org.codehaus.jackson.jaxrs
Class JacksonJsonProvider

java.lang.Object
  extended by org.codehaus.jackson.jaxrs.JacksonJsonProvider
All Implemented Interfaces:
MessageBodyReader<Object>, MessageBodyWriter<Object>
Direct Known Subclasses:
JacksonJaxbJsonProvider

@Provider
public class JacksonJsonProvider
extends Object
implements MessageBodyReader<Object>, MessageBodyWriter<Object>

Basic implementation of JAX-RS abstractions (MessageBodyReader, MessageBodyWriter) needed for binding JSON ("application/json") content to and from Java Objects ("POJO"s).

Actual data binding functionality is implemented by ObjectMapper: mapper to use can be configured in multiple ways:

The last method ("do nothing specific") is often good enough; explicit passing of Mapper is simple and explicit; and Provider-based method may make sense with Depedency Injection frameworks, or if Mapper has to be configured differently for different media types.

Note that the default mapper instance will be automatically created if one of explicit configuration methods (like configure(org.codehaus.jackson.map.DeserializationConfig.Feature, boolean)) is called: if so, Provider-based introspection is NOT used, but the resulting Mapper is used as configured.

Note: version 1.3 added a sub-class (JacksonJaxbJsonProvider) which is configured by default to use both Jackson and JAXB annotations for configuration (base class when used as-is defaults to using just Jackson annotations)

Author:
Tatu Saloranta

Field Summary
protected  boolean _cfgCheckCanDeserialize
          Whether we want to actually check that Jackson has a deserializer for given type.
protected  boolean _cfgCheckCanSerialize
          Whether we want to actually check that Jackson has a serializer for given type.
protected  HashSet<ClassKey> _cfgCustomUntouchables
          Set of types (classes) that provider should ignore for data binding
protected  String _jsonpFunctionName
          JSONP function name to use for automatic JSONP wrapping, if any; if null, no JSONP wrapping is done.
protected  MapperConfigurator _mapperConfig
          Helper object used for encapsulating configuration aspects of ObjectMapper
protected  Providers _providers
          Injectable context object used to locate configured instance of ObjectMapper to use for actual serialization.
static Class<?>[] _unreadableClasses
          These are classes that we never use for reading (never try to deserialize instances of these types).
static HashSet<ClassKey> _untouchables
          Looks like we need to worry about accidental data binding for types we shouldn't be handling.
static Class<?>[] _unwritableClasses
          These are classes that we never use for writing (never try to serialize instances of these types).
static Annotations[] BASIC_ANNOTATIONS
          Default annotation sets to use, if not explicitly defined during construction: only Jackson annotations are used for the base class.
 
Constructor Summary
JacksonJsonProvider()
          Default constructor, usually used when provider is automatically configured to be used with JAX-RS implementation.
JacksonJsonProvider(Annotations... annotationsToUse)
           
JacksonJsonProvider(ObjectMapper mapper)
           
JacksonJsonProvider(ObjectMapper mapper, Annotations[] annotationsToUse)
          Constructor to use when a custom mapper (usually components like serializer/deserializer factories that have been configured) is to be used.
 
Method Summary
protected static boolean _containedIn(Class<?> mainType, HashSet<ClassKey> set)
           
protected  JavaType _convertType(Type jdkType)
          Method used to construct a JDK generic type into type definition Jackson understands.
 void addUntouchable(Class<?> type)
          Method for marking specified type as "untouchable", meaning that provider will not try to read or write values of this type (or its subtypes).
 void checkCanDeserialize(boolean state)
          Method for defining whether actual detection for existence of a deserializer for type should be done when isReadable(java.lang.Class, java.lang.reflect.Type, java.lang.annotation.Annotation[], javax.ws.rs.core.MediaType) is called.
 void checkCanSerialize(boolean state)
          Method for defining whether actual detection for existence of a serializer for type should be done when isWriteable(java.lang.Class, java.lang.reflect.Type, java.lang.annotation.Annotation[], javax.ws.rs.core.MediaType) is called.
 JacksonJsonProvider configure(DeserializationConfig.Feature f, boolean state)
           
 JacksonJsonProvider configure(JsonGenerator.Feature f, boolean state)
           
 JacksonJsonProvider configure(JsonParser.Feature f, boolean state)
           
 JacksonJsonProvider configure(SerializationConfig.Feature f, boolean state)
           
 JacksonJsonProvider disable(DeserializationConfig.Feature f, boolean state)
           
 JacksonJsonProvider disable(JsonGenerator.Feature f, boolean state)
           
 JacksonJsonProvider disable(JsonParser.Feature f, boolean state)
           
 JacksonJsonProvider disable(SerializationConfig.Feature f, boolean state)
           
 JacksonJsonProvider enable(DeserializationConfig.Feature f, boolean state)
           
 JacksonJsonProvider enable(JsonGenerator.Feature f, boolean state)
           
 JacksonJsonProvider enable(JsonParser.Feature f, boolean state)
           
