I'm trying to setup a simple Liferay + Maven portlet that can utilize REST services to fetch data from an external database. I believe I'm most of the way there but I'm stuck on the #RequestMapping within a Liferay portlet. I have a #Controller setup that runs fine on the View phase of the portlet
#Controller
#RequestMapping(value = "VIEW")
public class RiskController {
#ActionMapping
public void handleActionRequest(ActionRequest request, ActionResponse response)throws Exception {
return;
}
#RenderMapping
public ModelAndView handleRenderRequest(RenderRequest request, RenderResponse response, ModelMap model) {
model.addAttribute("helloWord", "123");
return new ModelAndView("index", model);
}
}
Now I'd like to write some service classes and fetch my data, but I'm not sure how to set this up as far as the Paths/URLs are concerned from a Liferay perspective (i.e., localhost:8080/myPortlet/myAjaxCall). I want to do something basic like return an Object via JSON like so
#RequestMapping(value = "/getMyData/123", method = RequestMethod.GET)
public #ResponseBody Data getData(#RequestParam long gcfId) {
Data data = dataRepo.getMyData(123);
return data;
}
Can anyone help get me in the right direction? Can provide more code if needed
Related
Need some small help about Spring Feign client. So here is the situation,
I have 2 Spring boot services. Let’s say Service A and Service B. I have configured my Service A with Feign client through which I call the Service B method.
So here is the code for my Service A,
My FeignCleint config interface,
#FeignClient(name = "FeignClient", url = "http://localhost:8081/ServiceB/hello")
public interface FeignApi {
#RequestMapping(method = RequestMethod.GET)
ResponseEntity<?> hello();
}
And my rest controller that uses above feign config to call the Service B method,
#RestController
public class ApiController {
#Autowired
private FeignApi feignApi;
#RequestMapping(value = "/callServiceB")
public ResponseEntity<?> companyInfo() {
ResponseEntity<?> response = new ResponseEntity("OK Response", HttpStatus.OK);
try {
response = feignApi.hello();
// Code for some other things related to application.
return response;
} catch (Exception ex) {
System.out.println("Service A Exception block reached.");
return new ResponseEntity(ex.getMessage(), HttpStatus.BAD_REQUEST);
}
}
}
below is my controller for Service B,
#RestController
public class MyController {
#GetMapping("/hello")
public String hello() throws Exception {
if (true) {
throw new Exception("Service B Exception...");
}
return "Hello World";
}
}
And my Controller advice to handle the exception that I am manually throwing,
#ControllerAdvice
public class MyControllerAdvice {
#ExceptionHandler
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
public ResponseEntity<?> handleException(Exception exception, Model model) {
return new ResponseEntity<>("Caused due to : " + exception.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
}
}
Now my flow is like below,
As you can see, I am calling service B from service A using feign client. My service B is throwing an exception manually which I am catching using the controller advice and sending the exception details as an ResponseEntity back to the calling service A. So that Service A can process the details and move forward based on that.
The problem is when I hit the call from Service A using
http://localhost:8080/feign/callServiceB
The service B fails as expected. Now what I expect is that the Service A should receive the response back in form of the ResponseEntity. But what really happens is that the flow enters the exception block instead of staying in the try block. I can see this line printed,
"Service A Exception block reached."
This is what I don't understand. If I have managed the service B exception using controller advice and sent back the response to service A in form of ResponseEntity, then how come the flow of service A enters catch block. I expect it to stay in try block only as I want to process further based on the data.
Any idea, how can I get around this thing? Or is this how it will behave even when I am using controller advice to manage exceptions? What should be the expected behavior in this case?
Please advice.
By default Feign throws FeignException for any error situation.
Make use of fallback mechanism to handle failures.
#FeignClient(name = "FeignClient", url = "http://localhost:8081/ServiceB/hello", fallback= FeignApiFallback.class)
public interface FeignApi {
#RequestMapping(method = RequestMethod.GET)
ResponseEntity<?> hello();
}
#Component
class FeignApiFallback implements FeignApi {
#Override
public ResponseEntity<?> hello() {
//do more logic here
return ResponseEntity.ok().build();
}
}
make sure you add below property to wrap methods in hystrix commands in recent releases
feign.hystrix.enabled=true
Any status other than 200, feign client will consider it as an exception and you are setting HttpStatus.INTERNAL_SERVER_ERROR in your controller advice.
