Ajax

1:Ext.Ajax.request({
    url: 'vm!findKeyContent.action',
    timeout: 60000,
    params: {
        keyId: key_id
    },
    success: function(response){
        text = response.responseText;
        // process server response here
                        //var respText = Ext.JSON.decode(response.responseText);
//alert(respText.name);
    },
                    failure : function(response) { 
                                Ext.Msg.alert("错误", "无法访问后台"); 
                    } 
});

2: //define model 
Ext.define('Vmkey', {
                extend: 'Ext.data.Model',
                fields: [
                {name: 'vmkeyId', type: 'int'},
                    {name: 'keyname',  type: 'string'},
                    {name: 'href', type: 'string'},
                    {name: 'fingerprint',  type: 'string'},
                    {name: 'pemKey',  type: 'string'},
                    {name: 'status',  type: 'string'},
                    {name: 'description',  type: 'string'},
                    {name: 'clouduserId',  type: 'int'}
                ]
            });
       //loading data
       var myStore = Ext.create('Ext.data.Store', {
        model: 'Vmkey',
        proxy: {
            type: 'ajax',
            url : 'vm!key.action',
            reader: {
                type: 'json',
                root: 'vmkeys'
            }
        }
    });