用easyui时出现的有关问题 初学者一枚 需要帮助

package com.ly.action;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import net.sf.json.JSONObject;

import com.ly.model.Products;
import com.ly.model.User;
import com.ly.service.ProductsService;
import com.ly.service.UserService;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;


public class LoginAction extends ActionSupport {

	private static final long serialVersionUID = 1L;
	private String username;
	private String password;
	private JSONObject easyJson;
	private UserService userService;
	private ProductsService productsService;

	@Override
	public String execute() throws Exception {
		if(username!=null && username.length()>0 &&
				password!=null && password.length()>0){
			User u=userService.find(username);
			if(u==null){
				this.addFieldError(username, "用户名或密码错误");
				return "input";
			}
			if(u.getPassword().equals(password)){
				
				ActionContext.getContext().getSession().put("NAME", u.getName());
				List<Products> products=productsService.find();
				Map<String, Object> map = new HashMap<String, Object>();
				map.put("total", products.size());
				map.put("rows", products);
				easyJson = JSONObject.fromObject(map);
				ActionContext.getContext().getSession().put("PRODUCTS", products);
				return "ok";
			}else{
				this.addFieldError(password, "用户名或密码错误");
				return "input";
			}	
		}else{
			return "input";
		}
	}

	
	public JSONObject getEasyJson() {
		return easyJson;
	}


	public void setEasyJson(JSONObject easyJson) {
		this.easyJson = easyJson;
	}


	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public UserService getUserService() {
		return userService;
	}

	public void setUserService(UserService userService) {
		this.userService = userService;
	}

	public ProductsService getProductsService() {
		return productsService;
	}

	public void setProductsService(ProductsService productsService) {
		this.productsService = productsService;
	}

	
	
	
}

$(document).ready(function() {
	$('#tt').datagrid({
		title : 'table',
		iconCls : 'icon-ok',
		nowrap : fasle,
		width:800,
		height:500,
		rownumbers:true,
		url:'project/LoginAction.action',
		idField:'easyJson',
		method:'post',
		columns:[
		    [{title:'products',colspan:10}],
		    [{field:'productID',title:'productID',width:80,align:'center'},
		     {field:'productName',title:'productName',width:80,align:'center'},
		     {field:'supplierID',title:'supplierID',width:80,align:'center'},
		     {field:'categoryID',title:'categoryID',width:80,align:'center'},
		     {field:'quantityPerUnit',title:'quantityPerUnit',width:80,align:'center'},
		     {field:'unitPrice',title:'unitPrice',width:80,align:'center'},
		     {field:'unitsInStock',title:'unitsInStock',width:80,align:'center'},
		     {field:'unitsOnOrder',title:'unitsOnOrder',width:80,align:'center'},
		     {field:'reorderLevel',title:'reorderLevel',width:80,align:'center'},
		     {field:'discontinued',title:'discontinued',width:80,align:'center'},
		     
		     ]
		         ]
	});	

});

	

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC 
"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" 
"http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
	<constant name="struts.local" value="zh_CN" />
	<constant name="struts.devMode" value="false" />
	<package name="project" extends="json-default">
		<action name="loginAction" class="bean_LoginAction">
			<result type="json">
				<param name="root">easyJson</param>
			</result>
			<!-- <result name="ok">welcome.jsp</result>  -->
		</action>

		<!-- <action name="loginAction" class="bean_LoginAction" >