You can use custom ErrorDecoder
refer https://github.com/OpenFeign/feign/wiki/Custom-error-handling
I am creating a very basic application with SpringBoot and Thymeleaf. In the controller I have 2 methods as follows:
Method1 - This method displays all the data from the database:
#RequestMapping("/showData")
public String showData(Model model)
{
model.addAttribute("Data", dataRepo.findAll());
return "show_data";
}
Method2 - This method adds data to the database:
#RequestMapping(value = "/addData", method = RequestMethod.POST)
public String addData(#Valid Data data, BindingResult bindingResult, Model model) {
if (bindingResult.hasErrors()) {
return "add_data";
}
model.addAttribute("data", data);
investmentTypeRepo.save(data);
return "add_data.html";
}
HTML files are present corresponding to these methods i.e. show_data.html and add_data.html.
Once the addData method completes, I want to display all the data from the database. However, the above redirects the code to the static add_data.html page and the newly added data is not displayed. I need to somehow invoke the showData method on the controller so I need to redirect the user to the /showData URL. Is this possible? If so, how can this be done?
Try this:
#RequestMapping(value = "/addData", method = RequestMethod.POST)
public String addData(#Valid Data data, BindingResult bindingResult, Model model) {
//your code
return "redirect:/showData";
}
sparrow's solution did not work for me. It just rendered the text "redirect:/"
I was able to get it working by adding HttpServletResponse httpResponse to the controller method header.
Then in the code, adding httpResponse.sendRedirect("/"); into the method.
Example:
#RequestMapping("/test")
public String test(#RequestParam("testValue") String testValue, HttpServletResponse httpResponse) throws Exception {
if(testValue == null) {
httpResponse.sendRedirect("/");
return null;
}
return "<h1>success: " + testValue + "</h1>";
}
Below Solution worked for me.
getAllCategory() method displays the data and createCategory() method add data to the database. Using return "redirect:categories";, will redirect to the getAllCategory() method.
#GetMapping("/categories")
public String getAllCategory(Model model) {
model.addAttribute("categories",categoryRepo.findAll());
return "index";
}
#PostMapping("/categories")
public String createCategory(#Valid Category category) {
categoryRepo.save(category);
return "redirect:categories";
}
OR using ajax jQuery also it is possible.
You should return a http status code 3xx from your addData request and put the redirct url in the response.
I use spring-boot as a backend server. It has tens of Action Methods. As usual Some of them contains validation. Actually I use BindingResult and returns validation error for returning Http 400 Status.
#CrossOrigin
#RestController
public class ValidationTestController {
#RequestMapping(value = {"/validation-test", "/validation-test/"}, method = RequestMethod.POST)
#ResponseBody
public ResponseEntity<String> login(#RequestBody #Valid final TestData data, final BindingResult result) {
if (result.hasErrors()) {
return new ResponseEntity<>("Sorry incoming data is not valid!", HttpStatus.BAD_REQUEST);
}
return new ResponseEntity<>("OK!", HttpStatus.OK);
}
private static final class TestData {
#NotNull
private String value;
}
}
My aim is removing follpwing lines:
if (result.hasErrors()) {
return new ResponseEntity<>("Sorry incoming data is not valid!", HttpStatus.BAD_REQUEST);
}
IMHO it's a cross cutting concern like Authentication and Auditing. I want to handle it in a one global ErrorHandler Method. It's possible to throw a CustomValidationException Before executing the method. So I can handle the exception in ErrorController.
Yes, you can centralize the exception handling logic at one place, using #ExceptionHandler which is a ControllerAdvice from Spring.
