="city_1" />

 <input type="text" name="street_2" />
 <input type="text" name="city_2" />

 ....

Then you can iterate the fields using request.getParameterMap(), where you construct your address options based on matching names (e.g., street_1 should be associated with city_1 and so forth).

[EDIT] To give you an idea of what the javascript could look like, I give you this from the top of my head (note I haven't tested this code, it's there to give you an idea of what it might look like).

var i = 0; // initialize to how many addresses you initially display
function addAddress() {
    var form = document.getElementById('form');
    var html = '<input type="text" name="street_' + i + '" />' + 
               '<input type="text" name="city_'   + i + '" />';
    form.innerHTML += html;
    i++;
}

Then call the javascript when pressing a button:

<input type="button" onClick="addAddress();" value="add address" />

If you decided to use e.g., jQuery this would be even easier. E.g.,

var i  = 0:
$("#addbtn").click(function() {
    $("#someId").append(
         '<input type="text" name="street_' + i + '" />' + 
         '<input type="text" name="city_'   + i + '" />');
    i++;
});