T
- Java type supported by the providerpublic interface MessageBodyReader<T>
MessageBodyReader
implementation may be annotated with Consumes
to restrict the media
types for which it will be considered suitable. The MessageBodyReader
pipeline is executed if the matching
resource method declares an entity parameter or uses at least one FormParam
.
Providers implementing MessageBodyReader
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.
Modifier and Type | Method and Description |
---|---|
boolean |
isReadable(java.lang.Class<?> type,
java.lang.reflect.Type genericType,
java.lang.annotation.Annotation[] annotations,
MediaType mediaType)
Ascertain if the MessageBodyReader can produce an instance of a particular type.
|
T |
readFrom(java.lang.Class<T> type,
java.lang.reflect.Type genericType,
java.lang.annotation.Annotation[] annotations,
MediaType mediaType,
MultivaluedMap<java.lang.String,java.lang.String> httpHeaders,
java.io.InputStream entityStream)
Read a type from the
InputStream . |
boolean isReadable(java.lang.Class<?> type, java.lang.reflect.Type genericType, java.lang.annotation.Annotation[] annotations, MediaType mediaType)
type
parameter gives the
class of the instance that should be produced, the genericType
parameter gives the
java.lang.reflect.Type
of the instance that should be produced. E.g. if the instance
to be produced is List<String>
, the type
parameter will be java.util.List
and the
genericType
parameter will be java.lang.reflect.ParameterizedType
.type
- the class of instance to be produced.genericType
- the type of instance to be produced. E.g. if the message body is to be converted into a method
parameter, this will be the formal type of the method parameter as returned by
Method.getGenericParameterTypes
.annotations
- an array of the annotations on the declaration of the artifact that will be initialized with the
produced instance. E.g. if the message body is to be converted into a method parameter, this will be the annotations
on that parameter returned by Method.getParameterAnnotations
.mediaType
- the media type of the HTTP entity, if one is not specified in the request then
application/octet-stream
is used.true
if the type is supported, otherwise false
.T readFrom(java.lang.Class<T> type, java.lang.reflect.Type genericType, java.lang.annotation.Annotation[] annotations, MediaType mediaType, MultivaluedMap<java.lang.String,java.lang.String> httpHeaders, java.io.InputStream entityStream) throws java.io.IOException, WebApplicationException
InputStream
.
In case the entity input stream is empty, the reader is expected to either return a Java representation of a
zero-length entity or throw a NoContentException
in case no zero-length entity
representation is defined for the supported Java type. A NoContentException
, if thrown by a message body
reader while reading a server request entity, is automatically translated by JAX-RS server runtime into a
BadRequestException
wrapping the original NoContentException
and rethrown for a standard
processing by the registered exception mappers
.
type
- the type that is to be read from the entity stream.genericType
- the type of instance to be produced. E.g. if the message body is to be converted into a method
parameter, this will be the formal type of the method parameter as returned by
Method.getGenericParameterTypes
.annotations
- an array of the annotations on the declaration of the artifact that will be initialized with the
produced instance. E.g. if the message body is to be converted into a method parameter, this will be the annotations
on that parameter returned by Method.getParameterAnnotations
.mediaType
- the media type of the HTTP entity.httpHeaders
- the read-only HTTP headers associated with HTTP entity.entityStream
- the InputStream
of the HTTP entity. The caller is responsible for ensuring that the input
stream ends when the entity has been consumed. The implementation should not close the input stream.NoContentException
in
case no zero-length entity representation is defined for the supported Java type.java.io.IOException
- if an IO error arises. In case the entity input stream is empty and the reader is not
able to produce a Java representation for a zero-length entity, NoContentException
is expected to be thrown.WebApplicationException
- if a specific HTTP error response needs to be produced. Only effective if
thrown prior to the response being committed.