One of my methods need to return just a simple string of text. What should be the return type of the method? Do I still declare it in a subclass of ApiController?
I tried the following but it does not work:
public class TestController : ApiController
{
public string Announcements()
{
return "Testing abc";
}
}
By default, Web API will send the string as a JSON. However, you can manually force it to return just the text itself and accompany it with the appropriate content type:
public class TestController : ApiController
{
public HttpResponseMessage Announcements()
{
var response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content = new StringContent("Testing abc");
response.Content.Headers.ContentType = new MediaTypeHeaderValue("text/plain");
return response;
}
}
Related
Any Help please !!
I receive this error when I'm calling my endpoint which call Feign in the background :
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of
`org.springframework.http.ResponseEntity` (no Creators, like default constructor, exist): cannot deserialize
from Object value (no delegate- or property-based Creator)
at [Source: (BufferedReader); line: 1, column: 2]
This is my endpoint inside Controller :
#RestController
#RequestMapping(Routes.URI_PREFIX)
public class CartoController {
#Autowired
private ReadCartographyApiDelegate readCartographyApiDelegate;
#GetMapping(value = "/cartographies/{uid}", produces = {MediaType.APPLICATION_JSON_VALUE})
public ResponseWrapper<ReadCartographyResponse> readCarto(HttpServletRequest request,
#PathVariable(name = "uid") String uid) {
ResponseEntity<ReadCartographyResponse> result ;
try {
result = readCartographyApiDelegate.readCartography(uid);
}catch (Exception e){
throw new TechnicalException("Error during read Carto");
}
return responseWrapperWithIdBuilder.of(result.getBody());
}
}
Interface ReadCartographyApiDelegate generated automatically by openApi from yaml file :
#javax.annotation.Generated(value = "org.openapitools.codegen.languages.SpringCodegen", date = "...")
public interface ReadCartographyApiDelegate {
default Optional<NativeWebRequest> getRequest() {
return Optional.empty();
}
default ResponseEntity<ReadCartographyResponse> readCartography(String uid) {
getRequest().ifPresent(request -> {
for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
String exampleString = "null";
ApiUtil.setExampleResponse(request, "application/json", exampleString);
break;
}
}
});
return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
}
}
This my ReadCartoApiDelegateImpl which implements ReadCartographyApiDelegate interface :
#Service
public class ReadCartographyApiDelegateImpl implements ReadCartographyApiDelegate {
private EcomGtmClient ecomGtmClient;
public ReadCartographyApiDelegateImpl(EcomGtmClient ecomGtmClient) {
this.ecomGtmClient = ecomGtmClient;
}
#Override
public ResponseEntity<ReadCartographyResponse> readCartography(String uid) {
ResponseEntity<ReadCartographyResponse> response = ecomGtmClient.readCartography(uid);
return response;
}
}
This is the feign client :
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ResponseEntity<ReadCartographyResponse> readCartography(#PathVariable("uid") String uid);
}
The problem is that ResponseEntity (spring class) class doesn't contain default constructor which is needed during creating of instance. is there Any config to resolve this issue ?
If you want access to the body or headers on feign responses, you should use the feign.Response class. ResponseEntity does not work with feign because it is not meant to. I think it is best if you just return Response from your feign client method. You should then be able to pass the body to the ResponseEntity instance in the Controller.
What is your reason to even use the response-wrapper, i can't really figure that out from your code?
Sadly I couldn't find any documentation on the Response class, but here's the link to the source on GitHub.
https://github.com/OpenFeign/feign/blob/master/core/src/main/java/feign/Response.java
My Suggestion would be
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ReadCartographyResponse readCartography(#PathVariable("uid") String uid);
}
#RestController
#RequestMapping(Routes.URI_PREFIX)
public class CartoController {
#Autowired
private ReadCartographyApiDelegate readCartographyApiDelegate;
#GetMapping(value = "/cartographies/{uid}", produces = {MediaType.APPLICATION_JSON_VALUE})
public ResponseWrapper<ReadCartographyResponse> readCarto(HttpServletRequest request,
#PathVariable(name = "uid") String uid) {
ReadCartographyResponse result ;
try {
result = readCartographyApiDelegate.readCartography(uid);
}catch (Exception e){
throw new TechnicalException("Error during read Carto");
}
// I don't know where you get the builder from, so I assume it does something import and is needed
return responseWrapperWithIdBuilder.of(result);
}
}
Of course you'd also have to change all intermediate classes.
