struts2中action实现ModelDriven后无法返回json的解决方法

public class DeviceAction extends AbstractAction implements ModelDriven {
    private static Log log = LogFactory.getLog(DeviceAction.class);
    private Device device=new Device(); //只能json化 模型驱动的bean
    private String result; //无法返回reslut的json值

    
    public String getResult(){
        return result;
    }
    public void setResult(String result){
        this.result=result
    }
    public DeviceDTO getModel() {
        return device;
    }
    public Device getDevice() {
        return device;
    }
    public void setDevice(Device device) {
        this.device = device;
    }
}            

xml配置:

            
            
                
                    resultCode
                
            
        

解决办法:

            
            
                action
                
                    resultCode