You can use @JsonInclude(JsonInclude.Include.NON_EMPTY) annotation on your class or filed. import com.fasterxml.jackson.annotation.JsonInclude; @JsonInclude(JsonInclude.Include.NON_EMPTY) class Person { String name; List<Event> events; //….getter, setter }
You can do this to traverse the tree and keep track of how deep you are to figure out dot notation property names: import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ArrayNode; import com.fasterxml.jackson.databind.node.ObjectNode; import com.fasterxml.jackson.databind.node.ValueNode; import java.io.IOException; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import org.junit.Test; public class FlattenJson { String json = “{\n” + ” \”Port\”:\n” + … Read more
Jackson processes @JsonTypeInfo before choosing which Deserializer to use, probably because the choice of Deserializer could depend generally on the type. However, you can easily disable this on a per-field basis the same way you specify custom Deserializer – by annotating the field directly: @JsonDeserialize(using = DefinitionDeserializer.class) @JsonTypeInfo(use = JsonTypeInfo.Id.NONE) private Definition definition;
You need a constructor with all parameters: public SampleRequest(String fromDate, String toDate) { this.fromDate = fromDate; this.toDate = toDate; } Or using @AllArgsConstructor or @Data from lombok.
The various reasons for why this happens are discussed here and here. I don’t necessarily agree with the reasons, but Jackson, because of type erasure, doesn’t off the bat know the type of elements the List (or Collection or Map) contains. It chooses to use a simple serializer that doesn’t interpret your annotations. You have … Read more
This exception is raised because you’re trying to deserialize a List in a Map. The solution is create a TypeReference of List<Map<String, Object>>: List<Map<String, Object>> myObjects = mapper.readValue(mapData , new TypeReference<List<Map<String, Object>>>(){});
Solution is SpringBeanAutowiringSupport if you are using Spring Framework 2.5+. public class DesignSerializer extends JsonSerializer<Design> { @Autowired IDesignService designService; } public DesignSerializer(){ SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); } … } I Hope that help you
If you don’t want to extend DefaultPrettyPrinter you can also just set the indentArraysWith property externally: ObjectMapper objectMapper = new ObjectMapper(); objectMapper.enable(SerializationFeature.INDENT_OUTPUT); DefaultPrettyPrinter prettyPrinter = new DefaultPrettyPrinter(); prettyPrinter.indentArraysWith(DefaultIndenter.SYSTEM_LINEFEED_INSTANCE); String json = objectMapper.writer(prettyPrinter).writeValueAsString(object);
When I had this problem I had the jackson-annotations and jackson-databind jars in my classpath, but not jackson-core. Adding jackson-core to the classpath solved it for me.
Short answer: @JsonIgnoreProperties(ignoreUnknown=true) is applicable at deserialization of JSON to Java object (POJO) only. If your POJO does not contain certain properties that JSON does contain, they are ignored and no error is thrown. On the other hand @JsonInclude(Include.NON_EMPTY) is used at serialization of POJO to JSON and it says, skip POJO properties that are: … Read more