The Response Output was the correct Object that I have to put, cause every time I need to check the status from my feign client endpoint to do différent logic
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ReadCartographyResponse readCartography(#PathVariable("uid") String uid);
}
I would like to return two different response for a spring boot rest API.
I should not be using <?> wild card as i get the sonar issue "Generic wildcard types should not be used in return types"
My code:
#GetMapping(path = {"/v1/{type}"}, produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<?> method(#PathVariable(value = "type") boolean type) {
boolean b = type;// some logic
if (b) {
Success result=new Success();
result.setSuccess("Yes");
return new ResponseEntity<>(result,HttpStatus.OK);
}
else {
Error result=new Error();
result.setError("No");
return new ResponseEntity<>(result,HttpStatus.CONFLICT); //appropriate error code
}
}
Any idea how to handle this situation.
Update:
public interface MyResponse{
public Success getSuccessObj();
public Error getErrorObj();
}
#Service
public class Success implements MyResponse {
public Error getErrorObj(){
return null;
}
public Success getSuccessObj(){
Success s=new Success();
return s;
}
#Service
public class Error implements MyResponse {
public Error getErrorObj(){
Error e=new Error();
return e;
}
public Success getSuccessObj(){
return null;
}
Not claiming to be "the best way", but one approach can be:
Introduce:
package com.my.package;
public interface MyResponseI { //if Error, Success (and others) have more "in common", you can also introduce an (abstract) class (with fields, methods, etc.)!
}
"Implement"/Extend:
public class Success implements com.my.package.MyResponseI { //everything else can stay}
as
public class Error implements com.my.package.MyResponseI { //everything else can stay}
Use as Response Type:
#...
public ResponseEntity<com.my.package.MyResponseI> ...
(on client side distinguish).
..and in "your domain" (error, success, ...), you are free to use any "tweaks" of a object oriented design.
Useful links/entries:
https://stackoverflow.blog/2020/03/02/best-practices-for-rest-api-design/
https://swagger.io/resources/articles/best-practices-in-api-design/
https://www.google.com/search?q=rest+api+design
, but also
https://www.google.com/search?q=object+oriented+design
and https://www.google.com/search?q=domain+driven+design
This should work
I tried the snippet below by myself and it worked for me:
#GetMapping("/testresponse/{id}")
public ResponseEntity<?> testMyResponse(#PathVariable("id") int id)
{
if(id==1)
return ResponseEntity.ok(new Success());
else return new ResponseEntity<>(new Error(), HttpStatus.CONFLICT);
}
public class Success {
private String msg = "Success";
public String getMsg() {
return msg;
}
}
public class Error {
private String msg = "Error";
public String getMsg() {
return msg;
}
}
EDIT: The solution as below doesn't work
You should also define an interface for both Success and Error classes. Let say the interface MyResponse
And then change your method declaration, it would look like this
public ResponseEntity<MyResponse> method(#PathVariable(value = "type") boolean type)
If so, the return statement, could be:
return new ResponseEntity<>(result, HttpStatus.OK);
Or
//for status 200 OK
return ResponseEntity.ok(result);
So Basically i wrote a validator for my class with FluentValidation and also a filter to do the validation task for me in my webAPI project, so far it's OK but assume that my User class has firstname,lastname,email,password properties
and i have two routes (one for register and the other one for login)
and as you might have noticed required properties are different on these route.
Thus,should I really need to write individual validation for each and every action i have?because this makes a lot of code code duplication and it's hard to change.is there any way to just add required condition based on the request coming with single validation class?
Any suggestion???
A better practice would be to use a factory pattern for your validations and use a an action filter to short circuit bad requests. You could validate any action argument(Headers, Request Bodies, etc..) with something like this.
