Jackson Essentials

Defining profiles for dynamic ignore: @JsonView
Using Jackson JSON View to Protect Mass Assignment Vulnerabilities

@JsonView(Views.Public.class)
@JsonView(Views.Internal.class)

Annotations

@JsonInclude(Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonIgnoreProperties({"propertyA", "propertyB"})
@JsonIgnoreType

@JsonProperty("anotherName") - give a different name

@JsonIgnore

Custom JSON Deserialization and Serialization 
@JsonDeserialize, @JsonSerialize
JsonDeserializer, JsonSerializer 

@JsonAutoDetect(fieldVisibility = Visibility.ANY, getterVisibility = Visibility.NONE, setterVisibility = Visibility.NONE) 

@JsonUnwrapped
@JsonUnwrapped public Location location; 

Polymorphic Types

@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME,
    include = JsonTypeInfo.As.PROPERTY,
    property = "type")
@JsonSubTypes({
    @Type(value = A.class, name = "a"),
    @Type(value = B.class, name = "b") })

@JsonTypeName(SubType1.TYPE)

Customize objectMapper

Jackson Date Serialize + Deserialize
We can configure all sub classes of ConfigFeature: MapperFeature, DeserializationFeature, SerializationFeature, JaxRSFeature.

new ObjectMapper()
        .registerModule(new JavaTimeModule())
        .setDateFormat(new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss"))
        .configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true)
        .configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true)
        .configure(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS, true)
        .configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, false)
        .configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false)
        .configure(DeserializationFeature.FAIL_ON_NUMBERS_FOR_ENUMS, false)
        .configure(DeserializationFeature.FAIL_ON_READING_DUP_TREE_KEY, false)
        .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
        .configure(DeserializationFeature.FAIL_ON_UNRESOLVED_OBJECT_IDS, false)
        .setSerializationInclusion(Include.NON_NULL)
        .configure(SerializationFeature.INDENT_OUTPUT, true);

Using Java8 Types
Use jackson-datatype-jdk8 and jackson-datatype-jsr310 readValue
JavaType - preferred
- Use TypeFactory

JavaType javaType = mapper.getTypeFactory().constructCollectionType(List.class, SomeType.class);
TypeFactory.defaultInstance().constructType(SomeType.class);
TypeFactory.defaultInstance().constructMapType(Map.class, String.class, SomeType.class);

objectMapper.readValue(json, JavaType)

SomeType[] array = mapper.readValue(jsonArray, SomeType[].class);

TypeReference
Convert json to Map<String, SomeType>

mapper.readValue(json, new TypeReference<Map<String, SomeType>>(){});

Jersey -Customize Jackson objectmapper

@Provider
public class JerseyObjectMapperProvider implements ContextResolver<ObjectMapper> {
    private static ObjectMapper objectMapper = Util.createFailSafeObjectmapper();
    @Override
    public ObjectMapper getContext(final Class<?> type) {
        return objectMapper;
    }
}

@JsonCreator + @JsonValue

public enum XEnum {
  A("value1"), B("value2");
  private final String value;
  XEnum(final String value) {
   this.value = value;
  } 
  @JsonValue
  String getValue() { return value;}
  public static XEnum fromString(final String value) {
   return getEnumfromString(value, XEnum)
  }
}

public static <E extends Enum<E>> E getEnumfromString(final String value, final Class<E> enumType) {
  return Enum.valueOf(enumType, value.toUpperCase());
}

To use scala case class with Jackson: add @BeanProperty to the field.

Read More
Jackson Essentials - the JSON Libaray
Using Jackson JSON View to Protect Mass Assignment Vulnerabilities
Merge JSON Objects: Jackson + BeanUtils.copyProperties
Jackson Generic Type + Java Type Erasure
Jackson Date Serialize + Deserialize