Hi i would like know how to have in my controller without any blocking code transformation from two arguments to Mono of DTO class.
Suppose I have controller like below:
#RestController
#RequiredArgsConstructor
class GithubRepositoryEndpoint {
private final GithubService githubService;
#GetMapping("/repositories/{owner}/{repositoryName}")
Mono<RepoDetailsResponseDTO> getRepositoryDetails(#PathVariable("owner") String owner,
#PathVariable("repositoryName") String repositoryName) {
return githubService.getRepositoryDetails(Mono.just(new RepoDetailsRequestDTO(owner, repositoryName)));
}
}
I think this line is blocking:
Mono.just(new RepoDetailsRequestDTO(owner, repositoryName)
and here is DTO class:
#Data
#Builder
#AllArgsConstructor
public class RepoDetailsRequestDTO {
private String owner;
private String repositoryName;
}
My service is not blocking:
#Slf4j
#RequiredArgsConstructor
public class GithubService {
private final GithubClient githubClient;
private final RequestValidator requestValidator;
private final DomainMapper domainMapper;
public Mono<RepoDetailsResponseDTO> getRepositoryDetails(Mono<RepoDetailsRequestDTO> request) {
return request.map(requestValidator::validate)
.map(domainMapper::mapFromDto)
.flatMap(ownerAndRepoName -> githubClient.fetchRepositoryDetails(ownerAndRepoName._1, ownerAndRepoName._2))
.onErrorResume(exc -> Mono.error(new FetchRepoDetailsException(exc.getMessage(), exc)));
}
}
the line
Mono.just(new RepoDetailsRequestDTO(owner, repositoryName))
is not blocking. It is just a constructor invocation. It does not use any blocking APIs (e.g. io/file/network). Both parameters owner and repositoryName can be safely accessed as they already contain the parsed path variables.
Related
I use snake_case DB columns and camelCase DTO.
And our team want to use snake_case when we code React component.
Because of it, I added #JsonNaming on DTO. But it works when I send Json data, as you know.
Is there any annotation or setting similar to #JsonNaming?
Here is my postman data and sample codes.
Debug data: sampleName=name, sampleDesc=null.
// Controller
#RestController
#RequestMapping("/sample")
public class SampleController {
#Autowired
private SampleService sampleService;
#GetMapping
public Result getSampleList(SampleDTO param) throws Exception {
return sampleService.getFolderList(param);
}
#PostMapping
public Result insertSample(#RequestBody SampleDTO param) throws Exception {
// this method works well with #JsonNaming
return sampleService.insertFolder(param);
}
}
// DTO
#Setter
#Getter
#NoArgsConstructor
#JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
#Alias("SampleDTO")
public class SampleDTO {
#NotNull
private Long sampleNo;
#NotBlank
private String sampleName;
private String sampleDesc;
#Builder
public SampleDTO(Long sampleNo, String sampleName, String sampleDesc) {
this.sampleNo = sampleNo;
this.sampleName = sampleName;
this.sampleDesc = sampleDesc;
}
}
I had the same problem and didn't find an annotation for this but maybe you can use #ConstructorProperties like this in your DTO's constructor:
#ConstructorProperties({"sample_no","sample_name","sample_desc"})
public SampleDTO(Long sampleNo, String sampleName, String sampleDesc) {
this.sampleNo = sampleNo;
this.sampleName = sampleName;
this.sampleDesc = sampleDesc;
}
I have a Spring Boot Controller -
#RestController
public class UserController {
#PostMapping
#ResponseStatus(CREATED)
public UserResponse register( #Valid #RequestBody UserRequest userRequest) {
//return ....
}
}
Below is UserRequest.java
#Data
#NoArgsConstructor
#AllArgsConstructor
#Builder
public class UserRequest {
private String email;
//other property
}
I am sending below json in request body -
{
"email" : "TEST#Example.com",
//some other fields.
