question on how to junit test using Mockito forEach in Java8 - junit

I have the below method and I need to unit test it using JUNIT and Mockito. I am confused how to test the foreach method which returns void.
public List<Data> extractOutPutResponse(List<SearchHit> searchHits) {
List<Data> outputData = new ArrayList<>();
Gson gson = new Gson();
searchHits.forEach(hit -> outputData.add(gson.fromJson(hit.getSourceAsString(), Data.class)));
return outputData;
}

Related

Jakson custom serializer for list of objects

I have a custom jackson serializer, and it works for serializing single pojos. Im trying to serialize a list of objects. Without the custom serializer I can just do:
public List<Sale> getAllSales() {
return saleRepository.getAll();
}
which works fine, but I want to return a very specific set of data, so I made a custom serializer, which also works but only for single objects:
public Sale getSale(int id) {
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(Sale.class, new SaleSerializer());
mapper.registerModule(module);
Sale sale = saleRepository.findById(1).orElse(null);
return mapper.writeValueAsString(sale);
}
How do I do the implement the custom serializer for a list of objects?
I'm not sure if this is the best way to do this, but I ended up doing it this way.
public ArrayNode getAllSalesToday() throws JsonProcessingException {
LocalDate localDate = LocalDate.now();
LocalDateTime startOfDay = localDate.atStartOfDay();
LocalDateTime endOfDay = localDate.atTime(LocalTime.MAX);
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(Sale.class, new SaleSerializer());
mapper.registerModule(module);
List<Sale> saleList = saleRepository.getAllByInitialDepositDateIsBetween(startOfDay,endOfDay);
ArrayNode arrayNode = mapper.createArrayNode();
for (Sale sale: saleList){
String x = mapper.writeValueAsString(sale);
JsonNode jsonNode = mapper.readTree(x);
arrayNode.add(jsonNode);
}
return arrayNode;
}

How to test a Datastream with jsonobject in Apache Flink

I am new to testing and i am trying to write a unit test cases on a Flink Datastream which takes input a jsonobject and passes the json object to a processfuntion and it returns a valid or invalid jsonobject when certain rule conditions are met below is the junit test case, below i am trying to compare the output jsonobject from process function with the jsonobject of the input file
#Test
public void testcompareInputAndOutputDataJSONSignal() throws Exception {
org.json.JSONObject jsonObject = toJsonObject();
String input = jsonObject.toString();
String output = JSONDataStreamOutput();
assertEquals(mapper.readTree(input), mapper.readTree(output));
}
below is my toJSONObject and JSONDataStream meathods
public static JSONObject toJsonObject() throws IOException, ParseException {
JSONParser jsonParser = new JSONParser();
FileReader fileReader = new FileReader(getFileFromResources("input.json"));
JSONObject obj = (JSONObject) jsonParser.parse(fileReader);
return obj;
}
public String SignalDataStreamOutput() throws Exception {
final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
DataStream<JSONObject> validSignal = env.fromElements(toJsonObject())
.process(new JsonFilter());
String outputFolder = "output";
validSignal.writeAsText(outputFolder).setParallelism(1);
env.execute();
String content = new String(Files.readAllBytes(Paths.get("output.txt")));
return content;
}
What i am doing is i am converting a jsonfile to jsonobject using the toJSONObject method and sending to a data stream using SignalDataStreamOutput method which will intern send it to a process function in JsonFilter class and validate it against a set of rules and if it's valid it will return a jsonobject and when trying to access the jsonobject directly from stream i am getting value like org.apache.flink#994jdkeiri so i am trying to write the output to a file and trying to read it back to a string and comparing it in test method but this is a work around process and i found a link to use Mockito framework here i changed it to use json object like below
final Collector<JSONObject> collectorMock = (Collector<JSONObject>)Mockito.mock(JsonFilter.class);
final Context contextMock = Mockito.mock(Context.class);
#Test
public void testcompareInputAndOutputDataForValidSignal() throws Exception {
org.json.JSONObject jsonObject = convertToJsonObject();
Mockito.verify(collectorMock).collect(jsonObject);
}
but the above approach is also not working can you suggest me simplified approach to test the json object

