I am new to both Spring and the REST API overall but I am now trying to make one. So from my controller, I want to return a list of files that another method returns in another class. The code probably says more then I can explain:
#RequestMapping("/backup")
public #ResponseBody List<FileInfo> backupFiles() {
return //Here i want to return the list of files
}
This is in my restController the "method" i want to return a list of FileInfo and today it already exists a method that does this that looks like this
private List<String> listBackupFiles() {
List<FileInfo> files = util.listBackupFilesInLocalDir(localStorage);
fileNameToSize = files.stream()
.collect(toMap(f -> f.name, f -> f.size));
return files.stream()
.map(f -> f.name)
.collect(toList());
}
So basically, I want to when someone goes to /backup I want the above method to trigger and return the list of files to my restController that then returns it to the requester. I don't know if this is even possible or if there is a better way to do this. I take any tips on how to tackle this problem.
The controller would be:
// #RestController = #Controller + #ResponseBody
#RestController
public class BackupController {
#Autowired
private BackupService backupService;
// you don't need #ResponseBody as you use #RestController
#RequestMapping("/backup")
public List<FileInfo> backupFiles() {
return backupService.listBackupFiles()
}
}
The service interface would be:
public interface BackupService {
public List<FileInfo> listBackupFiles();
}
The service implementation would be:
#Service
public class BackupServiceImpl implements BackupService {
public List<FileInfo> listBackupFiles() {
// localStorage come from
// maybe Util has it as static method, else inject it
return util.listBackupFilesInLocalDir(localStorage);
}
}
Hope was helpful :)
Related
I am a newbie in Spring development. I need to create a simple application, a controller that has a method that takes as parameter an object of a custom designed entity class into the project. The prototype looks like this:
#RestController
public class JobsController {
#PostMapping("/search")
public ResponseEntity<?> search() {
log.info("JobsController -> search method");
//JobSearchEntity jobSearchEntity = modelMapper.map(jobSearch, JobSearchEntity.class);
List<JobEntity> jobs = jobService.searchJobs();
//log.info(String.format("Job found: %s ", jobSearch));
return ResponseEntity.ok(jobs);
}
}
Can someone who is more advanced into this staff with Postman testing tell me how to do that , how to test a controller method which takes parameters?
You can use postman to submit parameters in JSON format after adding # requestbody annotation on the method, or submit parameters directly in form without annotation
You can use this example. Is very simple exemple.
#RestController
#RequestMapping("/root")
public class RootController {
private final RootService service;
public RootController(final RootService service) {
this.service = service;
}
#PostMapping("/exemple")
public void createRoot(#RequestBody final RootDto dto) {
service.createRoot(dto);
}
}
Then you can send request to POST host/root/exemple with your JSON.
More exampls you can find here: https://www.baeldung.com/spring-request-response-body
It seems you are missing an honest search on google about the subject.
You can make use of #RequestBody annotation to accept method arguments.
Check these page for examples --
#RequestBody and #ResponseBody annotations in Spring
https://stackabuse.com/get-http-post-body-in-spring/
https://www.twilio.com/blog/create-rest-apis-java-spring-boot
These set of playlist on youtube are very good starter course for SpringBoot -
https://www.youtube.com/c/JavaBrainsChannel/playlists
Postman Tutorial--
https://www.youtube.com/watch?v=VywxIQ2ZXw4
To get data from api is preferred to use GET method :
#RestController
public class JobsController {
#GetMapping("/search")
public ResponseEntity<?> search(#RequestParam("id") String id,#RequestParam("desc") String desc) {
log.info("JobsController -> search method");
//JobSearchEntity jobSearchEntity = modelMapper.map(jobSearch, JobSearchEntity.class);
List<JobEntity> jobs = jobService.searchJobs();
//log.info(String.format("Job found: %s ", jobSearch));
return ResponseEntity.ok(jobs);
}
}
you call this api with post man this way :
#PostMapping used usually to save new data (example : create job )
Take look on rest resource naming guide
Right now I use
#PreAuthorize("hasAuthority('CREATE_USER_PRIVILEGE')")
But I want the CREATE_USER_PRIVILEGE to come from a function(). Is this possible?
