I'm learning Spring MVC and while in process I came across this problem:
// http://localhost:8080/todo-list/welcomeWithParam?user=Stefan
#GetMapping("welcomeWithParam")
public String welcome91(#RequestParam String user, Model model) {
model.addAttribute("helloThroughParam", demoService.getHelloMessage(user));
return "welcome-with-model";
}
// http://localhost:8080/todo-list/welcomeWithParam?user=Stefan&age=31
#GetMapping("welcomeWithParam")
public String welcome92(#RequestParam String user, #RequestParam int age, Model model) {
model.addAttribute("helloThroughParam", demoService.getHelloMessage(user));
model.addAttribute("age", age);
return "welcome-with-model";
}
I'm getting this error:
Caused by: java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'demoController' method
academy.learnprogramming.controller.DemoController#welcome92(String, int, Model)
to {GET [/welcomeWithParam]}: There is already 'demoController' bean method
academy.learnprogramming.controller.DemoController#welcome91(String, Model) mapped.
So, Spring is telling me we cant have two GET mappings with same URL but different number/type of parameters?
If I change value of one of #GetMapping("") values, it works fine.
Something like this:
#RequestMapping(value = "/welcomeWithParam", params = "user")
public String welcome91(#RequestParam String user, Model model) {
// ...
}
#RequestMapping(value = "/welcomeWithParam", params = {"user","age"})
public ModelAndView welcome92(#RequestParam String user, #RequestParam int age, Model model) {
// ...
}
Related
I am using #RestControllers with an application where all requests are POST requests ... As I learned from this post , you can't map individual post parameters to individual method arguments, rather you need to wrap all the parameters in an object and then use this object as a method parameter annotated with #RequestBody thus
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestParam(value="idNumber") String idNumber , #RequestParam(value="applicationId") String applicationId) {
return customerService.requestOTP(idNumber, applicationId);
will not work with a POST request of body {"idNumber":"345","applicationId":"64536"}
MY issue is that I have A LOT of POST requests , each with only one or two parameters, It will be tedious to create all these objects just to receive the requests inside ... so is there any other way similar to the way where get request parameters (URL parameters) are handled ?
Yes there are two ways -
first - the way you are doing just you need to do is append these parameter with url, no need to give them in body.
url will be like - baseurl+/requestotp?idNumber=123&applicationId=123
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestParam(value="idNumber") String idNumber , #RequestParam(value="applicationId") String applicationId) {
return customerService.requestOTP(idNumber, applicationId);
second- you can use map as follows
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody Map<String,Object> body) {
return customerService.requestOTP(body.get("idNumber").toString(), body.get("applicationId").toString());
I have change your code please check it
DTO Class
public class DTO1 {
private String idNumber;
private String applicationId;
public String getIdNumber() {
return idNumber;
}
public void setIdNumber(String idNumber) {
this.idNumber = idNumber;
}
public String getApplicationId() {
return applicationId;
}
public void setApplicationId(String applicationId) {
this.applicationId = applicationId;
}
}
Rest Controller Method
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody DTO1 dto){
System.out.println(dto.getApplicationId()+" (------) "+dto.getIdNumber());
return "";
}
Request Type -- application/json
{"idNumber":"345","applicationId":"64536"}
OR
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody String dto){
System.out.println(dto);
return "";
}
I have my controller-A class like this:
#PostMapping("/otp")
public String otpSubmit(#RequestParam("token") String token, HttpSession session, Model model) throws IOException {
Long enrollment = (Long) session.getAttribute("enrollment");
BaseResponse otpResponse = otpRestClient.validateOTP(enrollment, token);
if(otpResponse.getCode().equals("1020")) {
model.addAttribute("object", otpResponse.getPayload());
return "redirect:/password";
}
model.addAttribute("errorCode", otpResponse.getCode());
model.addAttribute("errorMessage", otpResponse.getMessage());
return "/otp";
}
What I want is simple (I think) pass the model.addAttribute("object", otpResponse.getPayload()); to controller-B class so I can access that data in the other view.
How can I inject this into controller-B class?.
By adding redirectAttributes we can pass model data
Here is the Controller one.
public String controlMapping1(
#ModelAttribute("mapping1Form") final Model model,
final RedirectAttributes redirectAttributes) {
redirectAttributes.addFlashAttribute("mapping1Form", model);
return "redirect:mapping2";
}
Here is Controller2
public String controlMapping2(
#ModelAttribute("mapping1Form") final Model model) {
model.addAttribute("transformationForm", model);
return "view_name";
}
you can save this "Object o = otpResponse.getPayload()" object in a global variable so later you can access it from any controller.