Spring HATEOAS with Traverson client and java.time.Instant

Using spring hateoas 1.0.3 with a traverson client is causing problems when the rest-entity has an attribute of type "java.time.Instant".
The error i get is
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `java.time.Instant`
I found that the HttpMessageConverter used inside of the RestTemplate in traverson has only the Jackson2HalModule registered.
Is there a way that i can also register the jackson-modules-java8 module in traverson?
Or is there a way that i can register the Jackson2HalModule in my restTemplate outside of traverson?
Following worked for me in spring-hateoas 1.1.2.RELEASE
private static RestTemplate getRestTemplate() {
List<HttpMessageConverter<?>> httpMessageConverters = SpringFactoriesLoader.loadFactories(TraversonDefaults.class,
Traverson.class.getClassLoader()).get(0).getHttpMessageConverters(Collections.singletonList(MediaTypes.HAL_JSON));
Optional<HttpMessageConverter<?>> first = httpMessageConverters.stream().filter(i -> i instanceof MappingJackson2HttpMessageConverter)
.findFirst();
if (first.isPresent()) {
MappingJackson2HttpMessageConverter httpMessageConverter = (MappingJackson2HttpMessageConverter) first.get();
httpMessageConverter.getObjectMapper().registerModule(new JavaTimeModule());
}
return new RestTemplateBuilder().messageConverters(httpMessageConverters).build();
}
and then using it:
Traverson traverson = new Traverson(URI.create("http://localhost:8080"), MediaTypes.HAL_JSON);
traverson.setRestOperations(getRestTemplate());
After some investigation i found a solution that works for me.
The background is that the traverson client registers a MappingJackson2HttpMessageConverter with contains the Jackson2HalModule.
To fix the problem i had to register also the JavaTimeModule.
I did the following
RestTemplateBuilder genericBuilder = this.restTemplateBuilder
.setConnectTimeout(Duration.ofMillis(configuration.getSecurityRestConnectTimeout()))
.setReadTimeout(Duration.ofMillis(configuration.getSecurityRestReceiveTimeout()));
// my normal restTemplate
RestTemplateBuilder restTemplate = genericBuilder
.defaultMessageConverters()
.build();
// HAL specific restTemplate
RestTemplateBuilder restTemplateHal = genericBuilder
.messageConverters(getHalConverter(Arrays.asList(MediaTypes.HAL_JSON)))
.build();
The HalConverter is generated like this (registering also JavaTimeModule):
private static HttpMessageConverter<?> getHalConverter(List<MediaType> halFlavours) {
ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new Jackson2HalModule());
mapper.registerModule(new JavaTimeModule());
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
converter.setObjectMapper(mapper);
converter.setSupportedMediaTypes(halFlavours);
return converter;
}
Then you can use Traverson in setting the just generated restTemplateHal
Traverson traverson = new Traverson(uri, MediaTypes.HAL_JSON);
traverson.setRestOperations(restTemplateHal);
MyClass myclass = traverson.follow().toObject(MyClass.class);

Create a JSON object to post in Spring Boot tests

I want to write basic test to execute a POST request on a /users URL with JSON payload to create a user. I cannot find how to convert a new object to JSON, and so far have this much, it's obviously wrong but explains the purpose:
#Test public void createUser() throws Exception {
String userJson = new User("My new User", "myemail#gmail.com").toJson();
this.mockMvc.perform(post("/users/").contentType(userJson)).andExpect(status().isCreated());
You can use jackson object mapper and then user writeValueAsString method.
So
#Autowired
ObjectMapper objectMapper;
// or ObjectMapper objectMapper = new ObjectMapper(); this with Spring Boot is useless
#Test public void createUser() throws Exception {
User user = new User("My new User", "myemail#gmail.com");
this.mockMvc.perform(post("/users/")
.contentType(MediaType.APPLICATION_JSON)
.content(objectMapper.writeValueAsString(user)))
.andExpect(status().isCreated());
}
I hope this can help you

How to configure Gson to serialize a set of JSR-303 ConstraintViolation objects?

