Hi, i need your help in parsing endpoint rest data to an object using restTemplate.getEntity()
As response Json data it has around 70 to 80 fields values , but i am interested in just 5 values , so it is useless to use objectMapper for 80 fields object then extracting 5 values. Is there another easy way to ignore the rest and convert 80 fields json to 5 variables object.
For Example:
"student:{
"name" : "ABC"
"age" : "20"
"address":
{
"place" : "XYZ"
"country" : "Russia"
"state" : "PQR"
}
form these json data i need to convert this to object as
public class Student
{
private String name;
private String country;
\getter and setter
}
please suggest me a better way to convert json to object.
currently I done some wrong way as
String jsonData = restTemplate.getObject(ENDPOINT,String.class)
Student stdObject = new Student();
JSONObject jsonObject = new JSONObject(jsonData);
stdObject.setName(jsonObject.getJSONObject("name"));
Hey folks. I'm trying to serialise a POJO to a JSON array. where the POJO has two properties, but I ant to serialise it into an array with three elements, the 2nd one being a placeholder. Any idea how to do this?
I tried
@JsonFormat(shape = JsonFormat.Shape.ARRAY)
@JsonPropertyOrder()
Pojo {
@JsonProperty(index = 0) String a;
@JsonProperty(index = 2)String b;
}
But that ends up as [a,b] serialised, when I need [a,null,b]
10 replies
Hi, let's say I define a DTO for representing response of one API endpoint. This DTO has around 10 fields and all of these fields are included during deserialization for my first API endpoint.
public class DummyResponseDto1 {
@JsonProperty("id")
private String id;
// ...Now, there is another API endpoint and its response schema is having some fields in common with the previous API endpoint. As I'm aware of DRY principle, I am trying to reuse the previous DTO via composition in the second DTO
public class DummyResponseDto2 {
private DummyResponseDto1 dto;The problem is that: not every field in DummyResponseDto1 will be used in the response of my second API endpoint, so I want to explicitly instruct Jackson ignore those fields. However, since DummyResponseDto1 is also used for my first API endpoint, I cannot simply modify it by adding @JsonIgnore because that would break the contract of my first API endpoint.
I'm seeking for advice on the best "Jackson" way to resolve this problem
6 replies
@JsonProperty to have them included again
import _root_.com.fasterxml.jackson.databind.json.JsonMapper
import _root_.com.fasterxml.jackson.databind.{DeserializationFeature, JsonNode, Module, ObjectMapper, SerializationFeature}
import _root_.com.fasterxml.jackson.module.scala.DefaultScalaModule
import _root_.com.fasterxml.jackson.core.util.DefaultIndenter
import _root_.com.fasterxml.jackson.core.util.DefaultPrettyPrinter
import _root_.com.fasterxml.jackson.core.`type`.TypeReference
import _root_.com.fasterxml.jackson.annotation.JsonSubTypes
import _root_.com.fasterxml.jackson.annotation.JsonSubTypes.Type
import _root_.com.fasterxml.jackson.annotation.JsonTypeInfo
@JsonTypeInfo(
use = JsonTypeInfo.Id.NAME,
include = JsonTypeInfo.As.PROPERTY,
property = "type"
)
@JsonSubTypes(value = Array(
new Type(value = classOf[DatasList], name = "v1:datas")
))
class Result{
val version: String ="2.0"
}
class Datas(node_id:String, address:String)
case class DatasList(var datas: List[Datas]) extends Result
def fromJsonToResult(json: String): Result=
{
val mapper = JsonMapper.builder().addModule(DefaultScalaModule).build()
val ref = new TypeReference[Result] {}
mapper.readValue(json, ref)
}
object Test extends App {
val mapper = JsonMapper.builder().addModule(DefaultScalaModule).build()
val str : String = """ {"datas":[{"id":"0041","address":"12545254"},{"id":"5455a5","address":"44544545"}]} """
println(fromJsonToResult(str))
}
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.sample.Test.main(Test.scala)
Caused by: com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Could not resolve subtype of [simple type, class com.sample.Result]: missing type id property 'type'
at [Source: (String)" {"datas":[{"id":"0041","address":"12545254"},{"id":"5455a5","address":"44544545"}]} "; line: 1, column: 84]Is there a way to configure Mixin class at field level, and do it through annotation, rather than through ObjectMapper setting?
I'm looking for something like
public class JustAnotherDTO {
// is this really possible?
@JsonMixin(FirstDTOMixin.class)
private FirstDTO dtoIn this way, I can control what fields from FirstDTO to be included when FirstDTO is embedded within another DTO class, without directly modifying the source code of FirstDTO.
