ActionForm and Dynaform

[arfatkhan]

Hi Everybody,

What is the difference between ActionForm and DynaFrom.

[tommy]

f you are using actionform then you should specify the getter and setter for each components of presentation (jsp ) in to FormBean file.So it is some what complicated one to specify each component for setter and header. To avoid this method we are having DynoActionForm.In struts-config.xml file we can specify the properties.

[Swamipsn]

Hi,

ActionForm is a normal FormBean which we have to write a java bean code
using traditional getter() & setter() and need to compile. After the rapid evolution of struts many struts developers feels that writing a java ActionFormfor every form is a tedious task. So DynaActionForm was introduced in the case of DynaActionForm we no need to write any ActionForm with native java bean code.DynaActionForm is too easy to use!!

[arfatkhan]

Hi,

I am not clear with, please explain me with a simple example.

Thanks.

[leonard]

Action form example

Code:

public class AddressForm extends ActionForm
{
  private String name=null;
  private String address=null;
  private String emailAddress=null;

  public void setName(String name){
    this.name=name;
  }

  public String getName(){
    return this.name;
  }

  public void setAddress(String address){
    this.address=address;
  }

  public String getAddress(){
    return this.address;
  }


  public void setEmailAddress(String emailAddress){
    this.emailAddress=emailAddress;
  }

  public String getEmailAddress(){
    return this.emailAddress;
  }

If you pay attention in action form you have to write the set and get of every attribute

AddressAction.java

Code:

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class AddressAction extends Action
{
  public ActionForward execute(
    ActionMapping mapping,
    ActionForm form,
    HttpServletRequest request,
    HttpServletResponse response) throws Exception{
      return mapping.findForward("success");
  }
}

Now, Dynaform

Code:

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.DynaActionForm;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.action.ActionMessage;


public class AddressDynaAction extends Action
{
  public ActionForward execute(
    ActionMapping mapping,
    ActionForm form,
    HttpServletRequest request,
    HttpServletResponse response) throws Exception{

    DynaActionForm addressForm = (DynaActionForm)form;

    //Create object of ActionMesssages
        ActionMessages errors = new ActionMessages();
    //Check and collect errors
        if(((String)addressForm.get("name")).equals("")) {
         errors.add("name",new ActionMessage("error.name.required"));
        }

        if(((String)addressForm.get("address")).equals("")) {
         errors.add("address",new ActionMessage("error.address.required"));
        }

        if(((String)addressForm.get("email")).equals("")) {
         errors.add("email",new ActionMessage("error.emailaddress.required"));
        }
    //Saves the error
    saveErrors(request,errors);
    //Forward the page
    if(errors.isEmpty()){
    return mapping.findForward("success");
    }else{
    return mapping.findForward("invalid");
    }
  }
}