You could do something like this:
#RestController
class FooController {
#PreAuthorize("hasAuthority(#securityService.privilege)")
#GetMapping("/")
public ResponseEntity<String> helloSecurity(#RequestParam("id") Integer id){
return ResponseEntity.ok("Hello World");
}
}
#Service("securityService")
class SecurityService {
public String getPrivilege(){
return "CREATE_USER_PRIVILEGE";
}
}
Based on this great article
you have first to autowire your service using constructor or annotation then you can use the Spel language to use it as stated in the following example
#RequestMapping(value="/id/{domainObjectId}/dostuff", method=RequestMethod.POST, produces="application/json")
#PreAuthorize(value="hasRole('ROLE_DomainObjectAdmin') or #domainObjectServiceImpl.findDomainObject(#domainObjectId).getOwners().contains(#userAccount.getEmployee())")
public String setObjectiveComplete(#PathVariable String domainObjectId, UserAccount userAccount) {
// Do stuff
}
Based on the above solution, I've implemented something like this:
#Controller
class TestController {
//calling a PreAuthorize on method level/ can be used on class level as well
#PreAuthorize("hasAnyAuthority(#authorityService.authorities)")
#RequestMapping("/application")
public ModelAndView newPage() throws{
return new ModelAndView(view);
}
}
#Service("authorityService")
class AuthorityService{
#Value("${app.authorities}") // read roles from properties file
private String authorities;
public List<String> getAuthorities(){
// convert the comma separated Strings to list.
List<String> items = Arrays.asList(authorities.split("\\s*,\\s*"));
return items;
}
}
I am learning spring boot, and i developed the below simple example. I would like to annotate a class as Controller using #Controller. this class has constructor and I want to have access to GreetingFromDeuController as shown:
http://localhost:8080:/GreetingFromDeuController?str = "hi"
the error i am receiving is
#RequestMapping is not applicable on a constructor
please let me know how to solve.
code:
#Controller
#RequestMapping("/GreetingFromDeuController")
public class GreetingFromDeuController {
private String str;
#RequestMapping("/GreetingFrom/deu")
GreetingFromDeuController(#RequestParam(value = "str") String str) {
this.str = str;
}
#RequestMapping("/GreetingFromDeuController")
public String getGreetingFromDeu() {
return this.str;
}
}
First of all your constructor gets initialize much before you hit your URL. So you need to work on your design or tell me your business requirement and I will try to provide you a solution. My refactor code solution will help you to achieve that in two steps. First hit POST method which will do work on setting variable and then subsequent hits of GET method will return that set value.
We can refactor code like below. It will explain use of RequestMapping on method and class.
Considering we have to write two API, one for reading and one for writing.
URLS :
1. POST http://localhost:8080/example/greetings (in request body send {str:'hi'})
2. GET http://localhost:8080/example/greetings
#Controller
#RequestMapping("/example")
public class GreetingFromDeuController {
private String str;
#RequestMapping(value="/greetings" , method = RequestMethod.POST)
public void setGreetingFromDeu(#RequestBody(value = "str") String str)
{
this.str = str;
}
#RequestMapping(value="/greetings" , method = RequestMethod.GET)
public String getGreetingFromDeu()
{
return this.str;
}
}
The #RequestMapping documentation says:
Annotation for mapping web requests onto methods in request-handling
classes with flexible method signatures.