1 reply
at com.sample.TestJson.main(TestJson.scala)
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type `java.lang.String` from Object value (token `JsonToken.START_OBJECT`)
at [Source: (String)"{"value":"abc","valueSeq":["efg"]}"; line: 1, column: 1]
at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:59)
at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1741)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1515)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1420)
at com.fasterxml.jackson.databind.DeserializationContext.extractScalarFromObject(DeserializationContext.java:932)
at com.fasterxml.jackson.databind.deser.std.StringDeserializer.deserialize(StringDeserializer
AnnotationIntrospector and while overriding the method findAndAddVirtualProperties() I encountered an issue with the names of the fields in the the List<BeanPropertyWriter> properties parameter. For example a field named aProp appears in that list as aprop. It appears that the culprit is com.fasterxml.jackson.databind.introspect.DefaultAccessorNamingStrategy#legacyManglePropertyName(). I would love to make a fix but I'm not exactly sure I'm aware of all the naming conventions to use when transforming getter names in field names. Can anyone advise on this?
2 replies
1 reply
@JsonSerialize annotation for that, but this is a privacy library I'm working on that is meant for others to use across a platform, and the custom annotation is also used for other things like documentation and code generators
1 reply
JsonMapper, is there a way to tell if "default typing" is disabled? I'm trying to write a unit test to ensure some secure defaults, and while some of the other features are easy enough to test with isEnabled, I did not see an obvious approach for checking whether "default typing" is disabled or not.
3 replies
8 replies
5 replies
3 replies
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3 replies
Hi Experts, I was using jersey 1.16 rest server using jackson 2.10.1 and things were fine.
Now I have upgraded jackson to use 2.13.1 and seeing the following error:
Caused by: com.sun.jersey.api.MessageException: A message body writer for Java class java.util.ArrayList, and Java type java.util.List<MYCLASS>, and MIME media type application/json was not found]. Check the service logs also for more information.
at java.lang.Thread.run(Thread.java:748)]. Check the service logs also for more information.
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)]. Check the service logs also for more information.
Do we need to change any configuration to use default JSON object mapper?
Hi guys, We are facing same issue as this. FasterXML/jackson-dataformats-text#190
Is there any solution? The emoji is turning into unicode in the textview on Android, instead of staying as emoji.
2 replies
ObjectMapper-setDateFormat
it states: ObjectMapper itself is only thread-safe when configuring methods (such as this one) are NOT called. Does this just mean it makes the object mapper non-thread-safe if this is called while the application is running/ serving traffic but it is safe to call this method to change the date format while the application is starting up as part of say a spring @Configuration class? Example of what would be done below:
import com.fasterxml.jackson.databind.util.StdDateFormat;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class JacksonConfig {
@Bean
public Jackson2ObjectMapperBuilderCustomizer jacksonObjectMapperBuilder() {
return builder -> builder.dateFormat(new StdDateFormat().withColonInTimeZone(false));
}
}
Hi community,
I just didnt find any other specific room and here looks a general QA room.
I just want to share and understand a case:
I used @JsonManagedReference and @JsonBackReference first on my entities like:
and
and then when I try to add new airport, I got :
But when I try to switch the references, it worked properly. Also, when I add @JsonIgnore annotation any of entity, it also worked properly. From all above, what is the purpose of exact usage of @JsonManagedReference and @JsonBackReference ?
Thanks.
5 replies
Hello everybody,
I was implementing object merging using @JsonMerge and @JsonSetter(nulls= Nulls.SKIP) at field level, and faced with a problem, it doesn't skip nulls in child objects. Maybe someone knows what I'm doing wrong and can help to point me in the right direction.
@NoArgsConstructor
@Setter
@Getter
@AllArgsConstructor
@Builder
@JsonNaming(PropertyNamingStrategy.KebabCaseStrategy.class)
public class Context {
@NotNull
@JsonMerge
@JsonSetter(nulls = Nulls.SKIP)
private FileProperties fileProperties;
@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
@JsonNaming(PropertyNamingStrategy.KebabCaseStrategy.class)
public static class FileProperties {
@NotEmpty
@JsonMerge
@JsonSetter(nulls = Nulls.SKIP)
private String fileName;
@NotNull
@JsonMerge
@JsonSetter(nulls = Nulls.SKIP)
private String folderName;
}
}And test
@SneakyThrows
@Test
public void testNullMerging() {
// GIVEN
var context = Context.builder()
.fileProperties(new Context.FileProperties(
"initialFileName",
"initialFolderName"))
.build();
// AND
var propertiesWithNulls = new HashMap<>();
propertiesWithNulls.put("folder-name", null);
propertiesWithNulls.put("file-name", "updatedFileName");
var toMerge = new HashMap<>();
toMerge.put("file-properties", propertiesWithNulls);
// AND
var mapper = new ObjectMapper();
// WHEN
Context mergedContext = mapper.readerForUpdating(context).readValue(mapper.writeValueAsString(toMerge));
// THEN
assertEquals("updatedFileName", mergedContext.getFileProperties().getFileName());
assertEquals("initialFolderName", mergedContext.getFileProperties().getFolderName());
}I would appreciate any help here
7 replies
Hello! I would understand how Jackson serializes the Boolean wrapper in the following case:
public class Person {
private String Name;
private Boolean employeed;
public Boolean getEmployeed() {
return employeed;
}
public boolean isEmployeed() {
return Boolean.TRUE.equals(employeed);
}
}Which method has higher priority is or get? If jackson uses get it means that the value serialized in JSON can be null, if it uses is this means that the value will be true or false since it returns a primitive. Would be nice attached a doc reference or point me out the code where shows how it works. It looks like this is not example in the java doc documentation. Thanks!