}
Sometime client send email in uppercase or in camel case so in userRquest I want to change value of email field to lowercase like test#example.com while de serializing to UserRequest Object.
Is there any easy way to do this. Can I introduce my own annotation like #ToLowerCase how I can create my own annotation and use that at field level in UserRequest.
There is no easy way just by introducing a new annotation #ToLowerCase,
because then you would also need to implement some annotation processor
for doing the real conversion work.
But you can achieve your goal in a slightly different way.
In your UserRequest class annotate the email property
with #JsonDeserialize and specify a converter there.
#JsonDeserialize(converter = ToLowerCaseConverter.class)
private String email;
You need to implement the converter class by yourself,
but it is easy by extending it from StdConverter.
public class ToLowerCaseConverter extends StdConverter<String, String> {
#Override
public String convert(String value) {
return value.toLowerCase();
}
}
Jackson will use the setter methods in your class.
Perform the conversion to lower case in the setter.
For example
public void setEmail(String newValue)
{
email = StringUtils.lowerCase(newValue);
}
StringUtils is an apache commons class.
You can make a general StringDeserializer and register it in ObjectMapper as shown below:-
StringDeserializer class
public final class StringDeserializer extends StdDeserializer<String> {
public StringDeserializer() {
super((Class<String>) null);
}
#Override
public String deserialize(JsonParser parser, DeserializationContext context) throws IOException {
JsonToken token = parser.getCurrentToken();
if (token == JsonToken.VALUE_STRING) {
String text = parser.getText();
return text == null ? null : text.toLowerCase().trim();
}
return null;
}
}
JacksonConfiguration class
#Configuration
public class JacksonConfiguration {
#Autowired
void mapper(ObjectMapper mapper) {
mapper.registerModule(initModule());
}
private Module initModule() {
SimpleModule module = new SimpleModule();
module.addDeserializer(String.class, new StringDeserializer());
return module;
}
}
The above code makes jackson deserialize all strings to lowercase and trimmed.
I have a simple service behind a REST controller in Spring Boot. The service is a singleton (by default) and I am autowiring a session-scoped bean component used for storing session preferences information and attempting to populate its values from the service. I call setters on the autowired component, but the fields I am setting stay null and aren't changed.
Have tried with and without Lombok on the bean; also with and without implementing Serializable on FooPref; also copying properties from FooPrefs to another DTO and returning it; also injecting via #Autowired as well as constructor injection with #Inject. The fields stay null in all of those cases.
Running Spring Boot (spring-boot-starter-parent) 1.5.6.RELEASE, Java 8, with the spring-boot-starter-web.
Session-scoped component:
#Component
#SessionScope(proxyMode = ScopedProxyMode.TARGET_CLASS)
#Data
#NoArgsConstructor
public class FooPrefs implements Serializable {
private String errorMessage;
private String email;
private String firstName;
private String lastName;
}
REST Controller:
#RestController
#RequestMapping("/api/foo")
public class FooController {
#Autowired
private FooPrefs fooPrefs;
private final FooService fooService;
#Inject
public FooController(FooService fooService) {
this.fooService = fooService;
}
#PostMapping(value = "/prefs", consumes = "application/json", produces = "application/json")
public FooPrefs updatePrefs(#RequestBody Person person) {
fooService.updatePrefs(person);
// These checks are evaluating to true
if (fooPrefs.getEmail() == null) {
LOGGER.error("Email is null!!");
}
if (fooPrefs.getFirstName() == null) {
LOGGER.error("First Name is null!!");
}
if (fooPrefs.getFirstName() == null) {
LOGGER.error("First Name is null!!");
}
return fooPrefs;
}
}
Service:
#Service
#Scope(value = "singleton")
#Transactional(readOnly = true)
public class FooService {
#Autowired
private FooPrefs fooPrefs;
#Inject
public FooService(FooRepository fooRepository) {
this.fooRepository = fooRepository;
}
public void updatePrefs(Person person) {
fooRepository.updatePerson(person);
//the fields below appear to getting set correctly while debugging in the scope of this method call but after method return, all values on fooPrefs are null
fooPrefs.setEmail(person.getEmail());
fooPrefs.setFirstName(person.getFirstName());
fooPrefs.setLastName(person.getLastName());
}
}
I discovered my problem. Fields were being added to my FooPrefs session-managed object and were breaking my client. The setters were actually working and being nulled out by some error handling code.