I'm new with Spring Boot and I have difficult to understand how can I pass data. For example:
I want pass those data to my server:
{
"code", 1,
"name": "C01"
}
So I have create always a custom Object with code and name as attributes to have this http post api?
#RequestMapping(value = "/new/", method = RequestMethod.POST)
public ResponseEntity<?> createOrder(#RequestBody CustomObject customObject){
...
}
Another solution I see that can be this but I can't pass numbers (int code), right?
#RequestMapping(value = "/new/{code}/{name}", method = RequestMethod.POST)
public ResponseEntity<?> createOrder(#PathVariable("code") int code, #PathVariable("name") String name) {
...
}
Kind regards :)
You can pass code and name as PathVariables just like in your example:
#RequestMapping(value = "/new/{code}/{name}")
public ResponseEntity<?> createOrder(#PathVariable("code") int code, #PathVariable("name") String name) {
...
}
A PathVariable can be an int or a String or a long or a Date, according to the docs:
A #PathVariable argument can be of any simple type such as int, long, Date, etc. Spring automatically converts to the appropriate type or throws a TypeMismatchException if it fails to do so.
You could also define a PathVariable of type Map<String, Object> like this:
#RequestMapping(value = "/new/{code}/{name}")
public ResponseEntity<?> createOrder(#PathVariable("map") Map<String, Object> map) {
Integer code = (Integer) map.get("code");
String name = (String) map.get("name");
...
}
You could even use #RequestParam and supply the data in the form of URL query parameters.
So, there are numerous ways in which data can be passed to a Spring MVC controller (more details in the docs) but I think the convention for posting complex data (by "complex" I mean more than a single piece of state) is to define a request body which contains a serialised form of that complex state i.e. what you showed in the first example in your queston:
#RequestMapping(value = "/new/", method = RequestMethod.POST)
public ResponseEntity<?> createOrder(#RequestBody CustomObject customObject){
...
}
If this question is about RESTful best practice, since you are developing webservice for creating an Order object, this is how I would design it
Order.java
public class Order {
private Integer code;
private String name;
public Integer getCode() {
return code;
}
public void setCode(final Integer code) {
this.code = code;
}
public String getName() {
return name;
}
public void setName(final String name) {
this.name = name;
}
}
Controller
#RequestMapping(value = "/orders", method = RequestMethod.POST)
#ResponseStatus(HttpStatus.CREATED)
public ResponseEntity<Order> createOrder(#Valid #RequestBody Order order){
...
}
Technically, you can do many things to achieve the same thing, but that will not be a RESTful service, it will be an RPC at best.
I have next working code in my SpringMVC controller:
#RequestMapping(value = "/register", method = RequestMethod.GET)
public void registerForm(Model model) {
model.addAttribute("registerInfo", new UserRegistrationForm());
}
#RequestMapping(value = "/reg", method = RequestMethod.POST)
public String create(
#Valid #ModelAttribute("registerInfo") UserRegistrationForm userRegistrationForm,
BindingResult result) {
if (result.hasErrors()) {
return "register";
}
userService.addUser(userRegistrationForm);
return "redirect:/";
}
In short create method try to validate UserRegistrationForm. If form has errors, it leaves user on the same page with filled form fields where error message will be shown.
Now I need to apply the same behaviour to another page, but here I have a problem:
#RequestMapping(value = "/buy/{buyId}", method = RequestMethod.GET)
public String buyGet(HttpServletRequest request, Model model, #PathVariable long buyId) {
model.addAttribute("buyForm", new BuyForm());
return "/buy";
}
#RequestMapping(value = "/buy/{buyId}", method = RequestMethod.POST)
public String buyPost(#PathVariable long buyId,
#Valid #ModelAttribute("buyForm") BuyForm buyForm,
BindingResult result) {
if (result.hasErrors()) {
return "/buy/" + buyId;
}
buyForm.setId(buyId);
buyService.buy(buyForm);
return "redirect:/show/" + buyId;
}
I faced with issue of dynamic url. Now if form has errors I should specify the same page template to stay on current page, but also I should pass buyId as a path variable. Where are a conflict in this two requirements. If I leave this code as is, I get an error (I'm using Thymeleaf as a template processor):
Error resolving template "/buy/3", template might not exist or might not be accessible by any of the configured Template Resolvers
I can write something like return "redirect:/buy/" + buyId, but in this case I lose all data and errors of form object.
