I want to make a form in which I can update my entity in my REST application. For example I have a User entity whith username and realname fields.
Do I need in my request method do something like this
#RequestMapping(value = "/admin/user/update", method = RequestMethod.POST)
public String updateHouse(#RequestBody String username, #RequestBody String realname, Model model)
??
I would prefer to make something like this
#RequestMapping(value = "/admin/house/update", method = RequestMethod.POST)
public String updateHouse(#RequestBody User user, Model model)
I mean that I want to send an object not every field. If i`ll have 20 fields in my entity I would have to add 20 params to my method. Thats not to fancy.
I`m using spring form tag
------- UPDATE
thanks for response. below diffrent entity but real case scenario that i`m trying to start
html code
<c:url var="houseUpdateLink" value="/admin/house/update" />
<form:form method="post" commandName="house" action="${houseUpdateLink}">
<form:input path="house.title" />
<input type="submit" value="send" />
</form:form>
controller method
#RequestMapping(value = "/admin/house/update", method = RequestMethod.POST)
public String updateHouse(#RequestBody House house, Model model) {
model.addAttribute("step", 3);
logger.info("test: " + house.getTitle());
return "houseAdmin";
}
and i receive
HTTP Status 415 -
type Status report
message
description The server refused this request because the request entity is in a format not supported by the requested resource for the requested method ().
You don't need #RequestBody here. Spring will automatically bind the form fields to the House class without it, i.e.
#RequestMapping(value = "/admin/house/update", method = RequestMethod.POST)
public String updateHouse(House house, Model model) {
In the Spring form tags, you can probably do user.username, and pass the User object as a param.
Related
I have a form that has 10+ field inputs that will get updated by a user. On submit I need to update the object (by id) and any/all fields that were modified in the form (utilizing Spring Data JPA & Repositories). I believe I can do this by passing the #ModelAttribute as a method argument tied to my object, but I don't quite fully understand this yet. Here's my Controller
#RequestMapping(value = "/saveUser/{id}", method = RequestMethod.POST)
public String saveUser(#ModelAttribute("User") User user, #PathVariable Long id, Model model) {
user = userRepo.findOne(id); //Spring Repository method to find user by ID
// Here is where you'd set all fields of the User object including those modified in the form
model.addAttribute("user", user);
userRepo.save(user); //Updates user in database
return "success";
}
I'm looking for a method that would do the exact same thing as:
user.setName(user.getName());
user.setAddress(user.getAddress));
//etc.
Without explicitly calling each set method (the number of field inputs will grow).
Thanks mates
If you have a form and you´re using ModelAndAttribute you just need to set the id attribute to be send to the Controller
<form:input id="id" path="id"/>
<form:input id="name" path="name"/>
<form:input id="address" path="address"/>
Then in your controller you just need to do what you´re just doing
#RequestMapping(value = "/saveUser/{id}", method = RequestMethod.POST)
public String saveUser(#ModelAttribute("User") User user, #PathVariable Long id, Model model) {
user = userRepo.findOne(id); //Spring Repository method to find user by ID
// Here is where you'd set all fields of the User object including those modified in the form
model.addAttribute("user", user);
userRepo.save(user); //Updates user in database
return "success";
}
BUT, if you´re doing this request by Ajax you will need to load the again the entity User to set the new entity in your form with the new Id.
You can take a look to JQuery load to load the form element again.
Or if the save is done by HTTP Request you must refresh the page after save so you need to return again the ModelAndView with the entity user already update with an id
#RequestMapping(value = "/saveUser/{id}", method = RequestMethod.POST)
public String saveUser(#ModelAttribute("User") User user, #PathVariable Long id, Model model) {
user = userRepo.findOne(id); //Spring Repository method to find user by ID
userRepo.save(user); //Updates user in database
ModelAndView mav = new ModelAndView(yourview);
mav.setObject("user", user);
return mav;
}
I'm following the Spring MVC tutorial here: http://www.tutorialspoint.com/spring/spring_mvc_form_handling_example.htm
and I'm not getting the logic how is the data passed from JSP to Controller.
