• 在我们的代码中，Ext JS页面的参数被传递到Spring 3控制器，在那里我们有业务逻辑。然后在控制器中，使用getWriter设置响应对象。在Ext JS页面中检索写入和响应。问题：在解码响应时，Firebug显示了一个使用Ext.util.JSON.decode的错误，所以我们不得不使用Ext.decode来解码来自服务器的响应。但是Ext.decode给出了一个值：object对象。我需要将其转换为String或格式。控制器代码：

import java.io.IOException;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
@RequestMapping
public class SampleController {

    @RequestMapping(value = "/login.htm",method = RequestMethod.POST)
     @ResponseBody
     public void validateCredentials(@RequestParam("user") String user,
            @RequestParam("password") String password,HttpServletResponse response) {
        boolean flag = false;
        String resultString = null;



        try {
            response.setContentType("application/json");
            response.setHeader("Content-Type", "text/html, charset=utf-8");

            if (user.equals(password)) {

                flag = true;
                resultString = "{success:true}";
            } else {

                flag = false;
                resultString = "{success:false}";
            }

            response.getWriter().write(resultString);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}
Ext JS Login form :
Ext.onReady(function(){

    function submit(button,event){

               var uname=Ext.getCmp('user').getValue();
             alert("1"+uname);
                var passWord=Ext.getCmp('password').getValue();

             Ext.Ajax.request({
                   url: 'login.htm',
                   method :'POST',

                   params: {
                       user:uname,
                       password:passWord
                    },
                   success: function(result,request) {
                      var jresp = Ext.JSON.decode(result.responseText); 
//Ext.JSON.decode stores object Object in jresp. Our requirement is converting jresp to String or boolean
                      console.log('Success'+jresp); 


                   },
                   failure: function(response, request) {
                       var jresp = Ext.JSON.decode(result.responseText);
                       console.log(jresp.error);
                      console.log('server-side failure with status code 8 ' + response.status);
                   }
                });



           }



     var myform = new Ext.form.FormPanel({
            title:'Login form',
            frame:true,
            width:400,
            height: 250, 

            url:'login.htm',
            method:'POST',
            renderTo:'div1',
            items:[
                   {
                       xtype:'textfield',
                       fieldLabel:'user',
                       inputType:'user',
                       allowBlank:false,
                       minLengthText:'3',
                       id:'user',
                       name:'user'
                   },
                   {
                       xtype:'textfield',
                       fieldLabel:'password',
                       inputType:'password',
                       allowBlank:false,
                       minLengthText:'3',
                       id:'password',
                       name:'password'
                   }
                   ],
                   buttonAlign:'center',
                   buttons:[
                            {
                                text:'reset',handler:function(){myform.getForm().reset();}
                            },
                            {

                                text:'Login',
                                handler: submit
                            }

                            ]       

                   });




});