You can look at here
I'm using Spring 3.1.0.RELEASE. For some reason, in my controller, when I POST my form and return the original screen when an error occurs, model attributes are not getting populated like they do when I invoke the page through a GET method. In my controller I have
#Controller
public class StandardsUploadController {
…
#RequestMapping(value = "/upload")
public String getUploadForm(Model model) {
model.addAttribute(new StandardsUploadItem());
model.addAttribute("gradeList", gradeList);
model.addAttribute("subjectList", subjectList);
return "upload/index";
}
#RequestMapping(value = "/upload", method = RequestMethod.POST)
public ModelAndView processFile(final StandardsUploadItem uploadItem,
final BindingResult result,
final HttpServletRequest request,
final HttpServletResponse response) throws InvalidFormatException, CreateException, NamingException {
stdsUploadValidator.validate(uploadItem, result);
if (!result.hasErrors()) {
try {
…
} catch (IOException e) {
LOG.error(e.getMessage(), e);
e.printStackTrace();
}
} // if
return new ModelAndView("upload/index");
}
What am I doing wrong and how can I correct it?
When you return to the upload/index view from the POST, it is not re-populating the Model, since your code to populate the model is done on the GET.
One potential option is to use the #ModelAttribute annotation in your Controller class
You would have, for example, a method that looks like this for the StandardsUploadItem:
#ModelAttribute("uploadItem")
public StandardsUploadItem getStandardsUploadItem(){
return new StandardsUploadItem();
}
You could then remove the line below from your GET method:
model.addAttribute(new StandardsUploadItem());
Since a method annotated with #ModelAttribute and returning an object will automatically be put in the ModelMap, regardless of which Controller RequestMapping method is activated.
Your method signature for the POST method would contain something like this:
..., #ModelAttribute("uploadItem") StandardsUploadItem uploadItem, ...
You would need to do something similar for the other attributes in your model (gradeList, and subjectList), but since you do not seem to need them on the POST, you could do something like add a Model parameter to your POST method signature, and re-populate that Model before you return the ModelAndView in the error case.
I am setting up a simple RESTful controller for a Todo resource with an XML representation. It all works great - until I try to redirect. For example, when I POST a new Todo and attempt to redirect to its new URL (for example /todos/5, I get the following error:
Error 500 Unable to locate object to be marshalled in model: {}
I do know the POST worked because I can manually go to the new URL (/todos/5) and see the newly created resource. Its only when trying to redirect that I get the failure. I know in my example I could just return the newly created Todo object, but I have other cases where a redirect makes sense. The error looks like a marshaling problem, but like I said, it only rears itself when I add redirects to my RESTful methods, and does not occur if manually hitting the URL I am redirecting to.
A snippet of the code:
#Controller
#RequestMapping("/todos")
public class TodoController {
#RequestMapping(value="/{id}", method=GET)
public Todo getTodo(#PathVariable long id) {
return todoRepository.findById(id);
}
#RequestMapping(method=POST)
public String newTodo(#RequestBody Todo todo) {
todoRepository.save(todo); // generates and sets the ID on the todo object
return "redirect:/todos/" + todo.getId();
}
... more methods ...
public void setTodoRepository(TodoRepository todoRepository) {
this.todoRepository = todoRepository;
}
private TodoRepository todoRepository;
}
Can you spot what I am missing? I am suspecting it may have something to do with returning a redirect string - perhaps instead of it triggering a redirect it is actually being passed to the XML marshaling view used by my view resolver (not shown - but typical of all the online examples), and JAXB (the configured OXM tool) doesn't know what to do with it. Just a guess...
Thanks in advance.
This happend because redirect: prefix is handled by InternalResourceViewResolver (actually, by UrlBasedViewResolver). So, if you don't have InternalResourceViewResolver or your request doesn't get into it during view resolution process, redirect is not handled.
To solve it, you can either return a RedirectView from your controller method, or add a custom view resolver for handling redirects:
public class RedirectViewResolver implements ViewResolver, Ordered {
private int order = Integer.MIN_VALUE;
public View resolveViewName(String viewName, Locale arg1) throws Exception {
if (viewName.startsWith(UrlBasedViewResolver.REDIRECT_URL_PREFIX)) {
String redirectUrl = viewName.substring(UrlBasedViewResolver.REDIRECT_URL_PREFIX.length());
return new RedirectView(redirectUrl, true);
}
return null;
}
public int getOrder() {
return order;
}
public void setOrder(int order) {
this.order = order;
}
}