I think I understand how the data is passed from the Controller to the JSP, but after the user has edited the form on the JSP how is the data passed to the Controller?
In the controller:
public String addStudent(#ModelAttribute("SpringWeb")Student student, ModelMap model)
question:
How the controller knows that from the form on the jsp Student class instance student with name, age and id are passed?
I have this example working. I have altered the example to display a list of students, but I am not able to get the list from JSP to Controller:
#RequestMapping(value = "/student", method = RequestMethod.POST)
public ModelAndView studentSave(#ModelAttribute("listOfStudents") ArrayList<Student> listOfStudents,ModelMap model)
{
ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate) context.getBean("studentJDBCTemplate");
System.out.println("Size of listOfStudents is = " + listOfStudents.size());
...
listOfStudents.size() returns 0.
question: what am i missing here, why I can't get the list from the form on the jsp?
question: How the controller knows that from the form on the jsp
Student class instance student with name, age and id are passed?
When you submit the form you are making an HTTP (typically, POST) request to a given URL. This POST request will contain the values in
the form as request parameters. If you were not using any web framework (e.g. Spring MVC) then you would typically work directly with the Servlet API
to extract and work with these values, particularly the HttpServletRequest object.
http://docs.oracle.com/javaee/6/api/javax/servlet/http/HttpServletRequest.html
You can try this is your application by adding the following (the Spring MVC framework will automatically pass in the request).
public String addStudent(#ModelAttribute Student student, HttpServletRequest request){
for(String key : request.getParameterMap().keySet()){
System.out.println(key + "=" + request.getParameterMap().get(key);
}
}
Now, regardless of the framework you are using the underlying mechanism does not change, the parameters are still sent in the POST request as simple Strings.
The framework however essentially adds an abstraction layer on top of this to prevent you having to write boilerplate to extract and manually work with these
parameters. So, rather than having to do the following:
public String addStudent(HttpServletRequest request){
Student student = new Student();
student.setId(Integer.parseInt(request.getParameter("id"));
student.setName(request.getParameter("name"));
....
}
you let the framework take care of it.
public String addStudent(#ModelAttribute Student student){
}
The #ModelAttribute tells the framework you want the submitted parameters to be bound to a Student instance. On submit, the framework will create a new Student
instance and, by means of reflection, (http://docs.oracle.com/javase/tutorial/reflect/) set the various fields to the corresponding HTTP params.
As for the 2nd part of your question there are numerous examples of how to bind to a Collection. See below for example:
http://viralpatel.net/blogs/spring-mvc-multi-row-submit-java-list/
Generally 'work' is done in the controller, and the results are passed to the JSP simply for display. The JSP renders to the user's browser over HTTP and then the user modifies the page and posts back to the controller.
If you're doing 'work' in the JSP that needs to be passed back to the controller before the page is sent to the user, then you should consider finding a way of doing all that in the controller.
Having said this. The model that you pass to the JSP doesn't have to contain simple objects. You can pass to the JSP an object that has methods on it that performs processing. Then in the JSP you simply call one of the methods on that object.
the controller and jsp are linked together by #ModelAttribute.
example if i want to add a new student i would first link the corresponding jsp page with the student database. like
//setup add new student form
#RequestMapping(value = "/add", method = RequestMethod.GET)
public String setStudentForm(#ModelAttribute("newStudent") Student newStudent){
return "addstudent";
}
this will set up my jsp page. In jsp page i have already declared the colums like firstname, lastname which are linked with my student model.
<form:form modelAttribute="newStudent" class="form-horizontal">
<form:input id="firstName" path="firstName" type="text"/>
<form:input id="lastName" path="lastName" type="text"/>
<input type="submit" id="btnAdd" value ="add"/>
</form>
Like this i created the ling. Now when i press submit button if will land a post request and thus following method in controller will be executed.
#RequestMapping(value = "/add", method = RequestMethod.POST)
public String processStudentForm(Model model, #ModelAttribute("newStudent") #Valid Student newStudent, BindingResult result ){
newStudent.setFirstName("gurpreet");
if(result.hasErrors()){
return "addstudent";
}
studentService.add(newStudent);
model.addAttribute("message", "Added successfully");
return "redirect:/students";
}
I can also make changes in the data like i did newStudent.setFirstName("gurpreet"); before saving the object through studentService
the #RequestMapping url is same but method has changed to POST from GET as submit button have POST submission.
