Jackson 3.0.1 · tools.jackson.databind · APIdia, the JavaDoc alternative

Basic data binding (mapping) functionality that allows for reading JSON content into Java Objects (POJOs) and JSON Trees (tools.jackson.databind.JsonNode), as well as writing Java Objects and trees as JSON. Reading and writing (as well as related additional functionality) is accessed through tools.jackson.databind.ObjectMapper, tools.jackson.databind.ObjectReader and tools.jackson.databind.ObjectWriter classes. In addition to reading and writing JSON content, it is also possible to use the general databinding functionality for many other data formats, using Jackson extension modules that provide such support: if so, you typically simply construct an tools.jackson.databind.ObjectMapper with different underlying streaming parser, generator implementation.

The main starting point for operations is tools.jackson.databind.ObjectMapper, which can be used either directly (via multiple overloaded readValue, readTree, writeValue and writeTree methods, or it can be used as a configurable factory for constructing fully immutable, thread-safe and reusable tools.jackson.databind.ObjectReader and tools.jackson.databind.ObjectWriter objects.

In addition to simple reading and writing of JSON as POJOs or JSON trees (represented as tools.jackson.databind.JsonNode, and configurability needed to change aspects of reading/writing, mapper contains additional functionality such as:

Value conversions using tools.jackson.databind.ObjectMapper#convertValue(Object, Class), tools.jackson.databind.ObjectMapper#valueToTree(Object) and tools.jackson.databind.ObjectMapper#treeToValue(tools.jackson.core.TreeNode, Class) methods.
Type introspection needed for things like generation of Schemas (like JSON Schema, Avro Schema, or protoc definitions), using tools.jackson.databind.ObjectMapper#acceptJsonFormatVisitor(Class, tools.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper) (note: actual handles are usually provided by various Jackson modules: mapper simply initiates calling of callbacks, based on serializers registered)

Simplest usage is of form:

  final ObjectMapper mapper = new ObjectMapper(); // can use static singleton, inject: just make sure to reuse!
  MyValue value = new MyValue();
  // ... and configure
  File newState = new File("my-stuff.json");
  mapper.writeValue(newState, value); // writes JSON serialization of MyValue instance
  // or, read
  MyValue older = mapper.readValue(new File("my-older-stuff.json"), MyValue.class);

  // Or if you prefer JSON Tree representation:
  JsonNode root = mapper.readTree(newState);
  // and find values by, for example, using a tools.jackson.core.JsonPointer expression:
  int age = root.at("/personal/age").getValueAsInt();

For more usage, refer to tools.jackson.databind.ObjectMapper, tools.jackson.databind.ObjectReader and tools.jackson.databind.ObjectWriter Javadocs.

Interface Summary

Modifier and Type	Interface and Description
public interface	BeanProperty Bean properties are logical entities that represent data that Java objects (POJOs (Plain Old Java Objects), sometimes also called "beans") contain; and that are accessed using accessors (methods like getters and setters, fields, constructor parameters).
public interface	EnumNamingStrategy Defines how the string representation of an enum is converted into an external property name for mapping during deserialization.
public interface	JacksonSerializable Interface that can be implemented by objects that know how to serialize themselves to JSON, using `JsonGenerator` (and `SerializationContext` if necessary).

Class Summary

Modifier and Type	Class and Description
public abstract class	AbstractTypeResolver Defines interface for resolvers that can resolve abstract types into concrete ones; either by using static mappings, or possibly by materializing implementations dynamically.
public abstract class	AnnotationIntrospector Abstract class that defines API used for introspecting annotation-based configuration for serialization and deserialization.
public abstract class	BeanDescription Basic container for information gathered by `ClassIntrospector` to help in constructing serializers and deserializers.
public abstract class	DatabindContext Shared base class for `DeserializationContext` and `SerializationContext`, context objects passed through data-binding process.
public class	DatabindException Exception used to signal fatal problems with mapping of content, distinct from low-level I/O problems (signaled using simple `JacksonIOException`s) or data encoding/decoding problems (signaled with `tools.jackson.core.exc.StreamReadException`, `tools.jackson.core.exc.StreamWriteException`).
public class	DeserializationConfig Object that contains baseline configuration for deserialization process.
public abstract class	DeserializationContext Context for the process of deserialization a single root-level value.
public class	EnumNamingStrategies A container class for implementations of the `EnumNamingStrategy` interface.
public abstract class	InjectableValues Abstract class that defines API for objects that provide value to "inject" during deserialization.
public abstract class	JacksonModule Simple interface for extensions that can be registered with `ObjectMapper` to provide a well-defined set of extensions to default functionality; such as support for new data types.
public abstract class	JavaType Base class for type token classes used both to contain information and as keys for deserializers.
public abstract class	JsonNode Base class for all JSON nodes, which form the basis of JSON Tree Model that Jackson implements.
public abstract class	KeyDeserializer Abstract class that defines API used for deserializing JSON content field names into Java Map keys.
public class	MappingIterator<T> Iterator exposed by `ObjectMapper` when binding sequence of objects.
public class	ObjectMapper ObjectMapper provides functionality for reading and writing JSON, either to and from basic POJOs (Plain Old Java Objects), or to and from a general-purpose JSON Tree Model (`JsonNode`), as well as related functionality for performing conversions.
public class	ObjectReader Builder object that can be used for per-serialization configuration of deserialization parameters, such as root type to use or object to update (instead of constructing new instance).
public class	ObjectWriter Builder object that can be used for per-serialization configuration of serialization parameters, such as JSON View and root type to use.
public class	PropertyMetadata Simple container class used for storing "additional" metadata about properties.
public class	PropertyName Simple value class used for containing names of properties as defined by annotations (and possibly other configuration sources).
public abstract class	PropertyNamingStrategies Container for standard `PropertyNamingStrategy` implementations and singleton instances.
public class	PropertyNamingStrategy Class that defines how names of JSON properties ("external names") are derived from names of POJO methods and fields ("internal names"), in cases where no explicit annotations exist for naming.
public class	SequenceWriter Writer class similar to `ObjectWriter`, except that it can be used for writing sequences of values, not just a single value.
public class	SerializationConfig Object that contains baseline configuration for serialization process.
public abstract class	SerializationContext Class that defines API used by `ObjectMapper` and `ValueSerializer`s to obtain serializers capable of serializing instances of specific types; as well as the default implementation of the functionality.
public abstract class	ValueDeserializer<T> Abstract class that defines API used by `ObjectMapper` and `ObjectReader` to deserialize Objects of arbitrary types from JSON, using provided `JsonParser` (within current read context of `DeserializationContext`.
public abstract class	ValueSerializer<T> Abstract class that defines API used by `ObjectMapper` (and other chained `ValueSerializer`s too) to serialize Objects of arbitrary types into JSON, using provided `JsonGenerator`.

Enum Summary

Modifier and Type	Enum and Description
public enum	DefaultTyping Enumeration used with `JsonMapper.defaultTyping()` methods to specify what kind of types (classes) default typing should be used for.
public enum	DeserializationFeature Enumeration that defines simple on/off features that affect the way Java objects are deserialized from JSON Note that features can be set both through `ObjectMapper` (as sort of defaults) and through `ObjectReader`.
public enum	MapperFeature Enumeration that defines simple on/off features to set for `ObjectMapper`, and accessible (but not changeable) via `ObjectReader` and `ObjectWriter` (as well as through various convenience methods through context objects).
public enum	SerializationFeature Enumeration that defines simple on/off features that affect the way Java objects are serialized.

Package tools.jackson.databind

Interface Summary

Class Summary

Enum Summary