I can't seem to find out how to serialize Hibernate's implementation of constraint violations using Gson.
Here's what I've tried so far.
Approach 1
MyPojo aPojo = new MyPojo();
Gson gson = new Gson();
Set<ConstraintViolation<MyPojo>> violations = validator.validate(aPojo);
System.out.println(gson.toJson(violations));
Fails with this error:
java.lang.UnsupportedOperationException:
Attempted to serialize java.lang.Class: com.bar.baz.MyPojo.
Forgot to register a type adapter?
at com.google.gson.internal.bind.TypeAdapters$1.write(TypeAdapters.java:67)
at com.google.gson.internal.bind.TypeAdapters$1.write(TypeAdapters.java:61)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.Gson.toJson(Gson.java:593)
at com.google.gson.Gson.toJson(Gson.java:572)
at com.google.gson.Gson.toJson(Gson.java:527)
at com.google.gson.Gson.toJson(Gson.java:507)
Approach 2
Gson gson = new Gson();
Set<ConstraintViolation<MyPojo>> violations = validator.validate(MyPojo);
System.out.println(
gson.toJson(violations,
new TypeToken<ConstraintViolation<MyPojo>>() {}.getType())
);
Fails by not serializing MyPojo's properties:
Output: {}.
Approach 3
I was expecting this approach to delegate serialization to my custom Serializer but it still fails:
GsonBuilder builder = new GsonBuilder();
builder.registerTypeAdapter(
new TypeToken<ConstraintViolation<MyPojo>>() {}.getType(),
new JsonSerializer<ConstraintViolation<MyPojo>>() {
#Override
public JsonElement serialize(ConstraintViolation<MyPojo> src, Type typeOfSrc, JsonSerializationContext context) {
JsonObject result = new JsonObject();
result.addProperty("aTestProperty", "A Test Value");
return result;
}
});
Gson gson = builder.create();
Set<ConstraintViolation<MyPojo>> violations = validator.validate(MyPojo);
System.out.println(gson.toJson(violations));
However it fails with this error:
java.lang.UnsupportedOperationException:
Attempted to serialize java.lang.Class:
com.bar.baz.MyPojo.
Forgot to register a type adapter?
at com.google.gson.internal.bind.TypeAdapters$1.write(TypeAdapters.java:67)
at com.google.gson.internal.bind.TypeAdapters$1.write(TypeAdapters.java:61)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:60)
at com.google.gson.Gson.toJson(Gson.java:593)
at com.google.gson.Gson.toJson(Gson.java:572)
at com.google.gson.Gson.toJson(Gson.java:527)
at com.google.gson.Gson.toJson(Gson.java:507)
Approach 4
Looking at the error message, I though this might work:
GsonBuilder builder = new GsonBuilder();
builder.registerTypeAdapter(
new TypeToken<ConstraintViolation<MyPojo>>() {}.getType(),
new JsonSerializer<ConstraintViolation<MyPojo>>() {
#Override
public JsonElement serialize(ConstraintViolation<MyPojo> src, Type typeOfSrc, JsonSerializationContext context) {
JsonObject result = new JsonObject();
result.addProperty("aTestProperty", "A Test Value");
return result;
}
});
builder.registerTypeAdapter(
new TypeToken<MyPojo>() {}.getType(),
new JsonSerializer<MyPojo>() {
#Override
public JsonElement serialize(MyPojo src, Type typeOfSrc, JsonSerializationContext context) {
JsonObject result = new JsonObject();
result.addProperty("anotherTestProperty", "Another Test Value");
return result;
}
});
Gson gson = builder.create();
Set<ConstraintViolation<MyPojo>> violations = validator.validate(MyPojo);
System.out.println(gson.toJson(violations));
But it fails with a similar error.
Approach 5: Working but ugly
The only thing that I've managed to make work is to register the serializer with the type of the vendor (Hibernate) specific implementation for ConstraintViolation:
Set<ConstraintViolation<MyPojo>> violations = validator.validate(MyPojo);
GsonBuilder builder = new GsonBuilder();
builder.registerTypeAdapter(
new TypeToken<ConstraintViolationImpl>() {}.getType(),
new JsonSerializer<ConstraintViolation<MyPojo>>() {
#Override
public JsonElement serialize(ConstraintViolation<MyPojo> src, Type typeOfSrc, JsonSerializationContext context) {
JsonObject result = new JsonObject();
result.addProperty("aTestProperty", "A Test Value");
return result;
}
});
Gson gson = builder.create();
System.out.println(gson.toJson(violations));
Is there a way to make this work without relying on the concrete implementation of ConstraintViolation (i.e. org.hibernate.validator.internal.engine.ConstraintViolationImpl)?
There doesn't seem to be a reasonable approach to serialize javax.validation.ConstraintViolation objects. In fact, even Jackson errs while trying to serialize the set:
Exception in thread "main" com.fasterxml.jackson.databind.JsonMappingException: fromIndex(0) > toIndex(-1) (through reference chain: java.util.HashSet[0]->org.hibernate.validator.internal.engine.ConstraintViolationImpl["propertyPath"]->org.hibernate.validator.internal.engine.path.PathImpl["pathWithoutLeafNode"]->org.hibernate.validator.internal.engine.path.PathImpl["pathWithoutLeafNode"]->org.hibernate.validator.internal.engine.path.PathImpl["pathWithoutLeafNode"])
at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:232)
For the time being, I just convert the set of errors into a set of custom POJOs I've written and serialize that instead.
Custom ValidationError POJO:
public class ValidationError {
private String className;
private String propertyPath;
private String errorMessage;
public static Set<ValidationError> fromViolations(Set violations) {
Set<ValidationError> errors = new HashSet<ValidationError>();
for (Object o : violations) {
ConstraintViolation v = (ConstraintViolation) o;
ValidationError error = new ValidationError();
error.setClassName(v.getRootBeanClass().getSimpleName());
error.setErrorMessage(v.getMessage());
error.setPropertyPath(v.getPropertyPath().toString());
errors.add(error);
}
return errors;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
public String getPropertyPath() {
return propertyPath;
}
public void setPropertyPath(String propertyPath) {
this.propertyPath = propertyPath;
}
public String getErrorMessage() {
return errorMessage;
}
public void setErrorMessage(String errorMessage) {
this.errorMessage = errorMessage;
}
#Override
public String toString() {
return "ValidationError{" +
"className='" + className + '\'' +
", propertyPath='" + propertyPath + '\'' +
", errorMessage='" + errorMessage + '\'' +
'}';
}
}
Sample usage:
Set<ConstraintViolation<MyBean>> violations = validator.validate(myBean);
Set<ValidationError> errors = ValidationError.fromViolations(violations);
GsonBuilder gsonBuilder = new GsonBuilder();
Gson gson = gsonBuilder.create();
System.out.println(gson.toJson(errors));
Update
For the sake of record, it is worth mentioning that XStream can serialize the set of constraint violations like a charm:
XStream xstream = new XStream(new JettisonMappedXmlDriver());
xstream.setMode(XStream.NO_REFERENCES);
System.out.println(xstream.toXML(violations));
However the generated the object graph is way too much verbose and is not suitable for use in production anyway. You can see the sample output here.