Class AbstractMessageConverter
- java.lang.Object
- org.springframework.messaging.converter.AbstractMessageConverter
- All Implemented Interfaces:
MessageConverter
,SmartMessageConverter
- Direct Known Subclasses:
ByteArrayMessageConverter
,MappingJackson2MessageConverter
,MarshallingMessageConverter
,ProtobufMessageConverter
,StringMessageConverter
public abstract class AbstractMessageConverter extends Object implements SmartMessageConverter
Abstract base class forSmartMessageConverter
implementations including support for common properties and a partial implementation of the conversion methods, mainly to check if the converter supports the conversion based on the payload class and MIME type.- Since:
- 4.0
- Author:
- Rossen Stoyanchev, Sebastien Deleuze, Juergen Hoeller
Constructor Summary
Constructors Modifier Constructor Description protected
AbstractMessageConverter(Collection<MimeType> supportedMimeTypes)
Constructor with a Collection of MIME types.protected
AbstractMessageConverter(MimeType supportedMimeType)
Constructor with a single MIME type.protected
AbstractMessageConverter(MimeType... supportedMimeTypes)
Constructor with one or more MIME types via vararg.
Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected void
addSupportedMimeTypes(MimeType... supportedMimeTypes)
Allows subclasses to add more supported mime types.protected boolean
canConvertFrom(Message<?> message, Class<?> targetClass)
protected boolean
canConvertTo(Object payload, MessageHeaders headers)
protected Object
convertFromInternal(Message<?> message, Class<?> targetClass, Object conversionHint)
Convert the message payload from serialized form to an Object.protected Object
convertToInternal(Object payload, MessageHeaders headers, Object conversionHint)
Convert the payload object to serialized form.Object
fromMessage(Message<?> message, Class<?> targetClass)
Convert the payload of aMessage
from a serialized form to a typed Object of the specified target class.Object
fromMessage(Message<?> message, Class<?> targetClass, Object conversionHint)
A variant ofMessageConverter.fromMessage(Message, Class)
which takes an extra conversion context as an argument, allowing to take e.g.ContentTypeResolver
getContentTypeResolver()
Return the configuredContentTypeResolver
.protected MimeType
getDefaultContentType(Object payload)
Return the default content type for the payload.protected MimeType
getMimeType(MessageHeaders headers)
Class<?>
getSerializedPayloadClass()
Return the configured preferred serialization payload class.List<MimeType>
getSupportedMimeTypes()
Return the supported MIME types.boolean
isStrictContentTypeMatch()
Whether content type resolution must produce a value that matches one of the supported MIME types.void
setContentTypeResolver(ContentTypeResolver resolver)
Configure theContentTypeResolver
to use to resolve the content type of an input message.void
setSerializedPayloadClass(Class<?> payloadClass)
Configure the preferred serialization class to use (byte[] or String) when converting an Object payload to aMessage
.void
setStrictContentTypeMatch(boolean strictContentTypeMatch)
Whether this converter should convert messages for which no content type could be resolved through the configuredContentTypeResolver
.protected abstract boolean
supports(Class<?> clazz)
Whether the given class is supported by this converter.protected boolean
supportsMimeType(MessageHeaders headers)
Message<?>
toMessage(Object payload, MessageHeaders headers)
Create aMessage
whose payload is the result of converting the given payload Object to serialized form.Message<?>
toMessage(Object payload, MessageHeaders headers, Object conversionHint)
A variant ofMessageConverter.toMessage(Object, MessageHeaders)
which takes an extra conversion context as an argument, allowing to take e.g.
Constructor Detail
AbstractMessageConverter
protected AbstractMessageConverter(MimeType supportedMimeType)
Constructor with a single MIME type.- Parameters:
supportedMimeType
- the supported MIME type
AbstractMessageConverter
protected AbstractMessageConverter(MimeType... supportedMimeTypes)
Constructor with one or more MIME types via vararg.- Parameters:
supportedMimeTypes
- the supported MIME types- Since:
- 5.2.2
AbstractMessageConverter
protected AbstractMessageConverter(Collection<MimeType> supportedMimeTypes)
Constructor with a Collection of MIME types.- Parameters:
supportedMimeTypes
- the supported MIME types
Method Detail
getSupportedMimeTypes
public List<MimeType> getSupportedMimeTypes()
Return the supported MIME types.