 JacksonJsonProvider enable(SerializationConfig.Feature f, boolean state)
           
 long getSize(Object value, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)
          Method that JAX-RS container calls to try to figure out serialized length of given value.
protected  boolean isJsonType(MediaType mediaType)
          Helper method used to check whether given media type is JSON type or sub type.
 boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)
          Method that JAX-RS container calls to try to check whether values of given type (and media type) can be deserialized by this provider.
 boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)
          Method that JAX-RS container calls to try to check whether given value (of specified type) can be serialized by this provider.
 ObjectMapper locateMapper(Class<?> type, MediaType mediaType)
          Method called to locate ObjectMapper to use for serialization and deserialization.
 Object readFrom(Class<Object> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String,String> httpHeaders, InputStream entityStream)
          Method that JAX-RS container calls to deserialize given value.
 void setAnnotationsToUse(Annotations[] annotationsToUse)
          Method for configuring which annotation sets to use (including none).
 void setJSONPFunctionName(String fname)
           
 void setMapper(ObjectMapper m)
          Method that can be used to directly define ObjectMapper to use for serialization and deserialization; if null, will use the standard provider discovery from context instead.
 void writeTo(Object value, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String,Object> httpHeaders, OutputStream entityStream)
          Method that JAX-RS container calls to serialize given value.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

BASIC_ANNOTATIONS

public static final Annotations[] BASIC_ANNOTATIONS
Default annotation sets to use, if not explicitly defined during construction: only Jackson annotations are used for the base class. Sub-classes can use other settings.


_untouchables

public static final HashSet<ClassKey> _untouchables
Looks like we need to worry about accidental data binding for types we shouldn't be handling. This is probably not a very good way to do it, but let's start by blacklisting things we are not to handle.

(why ClassKey? since plain old Class has no hashCode() defined, lookups are painfully slow)


_unreadableClasses

public static final Class<?>[] _unreadableClasses
These are classes that we never use for reading (never try to deserialize instances of these types).


_unwritableClasses

public static final Class<?>[] _unwritableClasses
These are classes that we never use for writing (never try to serialize instances of these types).


_mapperConfig

protected final MapperConfigurator _mapperConfig
Helper object used for encapsulating configuration aspects of ObjectMapper


_cfgCustomUntouchables

protected HashSet<ClassKey> _cfgCustomUntouchables
Set of types (classes) that provider should ignore for data binding

Since:
1.5

_jsonpFunctionName

protected String _jsonpFunctionName
JSONP function name to use for automatic JSONP wrapping, if any; if null, no JSONP wrapping is done.


_providers

@Context
protected Providers _providers
Injectable context object used to locate configured instance of ObjectMapper to use for actual serialization.


_cfgCheckCanSerialize

protected boolean _cfgCheckCanSerialize
Whether we want to actually check that Jackson has a serializer for given type. Since this should generally be the case (due to auto-discovery) and since the call to check availability can be bit expensive, defaults to false.


_cfgCheckCanDeserialize

protected boolean _cfgCheckCanDeserialize
Whether we want to actually check that Jackson has a deserializer for given type. Since this should generally be the case (due to auto-discovery) and since the call to check availability can be bit expensive, defaults to false.

Constructor Detail

JacksonJsonProvider

public JacksonJsonProvider()
Default constructor, usually used when provider is automatically configured to be used with JAX-RS implementation.


JacksonJsonProvider

public JacksonJsonProvider(Annotations... annotationsToUse)
Parameters:
annotationsToUse - Annotation set(s) to use for configuring data binding

JacksonJsonProvider

public JacksonJsonProvider(ObjectMapper mapper)

JacksonJsonProvider

public JacksonJsonProvider(ObjectMapper mapper,
                           Annotations[] annotationsToUse)
Constructor to use when a custom mapper (usually components like serializer/deserializer factories that have been configured) is to be used.

Method Detail

checkCanDeserialize

public void checkCanDeserialize(boolean state)
Method for defining whether actual detection for existence of a deserializer for type should be done when isReadable(java.lang.Class, java.lang.reflect.Type, java.lang.annotation.Annotation[], javax.ws.rs.core.MediaType) is called.


checkCanSerialize

public void checkCanSerialize(boolean state)
Method for defining whether actual detection for existence of a serializer for type should be done when isWriteable(java.lang.Class, java.lang.reflect.Type, java.lang.annotation.Annotation[], javax.ws.rs.core.MediaType) is called.


setAnnotationsToUse

public void setAnnotationsToUse(Annotations[] annotationsToUse)
Method for configuring which annotation sets to use (including none). Annotation sets are defined in order decreasing precedence; that is, first one has the priority over following ones.