(#ModelAttribute("newStudent") Student newStudent)
associates our view, Model and controller alltogether.
Please correct me if I am wrong.
Both can be used for Data Binding.
The question is when to use #ModelAttribute?
#RequestMapping(value="/owners/{ownerId}/pets/{petId}/edit", method = RequestMethod.POST)
public String processSubmit(#ModelAttribute Pet pet) { }
In addition, when to use #RequestBody?
#RequestMapping(value = "/user/savecontact", method = RequestMethod.POST
public String saveContact(#RequestBody Contact contact){ }
According to my understanding both serves the similar purpose.
Thanks!!
The simplest way for my understanding is, the #ModelAttribute will take a query string. so, all the data are being pass to the server through the url.
As for #RequestBody, all the data will be pass to the server through a full JSON body.
#ModelAttribute is used for binding data from request param (in key value pairs),
but #RequestBody is used for binding data from whole body of the request like POST,PUT.. request types which contains other format like json, xml.
If you want to do file upload, you have to use #ModelAttribute. With #RequestBody, it's not possible. Sample code
#RestController
#RequestMapping(ProductController.BASE_URL)
public class ProductController {
public static final String BASE_URL = "/api/v1/products";
private ProductService productService;
public ProductController(ProductService productService) {
this.productService = productService;
}
#PostMapping
#ResponseStatus(HttpStatus.CREATED)
public ProductDTO createProduct(#Valid #ModelAttribute ProductInput productInput) {
return productService.createProduct(productInput);
}
}
ProductInput class
#Data
public class ProductInput {
#NotEmpty(message = "Please provide a name")
#Size(min = 2, max = 250, message = "Product name should be minimum 2 character and maximum 250 character")
private String name;
#NotEmpty(message = "Please provide a product description")
#Size(min = 2, max = 5000, message = "Product description should be minimum 2 character and maximum 5000 character")
private String details;
#Min(value = 0, message = "Price should not be negative")
private float price;
#Size(min = 1, max = 10, message = "Product should have minimum 1 image and maximum 10 images")
private Set<MultipartFile> images;
}
I find that #RequestBody (also annotating a class as #RestController) is better for AJAX requests where you have complete control over the contents of the request being issued and the contents are sent as either XML or JSON (because of Jackson). This allows the contents to easily create a model object. Conversely, #ModelAttribute seems to be better suited to forms where there is a "command" object backing a form (which may not necessarily be a model object).
You can directly access your "pet" object in view layer, if you use ModelAttribute annotation. Also, you can instantiate this object in a method on your controller to put your model. see this.
ModelAttribute gives you a chance to use this object partial, but with RequestBody, you get all body of request.
I think #ModelAttribute and #RequestBody both are having same use, only difference
is #ModelAttribute use for normal spring MVC and #RequestBody use for REST web service. It is #PathVariable and #PathParam. But in in both the cases we can mix it. we can use #PathVariable in REST and vice versa.
With #ModelAttribute, you pass data in URL params and with #RequestBody you pass it as JSON body. If you're making a REST API then it's better to use #RequestBody. Over most youtube tutorials you might find use of #ModelAttribute - That's simply because they might be demonstrating concepts regarding Spring MVC and are using URL's to pass data.
We need to have the following jsp tag to data bind your entity to the jsp form fields:
The form is from the spring tag library:
The following is the not the full html, but I hope you can relate your self:
<%#taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<form:form action="save" method="post" modelAttribute="patient">
<table>
<tr>
<td>Name</td>
<td>
<form:input path="patient.patient_name" /> <br />
</td>
</tr>
<tr>
<td>Phone</td>
<td>
<form:input path="patient.phone_number" /> <br />
</td>
</tr>
<tr>
<td colspan="2"><button type="submit">Submit</button></td>
</tr>
</table>
</form:form>
The form has to be processed twice , once before rendering the form, during which we need to give the appropriate bean instantiation for the property value modelAttribute="patient".