Edits per below fixed the JSON serialization problems:
Session-scoped component (no change)
New Dto
#Data
#NoArgsConstructor
public class FooPrefsDto {
private String errorMessage;
private String email;
private String firstName;
private String lastName;
}
Controller (updated)
#RestController
#RequestMapping("/api/foo")
public class FooController {
private final FooService fooService;
#Inject
public FooController(FooService fooService) {
this.fooService = fooService;
}
#PostMapping(value = "/prefs", consumes = "application/json", produces = "application/json")
public FooPrefsDto updatePrefs(#RequestBody Person person) {
FooPrefsDto result = fooService.updatePrefs(person);
// results coming back correctly now
if (result.getEmail() == null) {
LOGGER.error("Email is null!!");
}
if (result.getFirstName() == null) {
LOGGER.error("First Name is null!!");
}
if (result.getFirstName() == null) {
LOGGER.error("First Name is null!!");
}
return result;
}
}
Service (updated)
#Service
#Scope(value = "singleton")
#Transactional(readOnly = true)
public class FooService {
#Autowired
private FooPrefs fooPrefs;
#Inject
public FooService(FooRepository fooRepository) {
this.fooRepository = fooRepository;
}
public FooPrefsDto updatePrefs(Person person) {
fooRepository.updatePerson(person);
//the fields below appear to getting set correctly while debugging in the scope of this method call but after method return, all values on fooPrefs are null
fooPrefs.setEmail(person.getEmail());
fooPrefs.setFirstName(person.getFirstName());
fooPrefs.setLastName(person.getLastName());
return getFooPrefsDto();
}
private FooPrefsDto getFooPrefsDto() {
FooPrefsDto retDto = new FooPrefsDto();
retDto.setEmail(fooPrefs.getEmail());
retDto.setLastName(fooPrefs.getLastName());
retDto.setFirstName(fooPrefs.getFirstName());
return retDto;
}
}
I am trying to connect to my external ElasticSearch server with Spring Boot.
If I do a curl from command line, I get expected results.
curl "http://ipAddr:9200/indexName/TYPE/_search?pretty=true"
But getting this error when I try to access it via Spring Boot.
<html><body><h1>Whitelabel Error Page</h1><p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p><div id='created'>Mon Sep 11 12:39:15 IST 2017</div><div>There was an unexpected error (type=Internal Server Error, status=500).</div><div>Could not write JSON: (was java.lang.NullPointerException); nested exception is com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.NullPointerException) (through reference chain: java.util.ArrayList[0]->org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl["facets"])</div></body></html>
Not sure why a NullPointerException and what is aggregartion.impl
Here is my Spring Application:
Controller:
#RestController
public class PojoController {
#Autowired
PojoService pojoService;
#RequestMapping(value = "/", method=RequestMethod.GET)
public #ResponseBody String index() {
return new String("Welcome:)");
}
#RequestMapping(value = "/all", method = RequestMethod.GET,
produces = { MediaType.APPLICATION_JSON_VALUE })
#ResponseBody List<POJO> findAll() {
try {
List<POJO> pojoObj = pojoService.findAll();
return pojoObj;
} catch (Exception exp) {
exp.printStackTrace();
return null;
}
}
}
Repository:
#Repository
public interface PojoRepository extends ElasticsearchRepository<POJO, Integer> {
List<POJO> findAll();
}
Service:
#Service
public class POJOServiceImpl implements POJOService{
private POJORepository pojoRepository;
private ElasticsearchTemplate elasticsearchTemplate;
#Autowired
public void setPojoRepository(PojoRepository pojoRepository) {
this.pojoRepository = pojoRepository;
}
public POJO findOne(String id) {
return pojoRepository.findOne(id);
}
public List<POJO> findAll() {
return (List<POJO>) pojoRepository.findAll();
}
}
POJO class:
#Document(indexName = "INDEX", type = "TYPE")
public class POJO {
#Id
private Integer id;
private String name;
public POJO(){
// empty
}
public POJO(Integerid, String name) {
super();
this.id = id;
this.name = name;
}
// getters and setters
}
I should be able to query all the documents in the index. Later on, I will try and use filters etc.
