java工具类-接受请求参数，并利用反射调用方法

public String a(HttpServletRequest request,HttpServletResponse response) throws JSONException, IOException, ParseException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{
        response.addHeader( "Access-Control-Allow-Origin", "*" );
        response.addHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
        response.addHeader("Access-Control-Allow-Headers", "Content-Type, Authorization, Accept,X-Requested-With");
        String reqStr=request.getParameter("sendJson");
        
        long startTime = System.currentTimeMillis();
        System.out.println("请求参数---" + reqStr);
        logger.info("请求参数---" + reqStr);
        
        String result = "";
        String transCode = "";
        JSONObject jsObj = net.sf.json.JSONObject.fromObject(reqStr);
        net.sf.json.JSONObject head = net.sf.json.JSONObject.fromObject(jsObj.getJSONObject("head"));
        net.sf.json.JSONObject body = net.sf.json.JSONObject.fromObject(jsObj.getJSONObject("body"));
        
        if(head.containsKey("transcode")){
            transCode = head.getString("transcode");
        }else{
            logger.info("交易码不存在！");
            JSONObject resp = new JSONObject();
            resp.put("code", "9999");
            resp.put("message", "交易码不存在");
            result = resp.toString();
            return result;
        }
        
        net.sf.json.JSONObject obj = GetResultByTransCode.getResult(transCode);
        try {
            
            ApplicationContext appContext = ContextLoader.getCurrentWebApplicationContext();
            Object serviceObject = appContext.getBean(obj.getString("serviceName"));
            Method methodName = serviceObject.getClass().getMethod(obj.getString("methodName"), JSONObject.class);
            result = (String) methodName.invoke(serviceObject, body);
            
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        }
        
        return result;
    }