We Keep Coding

Parse headers information and set it in bean

In my spring rest application I need to read the headers information for PUT and POST calls and set those information in the bean passed as #RequestBody. currently what am doing is like follows.
#RequestMapping(value = "/create", method = RequestMethod.POST)
#ResponseStatus(value = HttpStatus.OK)
#ResponseBody
public ReportRepresentation createDailyReport(#RequestBody ReportEntity reportEntity,
#RequestHeader(value= "FIRST_HEAD1", required = false) boolean isHeaderSet,
#RequestHeader(value= "SECOND_HEAD2", required = false) Long scondHead) {
// Setting the header values into bean properties .
}
So am extracting the headers in all methods(POST and PUT) and setting values in different entities.
My question is is there any way to parse/ override the #RequestBody in method param in global level and set those headers?

You can use RequestBodyAdvice:
For example:
Bean:
#Data
public class MyBean {
private String property;
}
Controller:
#RestController
public class MyController {
#RequestMapping("/")
public MyBean get(#RequestBody MyBean myBean) {
return myBean;
}
}
Advisor:
#ControllerAdvice(annotations = RestController.class)
public class MyRequestBodyAdvisor extends RequestBodyAdviceAdapter {
#Override
public boolean supports(MethodParameter methodParameter, Type type, Class<? extends HttpMessageConverter<?>> aClass) {
return methodParameter.getParameterType() == MyBean.class;
}
#Override
public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType, Class<? extends HttpMessageConverter<?>> converterType) {
MyBean myBean = (MyBean)body;
List<String> strings = inputMessage.getHeaders().get("X-Property");
myBean.setProperty(strings.get(0));
return myBean;
}
}
Testing:
$ curl localhost:8080 -d '{}' -X POST -H 'X-Property: myProp' -H 'Content-Type: application/json' -s
Output:
{"property":"myProp"}

I have implemented the same as #caco3 mentioned here is my implementation with set the values to bean.
#ControllerAdvice
public class RequestBodyAdviceChain implements RequestBodyAdvice {
.. Other methods
#Override
public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
Class<? extends HttpMessageConverter<?>> converterType) {
HttpHeaders headers = inputMessage.getHeaders();
List<String> emulated = headers.get("FIRST_HEAD1");
Boolean isEmulated = false;
Long emulatedUserId = null;
if (!CollectionUtils.isEmpty(emulated)) {
isEmulated = Boolean.valueOf(emulated.get(0));
}
if (isEmulated) {
List<String> users = headers.get("SECOND_HEAD2");
if (!CollectionUtils.isEmpty(users)) {
emulatedUserId = Long.valueOf(users.get(0));
}
}
if (isEmulated) {
if (setField(body, Is_Emulated_Field, isEmulated)) {
setField(body, EmulatedUserId_FIELD, emulatedUserId);
}
}
return body;
}
/**
* <p>
* Method to set the field value for the emulated user and it's id wven
* though if the fields are defined in the super class.
*/
private static boolean setField(Object targetObject, String fieldName, Object fieldValue) {
Field field;
try {
field = targetObject.getClass().getDeclaredField(fieldName);
} catch (NoSuchFieldException e) {
field = null;
}
Class superClass = targetObject.getClass().getSuperclass();
while (field == null && superClass != null) {
try {
field = superClass.getDeclaredField(fieldName);
} catch (NoSuchFieldException e) {
superClass = superClass.getSuperclass();
}
}
if (field == null) {
return false;
}
field.setAccessible(true);
try {
field.set(targetObject, fieldValue);
return true;
} catch (IllegalAccessException e) {
return false;
}
}
}

#RequestBody #Valid SomeDTO has field of enum type, custom error message

I have the following #RestController
#RequestMapping(...)
public ResponseEntity(#RequestBody #Valid SomeDTO, BindingResult errors) {
//do something with errors if validation error occur
}
public class SomeDTO {
public SomeEnum someEnum;
}
If the JSON request is { "someEnum": "valid value" }, everything works fine. However, if the request is { "someEnum": "invalid value" }, it only return error code 400.
How can I trap this error so I can provide a custom error message, such as "someEnum must be of value A/B/C".