Any help is appreciated. Thanks :)
It looks like Jackson has a problem with handling your POJO (probably related to this issue: DATAES-274) - the problematic part is casting in repository from Iterable collection to List.
Update
In case of repositories, spring-data-elasticsearch behaves a bit different than you would expect. Taking your example:
#Repository
public interface PojoRepository extends ElasticsearchRepository<POJO, Integer> {
List<POJO> findAll();
}
and after calling in your rest controller:
List<POJO> pojoObj = pojoService.findAll();
in debugger you will see something like this:
You would expect that pojoObj list contains objects of POJO class.
And here comes the surprise - pojoObj ArrayList contains one object of AggregatedPageImpl type and its content field is the right list that contains your POJO objects.
This is the reason why you get:
Could not write JSON: ... java.util.ArrayList[0]->org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl[\"facets\"])
As I wrote before, Jackson cannot handle this while serializing POJO objects.
Solution 1
Let repositories return Iterable collection (by default).
#Repository
public interface PojoRepository extends ElasticsearchRepository<POJO, Integer> {
}
Move the conversion part to the service but use some utility method (here with Guava) in order to have it like this:
import com.google.common.collect.Lists;
public List<POJO> findAll() {
return Lists.newArrayList(pojoRepository.findAll());
}
Solution 2
Use Page in repository (here simplified version without parameters):
#Repository
public interface PojoRepository extends ElasticsearchRepository<POJO, Integer> {
Page<TestDto> findAll();
}
If you still want to operate on list - get content from page in service:
public List<POJO> findAll() {
return testDtoRepository.findAll().getContent();
}
I can't get Spring Data Rest with class inheritance working.
I'd like to have a single JSON Endpoint which handles all my concrete classes.
Repo:
public interface AbstractFooRepo extends KeyValueRepository<AbstractFoo, String> {}
Abstract class:
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
#JsonSubTypes({
#JsonSubTypes.Type(value = MyFoo.class, name = "MY_FOO")
})
public abstract class AbstractFoo {
#Id public String id;
public String type;
}
Concrete class:
public class MyFoo extends AbstractFoo { }
Now when calling POST /abstractFoos with {"type":"MY_FOO"}, it tells me: java.lang.IllegalArgumentException: PersistentEntity must not be null!.
This seems to happen, because Spring doesn't know about MyFoo.
Is there some way to tell Spring Data REST about MyFoo without creating a Repository and a REST Endpoint for it?
(I'm using Spring Boot 1.5.1 and Spring Data REST 2.6.0)
EDIT:
Application.java:
#SpringBootApplication
#EnableMapRepositories
public class Application {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
I'm using Spring Boot 1.5.1 and Spring Data Release Ingalls.
KeyValueRepository doesn't work with inheritance. It uses the class name of every saved object to find the corresponding key-value-store. E.g. save(new Foo()) will place the saved object within the Foo collection. And abstractFoosRepo.findAll() will look within the AbstractFoo collection and won't find any Foo object.
Here's the working code using MongoRepository:
Application.java
Default Spring Boot Application Starter.