Parameters:
annotationsToUse - Ordered list of annotation sets to use; if null, default

setMapper

public void setMapper(ObjectMapper m)
Method that can be used to directly define ObjectMapper to use for serialization and deserialization; if null, will use the standard provider discovery from context instead. Default setting is null.


configure

public JacksonJsonProvider configure(DeserializationConfig.Feature f,
                                     boolean state)

configure

public JacksonJsonProvider configure(SerializationConfig.Feature f,
                                     boolean state)

configure

public JacksonJsonProvider configure(JsonParser.Feature f,
                                     boolean state)

configure

public JacksonJsonProvider configure(JsonGenerator.Feature f,
                                     boolean state)

enable

public JacksonJsonProvider enable(DeserializationConfig.Feature f,
                                  boolean state)

enable

public JacksonJsonProvider enable(SerializationConfig.Feature f,
                                  boolean state)

enable

public JacksonJsonProvider enable(JsonParser.Feature f,
                                  boolean state)

enable

public JacksonJsonProvider enable(JsonGenerator.Feature f,
                                  boolean state)

disable

public JacksonJsonProvider disable(DeserializationConfig.Feature f,
                                   boolean state)

disable

public JacksonJsonProvider disable(SerializationConfig.Feature f,
                                   boolean state)

disable

public JacksonJsonProvider disable(JsonParser.Feature f,
                                   boolean state)

disable

public JacksonJsonProvider disable(JsonGenerator.Feature f,
                                   boolean state)

addUntouchable

public void addUntouchable(Class<?> type)
Method for marking specified type as "untouchable", meaning that provider will not try to read or write values of this type (or its subtypes).

Parameters:
type - Type to consider untouchable; can be any kind of class, including abstract class or interface. No instance of this type (including subtypes, i.e. types assignable to this type) will be read or written by provider
Since:
1.5

setJSONPFunctionName

public void setJSONPFunctionName(String fname)

isReadable

public boolean isReadable(Class<?> type,
                          Type genericType,
                          Annotation[] annotations,
                          MediaType mediaType)
Method that JAX-RS container calls to try to check whether values of given type (and media type) can be deserialized by this provider. Implementation will first check that expected media type is a JSON type (via call to isJsonType(javax.ws.rs.core.MediaType); then verify that type is not one of "untouchable" types (types we will never automatically handle), and finally that there is a deserializer for type (iff checkCanDeserialize(boolean) has been called with true argument -- otherwise assumption is there will be a handler)

Specified by:
isReadable in interface MessageBodyReader<Object>

readFrom

public Object readFrom(Class<Object> type,
                       Type genericType,
                       Annotation[] annotations,
                       MediaType mediaType,
                       MultivaluedMap<String,String> httpHeaders,
                       InputStream entityStream)
                throws IOException
Method that JAX-RS container calls to deserialize given value.

Specified by:
readFrom in interface MessageBodyReader<Object>
Throws:
IOException

getSize

public long getSize(Object value,
                    Class<?> type,
                    Type genericType,
                    Annotation[] annotations,
                    MediaType mediaType)
Method that JAX-RS container calls to try to figure out serialized length of given value. Since computation of this length is about as expensive as serialization itself, implementation will return -1 to denote "not known", so that container will determine length from actual serialized output (if needed).

Specified by:
getSize in interface MessageBodyWriter<Object>

isWriteable

public boolean isWriteable(Class<?> type,
                           Type genericType,
                           Annotation[] annotations,
                           MediaType mediaType)
Method that JAX-RS container calls to try to check whether given value (of specified type) can be serialized by this provider. Implementation will first check that expected media type is a JSON type (via call to isJsonType(javax.ws.rs.core.MediaType); then verify that type is not one of "untouchable" types (types we will never automatically handle), and finally that there is a serializer for type (iff checkCanSerialize(boolean) has been called with true argument -- otherwise assumption is there will be a handler)

Specified by:
isWriteable in interface MessageBodyWriter<Object>

writeTo

public void writeTo(Object value,
                    Class<?> type,
                    Type genericType,
                    Annotation[] annotations,
                    MediaType mediaType,
                    MultivaluedMap<String,Object> httpHeaders,
                    OutputStream entityStream)
             throws IOException
Method that JAX-RS container calls to serialize given value.

Specified by:
writeTo in interface MessageBodyWriter<Object>
Throws:
IOException

isJsonType

protected boolean isJsonType(MediaType mediaType)
Helper method used to check whether given media type is JSON type or sub type. Current implementation essentially checks to see whether MediaType.getSubtype() returns "json" or something ending with "+json".


locateMapper

public ObjectMapper locateMapper(Class<?> type,
                                 MediaType mediaType)
Method called to locate ObjectMapper to use for serialization and deserialization. If an instance has been explicitly defined by setMapper(org.codehaus.jackson.map.ObjectMapper) (or non-null instance passed in constructor), that will be used. If not, will try to locate it using standard JAX-RS ContextResolver mechanism, if it has been properly configured to access it (by JAX-RS runtime). Finally, if no mapper is found, will return a default unconfigured ObjectMapper instance (one constructed with default constructor and not modified in any way)

Parameters:
type - Class of object being serialized or deserialized; not checked at this point, since it is assumed that unprocessable classes have been already weeded out, but will be passed to ContextResolver as is.
mediaType - Declared media type for the instance to process: not used by this method, but will be passed to ContextResolver as is.

_convertType

protected JavaType _convertType(Type jdkType)
Method used to construct a JDK generic type into type definition Jackson understands.


_containedIn

protected static boolean _containedIn(Class<?> mainType,
                                      HashSet<ClassKey> set)