public class TestValidationAttribute : Attribute, IActionFilter
{
private string _requestModelName;
public TestValidationAttribute(string requestModelName)
{
_requestModelName = requestModelName;
}
public void OnActionExecuting(ActionExecutingContext context)
{
// using Microsoft.Extensions.DependencyInjection;
var services = context.HttpContext.RequestServices;
var accessor = services.GetService<IHttpContextAccessor>();
var factory = services.GetService<ITestValidatorFactory>();
var tokens = accessor.HttpContext.GetRouteData().DataTokens;
if (!tokens.TryGetValue("RouteName", out var routeNameObj))
{
throw new Exception($"Action doesn't have a named route.");
}
var routeName = routeNameObj.ToString();
var validator = factory.Create(routeName);
if (!context.ActionArguments.TryGetValue(_requestModelName, out var model))
{
throw new Exception($"Action doesn't have argument named {_requestModelName}.");
}
TestModel test;
try
{
test = (TestModel) model;
}
catch (InvalidCastException)
{
throw new Exception($"Action argument can't be casted to {nameof(TestModel)}.");
}
var validation = validator.Validate(test);
if (!validation.Successful)
{
context.Result = new BadRequestObjectResult(validation.ResponseModel);
}
}
public void OnActionExecuted(ActionExecutedContext context)
{
}
}
public class TestController : Controller
{
[HttpPost]
[Route("Test/{id}", Name = "TestGet")]
[TestValidation("model")]
public IActionResult Test(TestModel model)
{
return Ok();
}
}
public class ValidationResult
{
public bool Successful { get; }
public ResponseModel ResponseModel { get; }
}
public class TestModel
{
}
public interface ITestValidator
{
ValidationResult Validate(TestModel model);
}
public interface ITestValidatorFactory
{
ITestValidator Create(string routeName);
}
Hi I have this controller method that returns a list of customers and displays it using a model.
#Controller
public class timesheetController
{
#Autowired
private CustomerDAO customerDAO;
#GetMapping("/getCustomers")
public String getCustomers(Model view)
{
//get customers from dao
List<Customer> results = customerDAO.getCustomers();
//add the customers to the model
view.addAttribute("customers", results);
return "list-customers";
}
}
However I would like to return the list as a json to get an output like
{
"Customer_Code": T77A,
"Customer_Name": CustomerName1
},
{
"Customer_Code": T77B,
"Customer_Name": CustomerName2
}
I tried just returning the list as follows
#Controller
public class timesheetController
{
#Autowired
private CustomerDAO customerDAO;
#GetMapping("/getCustomers")
public List<Customer> getCustomers()
{
//get customers from dao
List<Customer> results = customerDAO.getCustomers();
return results;
}
}
but then I get this error as it seems to be expecting a view. How can I return the desired json output?
well you are trying to call getCustomers.jsp. What you want, instead, is not a JSP page but a JSON response. So you should make an AJAX call (by using JQuery or other framework or native JS)
So what I would do is change your Controller class in this way:
#Controller
public class timesheetController
{
#Autowired
private CustomerDAO customerDAO;
#GetMapping("/getCustomers", consumes = MediaType.APPLICATION_JSON_UTF8_VALUE, produces = {MediaType.APPLICATION_JSON_UTF8_VALUE })
public ResponseEntity<List<Customer>> getCustomers()
{
List<Customer> payload = customerDAO.getCustomers();
return ResponseEntity
.ok()
.contentType(MediaType.APPLICATION_JSON_UTF8)
.body(payload);
}
}
Then I would make the JSON call (I'm using JQuery in this example):
var baseUrl = YOUR_WEB_APP_CONTEXT/getCustomers;
$.ajax({
type: "GET",
url: baseUrl,
success: function(data) {
//All OK.. you should have the JSON response
},
error: function() {
//Something was wrong; you chould check
}
});
I've created WebApi controller based on following tutorial: sebastienros website
My modules name is Company.Accounts.
public class AccountController : ApiController
{
[HttpPost]
public string LogIn([FromBody] UserModel user)
{
// this is working
return this.accountService.LogIn(user.UserName, user.Password);
}
[HttpPut]
public string SomePuthMethod([FromBody] UserModel user)
{
// method not allowed
// some code...
}
}
Implementation of IHttpRouteProvider looks like:
private IEnumerable<RouteDescriptor> GetAccountRoute()
{
yield return new HttpRouteDescriptor
{
Name = "Account",
Priority = 10,
RouteTemplate = "Api/Account",
Defaults = new
{
area = "Company.Accounts",
controller = "Account"
}
};
}
Unfortunately, everything except GET and POST *is not working*. I'm getting simple
Method not allowed.
What's wrong? My Orchard version is 1.7.1.
You put them in the MethodNames public HttpResponseMessage Post([FromBody]...){}