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
AbstractFoo.java
I've tested include = JsonTypeInfo.As.EXISTING_PROPERTY and include = JsonTypeInfo.As.PROPERTY. Both seem to work fine!
It's even possible to register the Jackson SubTypes with a custom JacksonModule.
IMPORTANT: #RestResource(path="abstractFoos") is highly recommended. Else the _links.self links will point to /foos and /bars instead of /abstractFoos.
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type")
#JsonSubTypes({
#JsonSubTypes.Type(value = Foo.class, name = "MY_FOO"),
#JsonSubTypes.Type(value = Bar.class, name = "MY_Bar")
})
#Document(collection="foo_collection")
#RestResource(path="abstractFoos")
public abstract class AbstractFoo {
#Id public String id;
public abstract String getType();
}
AbstractFooRepo.java
Nothing special here
public interface AbstractFooRepo extends MongoRepository<AbstractFoo, String> { }
Foo.java & Bar.java
#Persistent
public class Foo extends AbstractFoo {
#Override
public String getType() {
return "MY_FOO";
}
}
#Persistent
public class Bar extends AbstractFoo {
#Override
public String getType() {
return "MY_BAR";
}
}
FooRelProvider.java
Without this part, the output of the objects would be separated in two arrays under _embedded.foos and _embedded.bars.
The supports method ensures that for all classes which extend AbstractFoo, the objects will be placed within _embedded.abstractFoos.
#Component
#Order(Ordered.HIGHEST_PRECEDENCE)
public class FooRelProvider extends EvoInflectorRelProvider {
#Override
public String getCollectionResourceRelFor(final Class<?> type) {
return super.getCollectionResourceRelFor(AbstractFoo.class);
}
#Override
public String getItemResourceRelFor(final Class<?> type) {
return super.getItemResourceRelFor(AbstractFoo.class);
}
#Override
public boolean supports(final Class<?> delimiter) {
return AbstractFoo.class.isAssignableFrom(delimiter);
}
}
EDIT
Added #Persistent to Foo.java and Bar.java. (Adding it to AbstractFoo.java doesn't work). Without this annotation I got NullPointerExceptions when trying to use JSR 303 Validation Annotations within inherited classes.
Example code to reproduce the error:
public class A {
#Id public String id;
#Valid public B b;
// #JsonTypeInfo + #JsonSubTypes
public static abstract class B {
#NotNull public String s;
}
// #Persistent <- Needed!
public static class B1 extends B { }
}
Please see the discussion in this resolved jira task for details of what is currently supported in spring-data-rest regarding JsonTypeInfo. And this jira task on what is still missing.
To summarize - only #JsonTypeInfo with include=JsonTypeInfo.As.EXISTING_PROPERTY is working for serialization and deserialization currently.
Also, you need spring-data-rest 2.5.3 (Hopper SR3) or later to get this limited support.
Please see my sample application - https://github.com/mduesterhoeft/spring-data-rest-entity-inheritance/tree/fixed-hopper-sr3-snapshot
With include=JsonTypeInfo.As.EXISTING_PROPERTY the type information is extracted from a regular property. An example helps getting the point of this way of adding type information:
The abstract class:
#Entity #Inheritance(strategy= SINGLE_TABLE)
#JsonTypeInfo(use=JsonTypeInfo.Id.NAME,
include=JsonTypeInfo.As.EXISTING_PROPERTY,
property="type")
#JsonSubTypes({
#Type(name="DECIMAL", value=DecimalValue.class),
#Type(name="STRING", value=StringValue.class)})
public abstract class Value {
#Id #GeneratedValue(strategy = IDENTITY)
#Getter
private Long id;
public abstract String getType();
}
And the subclass:
#Entity #DiscriminatorValue("D")
#Getter #Setter
public class DecimalValue extends Value {
#Column(name = "DECIMAL_VALUE")
private BigDecimal value;
public String getType() {
return "DECIMAL";
}
}