The answer provided by #Amit is good and works. You can go ahead with that if you want to deserialize an enum in a specific way. But that solution is not scalable. Because every enum which needs validation must be annotated with #JsonCreator.
Other answers won't help you beautify the error message.
So here's my solution generic to all the enums in spring web environment.
#RestControllerAdvice
public class ControllerErrorHandler extends ResponseEntityExceptionHandler {
public static final String BAD_REQUEST = "BAD_REQUEST";
#Override
public ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException exception,
HttpHeaders headers, HttpStatus status, WebRequest request) {
String genericMessage = "Unacceptable JSON " + exception.getMessage();
String errorDetails = genericMessage;
if (exception.getCause() instanceof InvalidFormatException) {
InvalidFormatException ifx = (InvalidFormatException) exception.getCause();
if (ifx.getTargetType()!=null && ifx.getTargetType().isEnum()) {
errorDetails = String.format("Invalid enum value: '%s' for the field: '%s'. The value must be one of: %s.",
ifx.getValue(), ifx.getPath().get(ifx.getPath().size()-1).getFieldName(), Arrays.toString(ifx.getTargetType().getEnumConstants()));
}
}
ErrorResponse errorResponse = new ErrorResponse();
errorResponse.setTitle(BAD_REQUEST);
errorResponse.setDetail(errorDetails);
return handleExceptionInternal(exception, errorResponse, headers, HttpStatus.BAD_REQUEST, request);
}
}
This will handle all the invalid enum values of all types and provides a better error message for the end user.
Sample output:
{
"title": "BAD_REQUEST",
"detail": "Invalid enum value: 'INTERNET_BANKING' for the field: 'paymentType'. The value must be one of: [DEBIT, CREDIT]."
}

#ControllerAdvice
public static class GenericExceptionHandlers extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException e, HttpHeaders headers, HttpStatus status, WebRequest request) {
return new ResponseEntity<>(new ErrorDTO().setError(e.getMessage()), HttpStatus.BAD_REQUEST);
}
}
I created a fully functional Spring boot Application with a Test on Bitbucket

You do not need #Valid for enum validation, you can achieve the required response using below code:
Controller Code, StackDTO has an enum PaymentType in it:
#RequestMapping(value = "/reviews", method = RequestMethod.POST)
#ResponseBody
public ResponseEntity<String> add(#RequestBody StackDTO review) {
return new ResponseEntity<String>(HttpStatus.ACCEPTED);
}
Create an exception class, as EnumValidationException
public class EnumValidationException extends Exception {
private String enumValue = null;
private String enumName = null;
public String getEnumValue() {
return enumValue;
}
public void setEnumValue(String enumValue) {
this.enumValue = enumValue;
}
public String getEnumName() {
return enumName;
}
public void setEnumName(String enumName) {
this.enumName = enumName;
}
public EnumValidationException(String enumValue, String enumName) {
super(enumValue);
this.enumValue = enumValue;
this.enumName = enumName;
}
public EnumValidationException(String enumValue, String enumName, Throwable cause) {
super(enumValue, cause);
this.enumValue = enumValue;
this.enumName = enumName;
}
}
I have enum as below, with a special annotation #JsonCreator on a method create
public enum PaymentType {
CREDIT("Credit"), DEBIT("Debit");
private final String type;
PaymentType(String type) {
this.type = type;
}
String getType() {
return type;
}
#Override
public String toString() {
return type;
}
#JsonCreator
public static PaymentType create (String value) throws EnumValidationException {
if(value == null) {
throw new EnumValidationException(value, "PaymentType");
}
for(PaymentType v : values()) {
if(value.equals(v.getType())) {
return v;
}
}
throw new EnumValidationException(value, "PaymentType");
}
}
Finally RestErrorHandler class,
#ControllerAdvice
public class RestErrorHandler {
#ExceptionHandler(HttpMessageNotReadableException.class)
#ResponseStatus(HttpStatus.BAD_REQUEST)
#ResponseBody
public ResponseEntity<ValidationErrorDTO> processValidationIllegalError(HttpMessageNotReadableException ex,
HandlerMethod handlerMethod, WebRequest webRequest) {
EnumValidationException exception = (EnumValidationException) ex.getMostSpecificCause();
ValidationErrorDTO errorDTO = new ValidationErrorDTO();
errorDTO.setEnumName(exception.getEnumName());
errorDTO.setEnumValue(exception.getEnumValue());
errorDTO.setErrorMessage(exception.getEnumValue() + " is an invalid " + exception.getEnumName());
return new ResponseEntity<ValidationErrorDTO>(errorDTO, HttpStatus.BAD_REQUEST);
}
}
ValidationErrorDTO is the dto with setters/getters of enumValue, enumName and errorMessage. Now when you send POST call to controller endpoint /reviews with below request
{"paymentType":"Credit2"}
Then code returns response as 400 with below response body -
{
"enumValue": "Credit2",
"enumName": "PaymentType",
"errorMessage": "Credit2 is an invalid PaymentType"
}
Let me know if it resolves your issue.

