EE4J Core API 10.0.0 · jakarta.ws.rs.ext.MessageBodyWriter

Contract for a provider that supports the conversion of a Java type to a stream. A MessageBodyWriter implementation may be annotated with jakarta.ws.rs.Produces to restrict the media types for which it will be considered suitable. The MessageBodyWriter pipeline is only invoked if there is a non-null response entity.

Providers implementing MessageBodyWriter contract must be either programmatically registered in a JAX-RS runtime or must be annotated with @Provider annotation to be automatically discovered by the JAX-RS runtime during a provider scanning phase.

Method Summary

Modifier and Type	Method and Description
public default long	Returns: length in bytes or -1 if the length cannot be determined in advance. getSize(final T the instance to write t, final Class<?> the class of instance that is to be written. type, final Type the type of instance to be written. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. genericType, final Annotation[] an array of the annotations attached to the message entity instance. annotations, final MediaType the media type of the HTTP entity. mediaType) Originally, the method has been called before `writeTo` to ascertain the length in bytes of the serialized form of `t`.
public boolean	Returns: `true` if the type is supported, otherwise `false`. isWriteable(Class<?> the class of instance that is to be written. type, Type the type of instance to be written, obtained either by reflection of a resource method return type or via inspection of the returned instance. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. genericType, Annotation[] an array of the annotations attached to the message entity instance. annotations, MediaType the media type of the HTTP entity. mediaType) Ascertain if the MessageBodyWriter supports a particular type.
public void	writeTo(T the instance to write. t, Class<?> the class of instance that is to be written. type, Type the type of instance to be written. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. genericType, Annotation[] an array of the annotations attached to the message entity instance. annotations, MediaType the media type of the HTTP entity. mediaType, MultivaluedMap<String, Object> a mutable map of the HTTP message headers. httpHeaders, OutputStream the `OutputStream` for the HTTP entity. The implementation must not close the output stream. entityStream) Write a type to an HTTP message.

Method Detail

getSize back to summary

getSize	back to summary
public default long getSize(final T t, final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) Originally, the method has been called before `writeTo` to ascertain the length in bytes of the serialized form of `t`. A non-negative return value has been used in a HTTP `Content-Length` header. As of JAX-RS 2.0, the method has been deprecated and the value returned by the method is ignored by a JAX-RS runtime. All `MessageBodyWriter` implementations are advised to return `-1` from the method. Responsibility to compute the actual `Content-Length` header value has been delegated to JAX-RS runtime. Parameters t:T the instance to write type:Class<?> the class of instance that is to be written. genericType:Type the type of instance to be written. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. annotations:Annotation[] an array of the annotations attached to the message entity instance. mediaType:MediaType the media type of the HTTP entity. Returns:long length in bytes or -1 if the length cannot be determined in advance.

public default long getSize(final T t, final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType)

Originally, the method has been called before writeTo to ascertain the length in bytes of the serialized form of t. A non-negative return value has been used in a HTTP Content-Length header.

As of JAX-RS 2.0, the method has been deprecated and the value returned by the method is ignored by a JAX-RS runtime. All MessageBodyWriter implementations are advised to return -1 from the method. Responsibility to compute the actual Content-Length header value has been delegated to JAX-RS runtime.

Parameters

t:T: the instance to write
type:Class<?>: the class of instance that is to be written.
genericType:Type: the type of instance to be written. jakarta.ws.rs.core.GenericEntity provides a way to specify this information at runtime.
annotations:Annotation[]: an array of the annotations attached to the message entity instance.
mediaType:MediaType: the media type of the HTTP entity.

Returns:long

length in bytes or -1 if the length cannot be determined in advance.

isWriteable back to summary

isWriteable	back to summary
public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) Ascertain if the MessageBodyWriter supports a particular type. Parameters type:Class<?> the class of instance that is to be written. genericType:Type the type of instance to be written, obtained either by reflection of a resource method return type or via inspection of the returned instance. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. annotations:Annotation[] an array of the annotations attached to the message entity instance. mediaType:MediaType the media type of the HTTP entity. Returns:boolean `true` if the type is supported, otherwise `false`.

public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)

Ascertain if the MessageBodyWriter supports a particular type.

Parameters

type:Class<?>: the class of instance that is to be written.
genericType:Type: the type of instance to be written, obtained either by reflection of a resource method return type or via inspection of the returned instance. jakarta.ws.rs.core.GenericEntity provides a way to specify this information at runtime.
annotations:Annotation[]: an array of the annotations attached to the message entity instance.
mediaType:MediaType: the media type of the HTTP entity.

Returns:boolean

true if the type is supported, otherwise false.

writeTo back to summary

writeTo	back to summary
public void writeTo(T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException Write a type to an HTTP message. The message header map is mutable but any changes must be made before writing to the output stream since the headers will be flushed prior to writing the message body. Parameters t:T the instance to write. type:Class<?> the class of instance that is to be written. genericType:Type the type of instance to be written. `jakarta.ws.rs.core.GenericEntity` provides a way to specify this information at runtime. annotations:Annotation[] an array of the annotations attached to the message entity instance. mediaType:MediaType the media type of the HTTP entity. httpHeaders:MultivaluedMap<String, Object> a mutable map of the HTTP message headers. entityStream:OutputStream the `OutputStream` for the HTTP entity. The implementation must not close the output stream. Exceptions IOException: if an IO error arises. WebApplicationException: if a specific HTTP error response needs to be produced. Only effective if thrown prior to the message being committed.

public void writeTo(T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException

Write a type to an HTTP message. The message header map is mutable but any changes must be made before writing to the output stream since the headers will be flushed prior to writing the message body.

Parameters

t:T: the instance to write.
type:Class<?>: the class of instance that is to be written.
genericType:Type: the type of instance to be written. jakarta.ws.rs.core.GenericEntity provides a way to specify this information at runtime.
annotations:Annotation[]: an array of the annotations attached to the message entity instance.
mediaType:MediaType: the media type of the HTTP entity.
httpHeaders:MultivaluedMap<String, Object>: a mutable map of the HTTP message headers.
entityStream:OutputStream: the OutputStream for the HTTP entity. The implementation must not close the output stream.

Exceptions

IOException:: if an IO error arises.
WebApplicationException:: if a specific HTTP error response needs to be produced. Only effective if thrown prior to the message being committed.

public Interface MessageBodyWriter<T>

Method Summary

Method Detail