title: extjs and struts integration
body: <p>i'm trying to use struts2-json-plugin to integrate struts actions and extjs.
  i want to send json from extjs to struts2 action. this json contains all fields of my bean (UserEntity). but the setter of the action class does not call.
  here is my code:</p>
  
  <p>UserAction.java</p>
  
  <pre><code>public class UserAction extends BaseAction {
  
        private UserEntity userEntity = new UserEntity();
  
        public UserEntity getUserEntity() {
             return userEntity;
        }
  
        public void setUserEntity(UserEntity userEntity) {
             this.userEntity = userEntity;
        }
  
        ...
  }
  </code></pre>
  
  <p>struts.xml</p>
  
  <pre><code>     &lt;?xml version="1.0" encoding="UTF-8" ?&gt;
  &lt;!DOCTYPE struts PUBLIC
          "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
          "http://struts.apache.org/dtds/struts-2.0.dtd"&gt;
  
  &lt;struts&gt;
      &lt;package name="default" namespace="/" extends="struts-default,json-default"&gt;
  
          &lt;action name="saveOrUpdateUserAction" class="ir.emad.action.UserAction" method="saveOrUpdateUser"&gt;
              &lt;result name="success" type="json"&gt;
                  &lt;param name="root"&gt;userEntity&lt;/param&gt;
              &lt;/result&gt;
          &lt;/action&gt;
  
      &lt;/package&gt;
  
  &lt;/struts&gt;
  </code></pre>
  
  <p>and my UserStore.js</p>
  
  <pre><code>    Ext.define('AM.store.UserStore', {
      extend: 'Ext.data.Store',
      model: 'AM.model.UserModel',
      autoLoad: true,
  
      proxy: {
          type: 'ajax',
          api: {
              read: 'listAllUsersAction',
              update: 'saveOrUpdateUserAction'
          },
          reader: {
              type: 'json',
              root: 'users',
              successProperty: 'success'
          },
          writer: {
              type: 'json',
              root: 'userEntity',
              successProperty: 'success',
              encode: true
          },
          contentType: 'application/json'
  
      }
  });
  </code></pre>
  
  <p>my problem is the setter of userEntity never called.if i change the setter to below code every thing is fine. but i want to set the json object directly into UserEntity bean.</p>
  
  <pre><code>public void setUserEntity(String userEntity){
     ...
  }
  </code></pre>
  
  <p>any help will be appreciated
  Thanks in advance</p>