Then you can not do that, if you want to initialize your variables or whatever you can use several ways:
1.- Use #PostConstruct
#PostContruct
public void init() {
this.str = "Anything";
}
2.- Use a simple request to set anything only
#RequestMapping(value="/refresh/anythings", method = RequestMethod.PUT)
public void refresh(#RequestBody(value = "str") String str) {
this.str = str;
}
3.- Use #Value
In application.properties / application.yaml
properties.str = anything
In the Controller
#Value("${properties.str:default}") // by default str is "default"
public String str;
#RequestMapping(value="/greetings" , method = RequestMethod.GET)
public String getGreetingFromDeu() {
return this.str;
}
As far I am concerned, #RequestMapping is not meant for constructors. It should be used for annotating methods or classes. Methods that are responsible for handling requests.
#RequestMapping should be used to map request with endPoint. which can be used as class level and method level.
You can use #RestController (improved from #Controller see difference).
The ideal flow for Spring Boot is Controller -> Service -> Repository
Controller -> maps request with endPoint and return response
Service -> perform business logic
Repository -> Handle database operation
Example
#RestController
#RequestMapping("/api")
public class GreetingController {
#Autowired GreetinService greetingService;
// Request http://localhost:8080/api/GreetingFrom
#GetMapping("/GreetingFrom")
public ResponseEntity<String> GreetingRequestParam(#RequestParam(value = "name") String name) {
greetingService.performBusinessLogic(name);
return new ResponseEntity<String>("Greetings from "+name,HttpStatus.OK);
}
// Request http://localhost:8080/api/GreetingFrom/user2121
#GetMapping("/GreetingFrom/{name}")
public ResponseEntity<String> GreetingPathVariable(#PathVariable(value = "name") String name) {
return new ResponseEntity<String>("Greetings from "+name,HttpStatus.OK);
}
}
I have a little problem. I'm calling AfterReturning function after some function returns and my AfterReturning function's working twice and I don't want that. Here is the code:
#Aspect
#Component
#Configuration
public class AspectOP {
LogController logcontroller = new LogController();
#AfterReturning("execution(* com..*save*(..))")
public void doSomething() {
logcontroller.guestbook("XD");
}
}
I have 2 save function and we changed names but it's same again. I've tried remove #Component or #Aspect then it's not working.
EDIT
My save function
#Controller
#RequestMapping("/api")
public class EntryController {
#Autowired
EntryRepository repo;
Account account;
#RequestMapping(path = "/getir", method = RequestMethod.GET)
public #ResponseBody List<Entries> getir(){
return repo.findAll();
}
#RequestMapping(path = "/saveentry", method = RequestMethod.POST, consumes = "application/json")
public #ResponseBody Entries save(#RequestBody Entries entry) {
return repo.save(entry);
}
}
LogController.class
#Controller
public class LogController {
#MessageMapping("/guestbook")
#SendTo("/topic/entries")
public Log guestbook(String message) {
System.out.println("Received message: " + message);
return new Log(message);
}
}
My main objective is when something is saved, I send something to my socket. It's working but doSomething functions is working twice.
seems advice applied to your EntryRepository class as well. change your pointcut expression to something like, to be only applied to EntryController's save method
#AfterReturning("execution(* com.xyz.EntryController.save*(..))")
Examples here
I'm attempting to add some additional business logic to the auto-generated endpoints from the RepositoryRestResource. Please see the code below:
Resource:
#RepositoryRestResource(collectionResourceRel="event", path="event")
public interface EventRepository extends PagingAndSortingRepository<Event, Long> {
}
Controller:
#RepositoryRestController
#RequestMapping(value = "/event")
public class EventController {
#Autowired
private EventRepository eventRepository;
#Autowired
private PagedResourcesAssembler<Event> pagedResourcesAssembler;
#RequestMapping(method = RequestMethod.GET, value = "")
#ResponseBody
public PagedResources<PersistentEntityResource> getEvents(Pageable pageable,
PersistentEntityResourceAssembler persistentEntityResourceAssembler) {
Page<Event> events = eventRepository.findAll(pageable);
return pagedResourcesAssembler.toResource(events, persistentEntityResourceAssembler);
}
}
I've looked at the following two stackoverflow articles:
Can I make a custom controller mirror the formatting of Spring-Data-Rest / Spring-Hateoas generated classes?
