Class AbstractHttpMessageConverter<T>

Field Detail

• logger

  protected final Log logger

  Logger available to subclasses

Constructor Detail

• AbstractHttpMessageConverter

  protected AbstractHttpMessageConverter()

  Construct an AbstractHttpMessageConverter with no supported media types.

  See Also:

  setSupportedMediaTypes(java.util.List<org.springframework.http.MediaType>)

• AbstractHttpMessageConverter

  protected AbstractHttpMessageConverter​(MediaType supportedMediaType)

  Construct an AbstractHttpMessageConverter with one supported media type.

  Parameters:

  supportedMediaType - the supported media type

• AbstractHttpMessageConverter

  protected AbstractHttpMessageConverter​(MediaType... supportedMediaTypes)

  Construct an AbstractHttpMessageConverter with multiple supported media types.

  Parameters:

  supportedMediaTypes - the supported media types

• AbstractHttpMessageConverter

  protected AbstractHttpMessageConverter​(Charset defaultCharset,
                                         MediaType... supportedMediaTypes)

  Construct an AbstractHttpMessageConverter with a default charset and multiple supported media types.

  Parameters:

  defaultCharset - the default character set

  supportedMediaTypes - the supported media types

  Since:

  4.3

Method Detail

• setSupportedMediaTypes

  public void setSupportedMediaTypes​(List<MediaType> supportedMediaTypes)

  Set the list of MediaType objects supported by this converter.

• getSupportedMediaTypes

  public List<MediaType> getSupportedMediaTypes()

  Description copied from interface: HttpMessageConverter
  Return the list of MediaType objects supported by this converter.

  Specified by:

  getSupportedMediaTypes in interface HttpMessageConverter<T>

  Returns:

  the list of supported media types, potentially an immutable copy

• setDefaultCharset

  public void setDefaultCharset​(Charset defaultCharset)

  Set the default character set, if any.

  Since:

  4.3

• getDefaultCharset

  public Charset getDefaultCharset()

  Return the default character set, if any.

  Since:

  4.3

• canRead

  public boolean canRead​(Class<?> clazz,
                         MediaType mediaType)

  This implementation checks if the given class is supported, and if the supported media typesinclude the given media type.

  Specified by:

  canRead in interface HttpMessageConverter<T>

  Parameters:

  clazz - the class to test for readability

  mediaType - the media type to read (can be null if not specified); typically the value of a Content-Type header.

  Returns:

  true if readable; false otherwise

• canRead

  protected boolean canRead​(MediaType mediaType)

  Returns true if any of the supported media types include the given media type.

  Parameters:

  mediaType - the media type to read, can be null if not specified. Typically the value of a Content-Type header.

  Returns:

  true if the supported media types include the media type, or if the media type is null

• canWrite

  public boolean canWrite​(Class<?> clazz,
                          MediaType mediaType)

  This implementation checks if the given class is supported, and if the supported media types include the given media type.

  Specified by:

  canWrite in interface HttpMessageConverter<T>

  Parameters:

  clazz - the class to test for writability

  mediaType - the media type to write (can be null if not specified); typically the value of an Accept header.

  Returns:

  true if writable; false otherwise

• canWrite

  protected boolean canWrite​(MediaType mediaType)

  Returns true if the given media type includes any of the supported media types.

  Parameters:

  mediaType - the media type to write, can be null if not specified. Typically the value of an Accept header.

  Returns:

  true if the supported media types are compatible with the media type, or if the media type is null

• read

  public final T read​(Class<? extends T> clazz,
                      HttpInputMessage inputMessage)
               throws IOException,
                      HttpMessageNotReadableException

  This implementation simple delegates to readInternal(Class, HttpInputMessage). Future implementations might add some default behavior, however.

  Specified by:

  read in interface HttpMessageConverter<T>

  Parameters:

  clazz - the type of object to return. This type must have previously been passed to the canRead method of this interface, which must have returned true.

  inputMessage - the HTTP input message to read from

  Returns:

  the converted object

  Throws:

  IOException - in case of I/O errors

  HttpMessageNotReadableException - in case of conversion errors

• write

  public final void write​(T t,
                          MediaType contentType,
                          HttpOutputMessage outputMessage)
                   throws IOException,
                          HttpMessageNotWritableException

  This implementation sets the default headers by calling addDefaultHeaders(org.springframework.http.HttpHeaders, T, org.springframework.http.MediaType), and then calls writeInternal(T, org.springframework.http.HttpOutputMessage).

  Specified by:

  write in interface HttpMessageConverter<T>

  Parameters:

  t - the object to write to the output message. The type of this object must have previously been passed to the canWrite method of this interface, which must have returned true.

  contentType - the content type to use when writing. May be null to indicate that the default content type of the converter must be used. If not null, this media type must have previously been passed to the canWrite method of this interface, which must have returned true.

  outputMessage - the message to write to

  Throws:

  IOException - in case of I/O errors

  HttpMessageNotWritableException - in case of conversion errors

• addDefaultHeaders

  protected void addDefaultHeaders​(HttpHeaders headers,
                                   T t,
                                   MediaType contentType)
                            throws IOException

  Add default headers to the output message.

  This implementation delegates to getDefaultContentType(Object) if a content type was not provided, set if necessary the default character set, calls getContentLength(T, org.springframework.http.MediaType), and sets the corresponding headers.

  Throws:

  IOException

  Since:

  4.2

• getDefaultContentType

  protected MediaType getDefaultContentType​(T t)
                                     throws IOException

  Returns the default content type for the given type. Called when write(T, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage) is invoked without a specified content type parameter.

  By default, this returns the first element of the supportedMediaTypes property, if any. Can be overridden in subclasses.

  Parameters:

  t - the type to return the content type for

  Returns:

  the content type, or null if not known

  Throws:

  IOException

• getContentLength

  protected Long getContentLength​(T t,
                                  MediaType contentType)
                           throws IOException

  Returns the content length for the given type.

  By default, this returns null, meaning that the content length is unknown. Can be overridden in subclasses.

  Parameters:

  t - the type to return the content length for

  Returns:

  the content length, or null if not known

  Throws:

  IOException

• supports

  protected abstract boolean supports​(Class<?> clazz)

  Indicates whether the given class is supported by this converter.

  Parameters:

  clazz - the class to test for support

  Returns:

  true if supported; false otherwise

• readInternal

  protected abstract T readInternal​(Class<? extends T> clazz,
                                    HttpInputMessage inputMessage)
                             throws IOException,
                                    HttpMessageNotReadableException

  Abstract template method that reads the actual object. Invoked from read(java.lang.Class<? extends T>, org.springframework.http.HttpInputMessage).

  Parameters:

  clazz - the type of object to return

  inputMessage - the HTTP input message to read from

  Returns:

  the converted object

  Throws:

  IOException - in case of I/O errors

  HttpMessageNotReadableException - in case of conversion errors

• writeInternal

  protected abstract void writeInternal​(T t,
                                        HttpOutputMessage outputMessage)
                                 throws IOException,
                                        HttpMessageNotWritableException

  Abstract template method that writes the actual body. Invoked from write(T, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage).

  Parameters:

  t - the object to write to the output message

  outputMessage - the HTTP output message to write to

  Throws:

  IOException - in case of I/O errors

  HttpMessageNotWritableException - in case of conversion errors