10 replies
Hello, I'm unsure how to solve a problem with Jackson.
capability_types:
tosca.capabilities.Container:
derived_from: tosca.capabilities.Root
interface_types:
node.lifecycle.Standard:
derived_from: Root
operations:
...
relationship_types:
HostedOn:
description:
...
node_types:
TomcatType:
description: Tomcat Webserver
interfaces:
lifecycle:
type: node.lifecycle.Standard
operations:
...
capabilities:
containerCapability: tosca.capabilities.Container
topology_template:
node_templates:
TomcatContainer:
type: TomcatType
TomcatWebApp:
type: WebAppType
requirements:
- host:
node: TomcatContainer
relationship: HostedOnThe yaml file has multiple parts where a value references to a map key. For example the ‘type’ in TomcatWebApp references to node_types -> TomcatType and the ‘node’ value in TomcatWebApp references to the TomcatContainer in the topology_template. Currently I read the referencing values as Strings but I would like them to be references to the Objects. I tried to use @JsonIdentityInfo but for example the TomcatType map entry in node_types does not know its name so how could jackson make the connection?
4 replies
I'm trying to serialize to XML:
Expected:
<SystemName ExportDate="03/27/2022 21:05:22">
<Order-21333 createdOn="03/27/2022 07:05:22">
order content
<Order-21333>
</SystemName>Actual:
<SystemName ExportDate="03/27/2022 21:05:22">
<order>
<Order-21333 createdOn="03/27/2022 07:05:22">
order content
<Order-21333>
</order>
</SystemName>Classes:
@Data
@JacksonXmlRootElement(localName="SystemName")
public class OrderXMLRootDTO {
@JacksonXmlProperty(isAttribute = true, localName="ExportDate")
private String exportDate = DateUtil.formatInstant(Instant.now(), "MM/dd/yyyy HH:mm:ss")
@JsonSerialize(using = OrderSerializer.class)
private OrderXMLDTO order;
}
@Data
public class OrderXMLDTO {
@JsonIgnore
private String orderId;
other fields
}
public class OrderSerializer extends JsonSerializer<OrderXMLDTO> {
@Override
public void serialize(OrderXMLDTO value, JsonGenerator gen, SerializerProvider serializer) throws IOException {
gen.writeStartObject();
gen.writeObjectField("Order-" + value.getOrderId(), value);
}
}As you can see, I cannot get rid of that order wrapper. Can you please help?
4 replies
3 replies
Released to simplify usage by those users who don't use
jackson-bom (and/or don't understand how micropatches work :-( )
Hi everyone, I have a backward-compatible problem with a JSON data, in a Kotlin project, before, we have the following:
data class TranscoderIngressStage(
val id: String,
val provider: String
)That class generates the following JSON:
{
"id": "123",
"provider": "provider1",
}Now, we want to add a new outputs attribute to the class as follows:
data class TranscoderIngressStage(
val id: String,
val provider: String,
var outputs: List<TranscoderOutput>
)
data class TranscoderOutput(
val id: String,
val providerResourceId: String
)If we try to deserialize the previous JSON that doesn't have the outputs property, it fails as the property is required.
Is there any Jackson annotation where I can say: if you don't find the JSON property, set the value as an empty list?
15 replies
Can anyone help explain why
JsonContext.INSTANCE.verifySerializability(new ObjectMapper().readTree("{\"someNumber\": 5}")); fails with a comparison failure?Debugging reveals that
ObjectMapper::readTree() parses the 5 as an IntNode, but inside the call to verifySerializability a call to JsonContext::readValueFromBytes() re-parses the 5 as a LongNode.Why does ObjectMapper and JsonContext produce differently typed numbers?
JsonContext class is from our internal code base, so please disregard my question.