Yon can achieve this using #ControllerAdvice as follows
#org.springframework.web.bind.annotation.ExceptionHandler(value = {InvalidFormatException.class})
public ResponseEntity handleIllegalArgumentException(InvalidFormatException exception) {
return ResponseEntity.badRequest().body(exception.getMessage());
}
Basically , the idea is to catch com.fasterxml.jackson.databind.exc.InvalidFormatException and handle it as per your requirement.

#Valid has to do with Hibernate bean validation. Currently enum type is not supported out of the box. I found this answer to be the closet, https://funofprograming.wordpress.com/2016/09/29/java-enum-validator/, the drawback however is that you have to make the enum field of type String instead.

Spring Boot JPA - paging and sorting

I am trying to implement pagination to my Spring Data JPA repository in Spring Boot but I am stuck with the following exception when running uni tests:
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.domain.Pageable]: Specified class is an interface
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
...
Could someone point out to me what am I missing here? This is my repository:
#Repository
public interface VenueRepository extends PagingAndSortingRepository<Venue, Long> {
public Page<Venue> findAll(Pageable pageable);
}
and controller:
#RestController
#RequestMapping("/venues")
public class VenueController {
#Autowired
private VenueRepository venueRepo;
#RequestMapping(method = RequestMethod.GET)
public ResponseEntity<Page<Venue>> getVenues(Pageable pageable) {
return new ResponseEntity<>(venueRepo.findAll(pageable), HttpStatus.OK);
}
}
and finally my test:
#Test
public void responseOkVenuesTest() throws Exception {
mvc.perform(get("/venues").accept(MediaType.APPLICATION_JSON_VALUE)).andExpect(status().isOk());
}
I spent couple of hours trying to make this work and am running out of ideas. Thank you for any tips!

Change your method getVenues in the way that you can pass the parameters to instantiate a PageRequest instead of passing Pageable :
#RequestMapping(method = RequestMethod.GET)
public ResponseEntity<List<Venue>> getVenues(int from,int to) {
return new ResponseEntity<>(
venueRepo.findAll((new PageRequest(from, to)), HttpStatus.OK).getContent();
}