Enable HAL serialization in Spring Boot for custom controller method
I feel like I am close, but the problem that I am facing is that:
return pagedResourcesAssembler.toResource(events, persistentEntityResourceAssembler);
returns an error saying:
"The method toResource(Page<Event>, Link) in the type PagedResourcesAssembler<Event> is not applicable
for the arguments (Page<Event>, PersistentEntityResourceAssembler)".
The toResource method has a method signature that accepts a ResourceAssembler, but I'm not sure how to properly implement this and I can't find any documentation on the matter.
Thanks in advance,
- Brian
Edit
My issue was that I thought I could override the controller methods that are auto-created from #RepositoryRestResource annotation without having to create my own resource and resource assembler. After creating the resource and resource assembler I was able to add my business logic to the endpoint.
Resource:
public class EventResource extends ResourceSupport {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
Resource Assembler:
#Component
public class EventResourceAssembler extends ResourceAssemblerSupport<Event, EventResource> {
public EventResourceAssembler() {
super(EventController.class, EventResource.class);
}
#Override
public EventResource toResource(Event entity) {
EventResource eventResource = createResourceWithId(entity.getId(), entity);
eventResource.setName(entity.getName());
return eventResource;
}
}
Updated Controller:
#RepositoryRestController
#RequestMapping(value = "/event")
public class EventController {
#Autowired
private EventRepository eventRepository;
#Autowired
private EventResourceAssembler eventResourceAssembler;
#Autowired
private PagedResourcesAssembler<Event> pageAssembler;
#RequestMapping(method = RequestMethod.GET, value = "")
#ResponseBody
public PagedResources<EventResource> getEvents(Pageable pageable) {
Page<Event> events = eventRepository.findAll(pageable);
// business logic
return pageAssembler.toResource(events, eventResourceAssembler);
}
}
The thing I don't like about this is that it seems to defeat the purpose of having a RepositoryRestResource. The other approach would be to use event handlers that would get called before and/or after the create, save, delete operations.
#RepositoryEventHandler(Event.class)
public class EventRepositoryEventHandler {
#HandleBeforeCreate
private void handleEventCreate(Event event) {
System.out.println("1");
}
}
There doesn't seem to be any events for the findAll or findOne operations. Anyways, both these approaches seem to solve my problem of extending the auto generated controller methods from RepositoryRestResource.
It requires a PagedResourcesAssembler, Spring will inject one for you if you ask.
public PagedResources<Foo> get(Pageable page, PagedResourcesAssembler<Foo> assembler) {
// ...
}
In this case the resource is Foo. It seems in your case the resource you're trying to return is an Event. If that's so, I would expect your code to look something like:
private ResourceAssembler<Event> eventAssembler = ...;
public PagedResources<Event> get(Pageable page, PagedResourcesAssembler<Event> pageAssembler) {
Event event = ...;
return eventAssembler.toResource(event, pageAssembler);
}
You provide the ResourceAssembler<Event> that tells Spring how to turn Event into a Resource. Spring injects the PagedResourcesAssembler<Event> into your controller method to handle the pagination links. Combine them by calling toResource and passing in the injected pageAssembler.
The final result can be returned simply as a body as above. You could also use things like HttpEntity to gain more control over status codes and headers.
Note: The ResourceAssembler you provide can literally be something as simple as wrapping the resource, such as Event, with a Resource object. Generally you'll want to add any relevant links though.
To hack it you can use just PagedResourcesAssembler<Object> like:
#RequestMapping(method = RequestMethod.GET, value = "")
#ResponseBody
public PagedModel<PersistentEntityResource> getEvents(
Pageable pageable,
PersistentEntityResourceAssembler persistentAssembler,
PagedResourcesAssembler<Object> pageableAssembler
) {
return pageableAssembler.toModel(
(Page<Object>) repository.findAll(pageable),
persistentAssembler
);
}