我应该在JavaServlet中正确使用PRG模式，还是应该做其他事情？
我有这个控制器，在Get方法中我使用请求分派器，在Post中我使用重定向我应该在JavaServlet中正确使用PRG模式，还是应该做其他事情？,java,post,servlets,design-patterns,get,Java,Post,Servlets,Design Patterns,Get,我有这个控制器，在Get方法中我使用请求分派器，在Post中我使用重定向 @WebServlet(name = "ControllerOrder", value = "/User/Order") public class ControllerOrder extends HttpServlet { private static final Logger LOGGER = Logger.getLogger(ControllerOrder.class);
@WebServlet(name = "ControllerOrder", value = "/User/Order")
public class ControllerOrder extends HttpServlet {
private static final Logger LOGGER = Logger.getLogger(ControllerOrder.class);
private MySQLCarCategoryDao categoryDao;
@Override
public void init() throws ServletException {
super.init();
MySQLDAOFactory dao = (MySQLDAOFactory) getServletContext().getAttribute("MySQLFactory");
categoryDao = (MySQLCarCategoryDao) dao.getCarCategoryDao();
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ImageManager manager = ImageManager.getInstance();
List<CarCategory> carCategories = categoryDao.findExistingCarC();
List<ToggleButton> buttons = IntStream.range(0, carCategories.size())
.mapToObj(i -> {
ToggleButton button = new ToggleButton();
button.setIcon("img:data:image/png;base64," + manager.getBase64String(manager.imageToByte(carCategories.get(i).getCarCategoryImage())));
button.setValue(carCategories.get(i).getCarCategory());
button.setSlot(i+1+"");
return button;
})
.collect(Collectors.toList());
ObjectMapper mapper = new ObjectMapper();
try {
request.setAttribute("CarCategories",carCategories);
request.setAttribute("CarCategoriesButtons",mapper.writeValueAsString(buttons));
} catch (JsonProcessingException e) {
LOGGER.error(e);
}
request.getRequestDispatcher("/WEB-INF/view/order.jsp").forward(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession();
String login = (String) session.getAttribute("Login");
String userAddress = request.getParameter("userAddress");
String userDestination = request.getParameter("userDestination");
String[] stingNumbers = request.getParameterValues("numOfPas");
String[] categories = request.getParameterValues("categories");
if(stingNumbers != null && stingNumbers.length > 0&&categories != null && categories.length > 0) {
OrdersMaker maker = new OrdersMaker();
String message = maker.makeOrder(stingNumbers,categories,userAddress,userDestination,login);
if(message.startsWith("false")){
response.sendRedirect(request.getContextPath() + "/User/Order?NotAvailable=" + message);
return;
}
response.sendRedirect(request.getContextPath() + "/User/Order?takenTime=" + message);
}
}
}
@WebServlet（name=“ControllerOrder”，value=“/User/Order”）
公共类ControllerOrder扩展了HttpServlet{
私有静态最终记录器=Logger.getLogger（ControllerOrder.class）；
私有MySQLCarCategoryDao categoryDao；
@凌驾
public void init（）引发ServletException{
super.init（）；
MySQLDAOFactory dao=（MySQLDAOFactory）getServletContext（）.getAttribute（“MySQLFactory”）；
categoryDao=（MySQLCarCategoryDao）dao.getCarCategoryDao（）；
}
@凌驾
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
ImageManager=ImageManager.getInstance（）；
List carCategories=categoryDao.findExistingCarC（）；
列表按钮=IntStream.range（0，carCategories.size（））
.mapToObj（i->{
ToggleButton=新的ToggleButton（）；
setIcon（“img:data:image/png；base64，”+manager.getBase64String（manager.imageToByte（carCategories.get（i.getCarCategoryImage（））））；
setValue（carCategories.get（i）.getcarcategority（））；
按钮。设置批次（i+1+“”）；
返回按钮；
})
.collect（Collectors.toList（））；
ObjectMapper mapper=新的ObjectMapper（）；
试一试{
request.setAttribute（“CarCategories”，CarCategories）；
setAttribute（“CarCategoriesButtons”，mapper.writeValueAsString（buttons））；
}捕获（JsonProcessingException e）{
错误（e）；
}
request.getRequestDispatcher（“/WEB-INF/view/order.jsp”）.forward（请求，响应）；
}
@凌驾
受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException{
HttpSession session=request.getSession（）；
String login=（String）session.getAttribute（“login”）；
字符串userAddress=request.getParameter（“userAddress”）；
字符串userDestination=request.getParameter（“userDestination”）；
字符串[]stingNumbers=request.getParameterValues（“numofas”）；
String[]categories=request.getParameterValues（“categories”）；
如果（stingNumbers！=null&&stingNumbers.length>0&&categories！=null&&categories.length>0）{
OrdersMaker maker=新的OrdersMaker（）；
String message=maker.makeOrder（StingNumber、categories、userAddress、userDestination、login）；
if（message.startsWith（“false”））{
response.sendRedirect（request.getContextPath（）+“/User/Order？NotAvailable=“+message”）；
返回；
}
response.sendRedirect（request.getContextPath（）+“/User/Order？takenTime=“+message”）；
}
}
}