In addition to #SEY_91's answer you might also like to use the following solution inspired with How to remove redundant Spring MVC method by providing POST-only #Valid? and used in my Spring Boot-driven application for long time.
In short, here is an annotation to annotate controller method parameters:
#Target(PARAMETER)
#Retention(RUNTIME)
public #interface PlainModelAttribute {
}
Now, just a method processor that would scan for parameters annotated with #PlainModelAttribute:
public final class PlainModelAttributeMethodProcessor
extends ModelAttributeMethodProcessor {
private final Map<TypeToken<?>, Converter<? super NativeWebRequest, ?>> index;
private PlainModelAttributeMethodProcessor(final Map<TypeToken<?>, Converter<? super NativeWebRequest, ?>> index) {
super(true);
this.index = index;
}
public static HandlerMethodArgumentResolver plainModelAttributeMethodProcessor(final Map<TypeToken<?>, Converter<? super NativeWebRequest, ?>> index) {
return new PlainModelAttributeMethodProcessor(index);
}
#Override
public boolean supportsParameter(final MethodParameter parameter) {
return parameter.hasParameterAnnotation(PlainModelAttribute.class) || super.supportsParameter(parameter);
}
#Override
protected Object createAttribute(final String attributeName, final MethodParameter parameter, final WebDataBinderFactory binderFactory,
final NativeWebRequest request) {
final TypeToken<?> typeToken = TypeToken.of(parameter.getGenericParameterType());
final Converter<? super NativeWebRequest, ?> converter = index.get(typeToken);
if ( converter == null ) {
throw new IllegalArgumentException("Cannot find a converter for " + typeToken.getType());
}
return converter.convert(request);
}
#Override
protected void bindRequestParameters(final WebDataBinder binder, final NativeWebRequest request) {
final HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class);
if ( !isSafe(resolve(servletRequest.getMethod())) ) {
((ServletRequestDataBinder) binder).bind(servletRequest);
}
}
private static HttpMethod resolve(final String name) {
return HttpMethod.valueOf(name.toUpperCase());
}
private static boolean isSafe(final HttpMethod method)
throws UnsupportedOperationException {
switch ( method ) {
case GET:
case HEAD:
case OPTIONS:
return true;
case POST:
case PUT:
case PATCH:
case DELETE:
return false;
case TRACE:
throw new UnsupportedOperationException();
default:
throw new AssertionError(method);
}
}
}
I don't really remember, but a resolve() method equivalent should be present in Spring Framework somewhere. Note that I use Google Guava TypeToken in order to let the processor be compatible with generic types (since I use models like IQuery<Foo> and IQuery<Bar> in controllers). Now just register the processor:
#Configuration
#EnableWebMvc
public class MvcConfiguration
extends WebMvcConfigurerAdapter {
#Override
public void addArgumentResolvers(final List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(createModelAttributeMethodProcessor());
}
private static HandlerMethodArgumentResolver createModelAttributeMethodProcessor() {
return plainModelAttributeMethodProcessor(ImmutableMap.of(pageableTypeToken, MvcConfiguration::toPageable));
}
private static final TypeToken<Pageable> pageableTypeToken = new TypeToken<Pageable>() {
};
private static Pageable toPageable(final WebRequest request) {
return new PageRequest(
ofNullable(request.getParameter("page")).map(Integer::parseInt).orElse(0),
ofNullable(request.getParameter("size")).map(Integer::parseInt).orElse(1)
);
}
}
Here is a web request to a Pageable DTO conversion, and the converter must be registered as an argument resolver. So now it's ready to use:
#RestController
#RequestMapping("/")
public class Controller {
#RequestMapping(method = GET)
public String get(#PlainModelAttribute final Pageable pageable) {
return toStringHelper(pageable)
.add("offset", pageable.getOffset())
.add("pageNumber", pageable.getPageNumber())
.add("pageSize", pageable.getPageSize())
.add("sort", pageable.getSort())
.toString();
}
}
A few examples:
/ ⇒ PageRequest{offset=0, pageNumber=0, pageSize=1, sort=null}
/?page=43 ⇒ PageRequest{offset=43, pageNumber=43, pageSize=1, sort=null}
/?size=32 ⇒ PageRequest{offset=0, pageNumber=0, pageSize=32, sort=null}
/?page=22&size=32 ⇒ PageRequest{offset=704, pageNumber=22, pageSize=32, sort=null}

Generics overloading of method - workaround

this question was asked many times but I couldn't find elegant workaround for it.
This example works as desired:
public class RequestWrapper<T> {
private final T request;
private final Class<T> type;
public RequestWrapper(T request, Class<T> type) {
this.request = request;
this.type = type;
}
public T getRequest() {
return request;
}
public Class<T> getType() {
return type;
}
}
public class Service {
private void invoke(String request) {
System.out.println("String:" + request);
}
private void invoke(Object request) {
System.out.println("Object:" + request + "," + request.getClass().getSimpleName());
}
public static void main(String[] args) {
RequestWrapper<String> sw = new RequestWrapper<String>("A", String.class);
RequestWrapper<Integer> iw = new RequestWrapper<Integer>(Integer.valueOf(0), Integer.class);
new Service().invoke(sw.getRequest());
new Service().invoke(iw.getRequest());
}
}
But I would need to add one more method to Service class which do something before/after call of invoke method:
public void invoke(RequestWrapper<?> wrapper) {
try {
// ...
invoke(wrapper.getType().cast(wrapper.getRequest()));
invoke(wrapper.getRequest());
} catch(Exception e ) {
// ...
}
}
then the main method would contain:
new Service().invoke(sw);
I understand the reason why the invoke(Object request) is used instead of invoke(String request).
What would be an elegant solution to call proper invoke method and be able to do some common actions before/after it?
To have an interface e.g. Invoker, implement it e.g. StringInvoker, Invoker> and call map.get(wrapper.getType()).invoke(wrapper.getRequest()) is possible solution but I expect something better.

You can check the type and explicitly cast it, for example (I also added Integer so you can see branching on more types):
Class<?> c = wrapper.getType();
if (c == String.class)
invoke((String) wrapper.getRequest()); // Invokes invoke(String)
else if (c == Integer.class)
invoke((Integer) wrapper.getRequest()); // Invokes invoke(Integer)
else
invoke(wrapper.getRequest()); // Invokes invoke(Object)
Note:
If you go on this path, you don't even need to store the request type in the RequestWrapper class because you can just as easily use the instanceof operator on the request itself to check its type. And if you "get rid" of the request type, your current RequestWrapper class will only contain the request so the RequestWrapper is not even needed in this case.