For this the controller class(at the class defintion level) you need to have #RequestMapping annotation.
You need to have the handler method parameters as follows
#GetMapping("logincreate")
public String handleLoginCreate(#ModelAttribute("login") Login login, Model model)
{
System.out.println(" Inside handleLoginCreate ");
model.addAttribute("login",login);
return "logincreate";
}
Spring will scan all handler methods #ModelAttribute and instantiate it with default constructor of Login class, and call all of its getters and setters (for the jsp binding from form to the "login"). In case of missing any of the following the jsp will not be shown, various exceptions are thrown
getters/setters
default constructor
model.addAttribute("login",login);
class level #RequestMapping
method parameter level #ModelAttribute
Also, the handler method of action in the jsp, the in the above form action="save", also the handler method might look like this:
#PostMapping("save")
public String saveLoginDetails(#ModelAttribute("login") Login login, Model model) {
//write codee to insert record into DB
System.out.println(" Inside save login details ");
System.out.println("The login object is " + login.toString());
System.out.println("The model object contains the login attribute"+ model.getAttribute("login"));
loginService.saveLogin(login);
return "welcome";
}
Important learning is:
Before form is launched, spring should have appropriate annotation to indicate the backing bean of the form, in the above example the "backing bean" or "binding object" is Login login with appropriate handler method's parameter annotation #ModelAttribute("login") Login login
Why isn't my id preserved of the #ModelAttribute? Why do I have to send it as a hidden parameter in my form? Shouldn't spring handle this when using command?
#RequestMapping(value="/{supplierId}", method=RequestMethod.GET)
public String get(#PathVariable Long supplierId, Model model, Principal principal){
Form form = .... //Got a an existing form from DB
model.addAttribute("form", form);
return "/form";
}
#RequestMapping(value="/{supplierId}", method=RequestMethod.POST)
public String post(HttpServletRequest request, #PathVariable Long supplierId, #Valid #ModelAttribute("form") Form form, BindingResult result, Model model, Principal principal){
System.out.println(form.getID()); //Here the id is 0
safeFoodFormService.store(form, supplierId);
return "redirect:/supplier";
}
My Freemarker form
<form class="form-horizontal" action="<#spring.url "/forms/${supplier.ID?c}"/>" method="post" command="form">
It will work if I do add this lines inside my form
<#spring.bind "form.ID" />
<input type="hidden" name="${spring.status.expression}" value="${spring.status.value default("")}" />
I would be very nice if this could be handled by Spring. Thanks
Spring data binding takes the request name/value pair and binds the corresponding properties with same name to corresponding value. So if there is no id request parameter present in request, spring mvc has no way to map its value in the model bean which would be injected in to the controller method. So by any mechanism the form must have a input (hidden or otherwise) to let the spring bind its value to the bean property.
My application uses submit name as action name consistently. It has worked so far.
Enter multipart form...
html
<form:form modelAttribute="screenObject" enctype="multipart/form-data">
<input name="save" value="Save" type="submit" />
Controller
public static final String ACTION_SAVE="save";
#RequestMapping(method=RequestMethod.POST, params=ACTION_SAVE)
public ModelAndView save(#ModelAttribute("screenObject") FileHeaderEditScreenObject screenObject, BindingResult bindingResult, Model model, Locale locale) {
Error
message Request method 'POST' not supported
If I remove enctype="multipart/form-data", control flows right into the save method. I do need different actions on this multipart form. I want to stay consitent so I hope I do not have to introduce any hidden fields to represent actions or submit the form to different urls...
I suggest to remove params=ACTION_SAVE from the annotation.
It look like that it doesn't parse submit action from a multipart request.
You can handle that parameter as a request parameter:
#RequestMapping(method=RequestMethod.POST, params=ACTION_SAVE)
public ModelAndView save(
#RequestParam(value = "submit", required = true) String action,
#ModelAttribute("screenObject") ....
{
switch (action) {
case "action1": ...
case "action2": ...
}
}
This is not very nice. I would just use different URLs like this:
#RequestMapping("/action1"})
public void action1(
#RequestMapping("/action2"})
public void action2(