What should I do to implement in buyPost method the same behaviour as in create method?
I tried the solution metioned in this post at this weekend, but it doesn't work for BindingResult.
The code below works but not perfect.
#ModelAttribute("command")
public PlaceOrderCommand command() {
return new PlaceOrderCommand();
}
#RequestMapping(value = "/placeOrder", method = RequestMethod.GET)
public String placeOrder(
#ModelAttribute("command") PlaceOrderCommand command,
ModelMap modelMap) {
modelMap.put(BindingResult.MODEL_KEY_PREFIX + "command",
modelMap.get("errors"));
return "placeOrder";
}
#RequestMapping(value = "/placeOrder", method = RequestMethod.POST)
public String placeOrder(
#Valid #ModelAttribute("command") PlaceOrderCommand command,
final BindingResult bindingResult, Model model,
final RedirectAttributes redirectAttributes) {
if (bindingResult.hasErrors()) {
redirectAttributes.addFlashAttribute("errors", bindingResult);
//it doesn't work when passing this
//redirectAttributes.addFlashAttribute(BindingResult.MODEL_KEY_PREFIX + "command", bindingResult);
redirectAttributes.addFlashAttribute("command", command);
return "redirect:/booking/placeOrder";
}
......
}
*I'm using Hibernate Validator APIs to validate my beans. To preserve form data along with displaying error messages, you need to do these 3 things:
Annotate your bean (eg. #NotEmpty, #Pattern, #Length, #Email etc.)
Inside controller:
#Controller
public class RegistrationController {
#Autowired
private RegistrationService registrationService;
#RequestMapping(value="register.htm", method=RequestMethod.GET, params="new")
public String showRegistrationForm(Model model) {
if (!model.containsAttribute("employee")) {
model.addAttribute("employee", new Employee());
}
return "form/registration";
}
#RequestMapping(value="register.htm", method=RequestMethod.POST)
public String register(#Valid #ModelAttribute("employee") Employee employee, BindingResult bindingResult, RedirectAttributes redirectAttributes) {
if (bindingResult.hasErrors()) {
redirectAttributes.addFlashAttribute("org.springframework.validation.BindingResult.employee", bindingResult);
redirectAttributes.addFlashAttribute("employee", employee);
return "redirect:register.htm?new";
}
registrationService.save(employee);
return "workspace";
}
// ....
}
Update your view/jsp to hold error messages:
This article can surely be helpful.
You can change your POST implementation to this:
#RequestMapping(value = "/buy/{buyId}", method = RequestMethod.POST)
public String buyPost(#PathVariable long buyId,
#Valid #ModelAttribute("buyForm") BuyForm buyForm,
BindingResult result) {
buyForm.setId(buyId); // important to do this also in the error case, otherwise,
// if the validation fails multiple times it will not work.
if (result.hasErrors()) {
byForm.setId(buyId);
return "/buy/{buyId}";
}
buyService.buy(buyForm);
return "redirect:/show/{buyId}";
}
Optionally, you can also annotate the method with #PostMapping("/buy/{buyId}") if you use Spring 4.3 or higher.
I have scenario where one url "serachUser" may come with two different value (request parameter) userId or UserName.
so for this I have created two methods
public String searchUserById(#RequestParam long userID, Model model)
public ModelAndView searchUserByName(#RequestParam String userName)
But i am getting Ambiguous mapping found exception. Can Spring handle this situation?
You can use the params parameter to filter by HTTP parameters. In your case it would be something like:
#RequestMapping(value = "/searchUser", params = "userID")
public String searchUserById(#RequestParam long userID, Model model) {
// ...
}
#RequestMapping(value = "/searchUser", params = "userName")
public ModelAndView searchUserByName(#RequestParam String userName) {
// ...
}
Any way incase of request param null is allowed if you don't pass any value it will be null then you can write your coad like:
#RequestMapping(value = "/searchUser", params = {"userID","userName"})
public String searchUserById(#RequestParam long userID,#RequestParam String
userName,
Model model) {
if(userID != null){
//..
}else{
// ...
}