Visitor patter can serves to solve it. Only drawback is that there isn't possible to write:
new Service().invoke(new RequestWrapper<String>("A"));
My implementation:
public class Service {
public void invoke(RequestWrapper<?> wrapper) {
try {
// ...
wrapper.invoke(this);
} catch(Exception e ) {
// ...
}
}
public void invoke(String request) {
System.out.println("String:" + request);
}
public void invoke(Boolean request) {
System.out.println("Boolean:" + request);
}
public static void main(String[] args) {
RequestWrapper<Boolean> rw = new BooleanRequestWrapper(Boolean.TRUE);
new Service().invoke(rw);
}
}
abstract class RequestWrapper<T> {
protected final T request;
public RequestWrapper(T request) {
this.request = request;
}
public abstract void invoke(Service v);
}
class BooleanRequestWrapper extends RequestWrapper<Boolean> {
public BooleanRequestWrapper(Boolean request) {
super(request);
}
public void invoke(Service service) {
service.invoke(request);
}
}

RESTeasy InMemoryClient does not inject #Context UriInfo field into Spring #Transactional Bean

We have a problem with our tests that the field UriInfo is not correctly injected when the resource is wrapped in a TransactionalProxy.
We tried using the SpringResourceFactory but that did not help either.
I tried to extract the relevant classes for this usecase:
public class InMemoryClientFactory implements FactoryBean<InMemoryClientExecutor>{
#Inject
private SessionResource sessionResource;
#Override
public InMemoryClientExecutor getObject() throws Exception {
Dispatcher dispatcher = MockDispatcherFactory.createDispatcher();
Registry registry = dispatcher.getRegistry();
registry.addSingletonResource(sessionResource);
final InMemoryClientExecutor inMemoryClientExecutor = new InMemoryClientExecutor(dispatcher);
}
#Override
public Class getObjectType() {
return InMemoryClientExecutor.class;
}
#Override
public boolean isSingleton() {
return true;
}
}
#Path("session")
public interface SessionResource {
#GET
#Path("{sessionId}")
#Produces({MediaType.APPLICATION_XML})
Response get(#PathParam("sessionId") String sessionId);
#DELETE
#Path("{sessionId}")
Response delete(#PathParam("sessionId") String sessionId);
}
#Service
#Transactional
public class SessionResourceImpl implements SessionResource {
#Context
private UriInfo uriInfo;
#Override
public Response get(String sessionId) {
// uriInfo will be null here
String url = uriInfo.getBaseUriBuilder().path(SessionResource.class).path(SessionResource.class, "delete").build(sessionId)
.toString());
return Response.ok(session).build();
#Override
public Response delete(String sessionId) {
System.out.println("Deleted Session "+1);
}
}
#ContextConfiguration(locations = ["classpath:/META-INF/testContext.xml"])
#Transactional
#RunWith(SpringJUnit4ClassRunner.class)
public class SessionResourceIT {
#Inject
InMemoryRestClientFactory inMemoryClientFactory;
#Inject
SessionResource resource;
#Test
public void test() {
SessionResource resource = inMemoryClientFactory.createProxy(SessionResource.class);
ClientResponse cr = client.get(sessionId);
assertNotNull(cr.getEntity(String.class));
}
}

A possible workaround is to unwrap the transactional proxy for the tests, this works as long as the test itself is annotated with #Transactional. I hope someone has a better solution than this.
public class InMemoryClientFactory implements FactoryBean<InMemoryClientExecutor>{
#Inject
private SessionResource sessionResource;
#Override
public InMemoryClientExecutor getObject() throws Exception {
Dispatcher dispatcher = MockDispatcherFactory.createDispatcher();
Registry registry = dispatcher.getRegistry();
registry.addSingletonResource(unwrapProxy(sessionResource));
final InMemoryClientExecutor inMemoryClientExecutor = new InMemoryClientExecutor(dispatcher);
}
#Override
public Class getObjectType() {
return InMemoryClientExecutor.class;
}
#Override
public boolean isSingleton() {
return true;
}
private static Object unwrapProxy(Object bean) throws Exception {
Object result = bean;
/*
* If the given object is a proxy, set the return value as the object
* being proxied, otherwise return the given object.
*/
if (AopUtils.isAopProxy(bean) && bean instanceof Advised) {
Advised advised = (Advised) bean;
result = advised.getTargetSource().getTarget();
}
return result;
}
}