addSupportedMimeTypes
protected void addSupportedMimeTypes(MimeType... supportedMimeTypes)
Allows subclasses to add more supported mime types.- Since:
- 5.2.2
setContentTypeResolver
public void setContentTypeResolver(@Nullable ContentTypeResolver resolver)
Configure theContentTypeResolver
to use to resolve the content type of an input message.Note that if no resolver is configured, then
strictContentTypeMatch
should be left asfalse
(the default) or otherwise this converter will ignore all messages.By default, a
DefaultContentTypeResolver
instance is used.
getContentTypeResolver
@Nullable public ContentTypeResolver getContentTypeResolver()
Return the configuredContentTypeResolver
.
setStrictContentTypeMatch
public void setStrictContentTypeMatch(boolean strictContentTypeMatch)
Whether this converter should convert messages for which no content type could be resolved through the configuredContentTypeResolver
.A converter can configured to be strict only when a
contentTypeResolver
is configured and the list ofsupportedMimeTypes
is not be empty.When this flag is set to
true
,supportsMimeType(MessageHeaders)
will returnfalse
if thecontentTypeResolver
is not defined or if no content-type header is present.
isStrictContentTypeMatch
public boolean isStrictContentTypeMatch()
Whether content type resolution must produce a value that matches one of the supported MIME types.
setSerializedPayloadClass
public void setSerializedPayloadClass(Class<?> payloadClass)
Configure the preferred serialization class to use (byte[] or String) when converting an Object payload to aMessage
.The default value is byte[].
- Parameters:
payloadClass
- either byte[] or String
getSerializedPayloadClass
public Class<?> getSerializedPayloadClass()
Return the configured preferred serialization payload class.
fromMessage
@Nullable public final Object fromMessage(Message<?> message, Class<?> targetClass)
Description copied from interface:MessageConverter
Convert the payload of aMessage
from a serialized form to a typed Object of the specified target class. TheMessageHeaders.CONTENT_TYPE
header should indicate the MIME type to convert from.If the converter does not support the specified media type or cannot perform the conversion, it should return
null
.- Specified by:
fromMessage
in interfaceMessageConverter
- Parameters:
message
- the input messagetargetClass
- the target class for the conversion- Returns:
- the result of the conversion, or
null
if the converter cannot perform the conversion
fromMessage
@Nullable public final Object fromMessage(Message<?> message, Class<?> targetClass, @Nullable Object conversionHint)
Description copied from interface:SmartMessageConverter
A variant ofMessageConverter.fromMessage(Message, Class)
which takes an extra conversion context as an argument, allowing to take e.g. annotations on a payload parameter into account.- Specified by:
fromMessage
in interfaceSmartMessageConverter
- Parameters:
message
- the input messagetargetClass
- the target class for the conversionconversionHint
- an extra object passed to theMessageConverter
, e.g. the associatedMethodParameter
(may benull
}- Returns:
- the result of the conversion, or
null
if the converter cannot perform the conversion - See Also:
MessageConverter.fromMessage(Message, Class)
toMessage
@Nullable public final Message<?> toMessage(Object payload, @Nullable MessageHeaders headers)
Description copied from interface:MessageConverter
Create aMessage
whose payload is the result of converting the given payload Object to serialized form. The optionalMessageHeaders
parameter may contain aMessageHeaders.CONTENT_TYPE
header to specify the target media type for the conversion and it may contain additional headers to be added to the message.If the converter does not support the specified media type or cannot perform the conversion, it should return
null
.- Specified by:
toMessage
in interfaceMessageConverter
- Parameters:
payload
- the Object to convertheaders
- optional headers for the message (may benull
)- Returns:
- the new message, or
null
if the converter does not support the Object type or the target media type
toMessage
@Nullable public final Message<?> toMessage(Object payload, @Nullable MessageHeaders headers, @Nullable Object conversionHint)
Description copied from interface:SmartMessageConverter
A variant ofMessageConverter.toMessage(Object, MessageHeaders)
which takes an extra conversion context as an argument, allowing to take e.g. annotations on a return type into account.- Specified by:
toMessage
in interfaceSmartMessageConverter
- Parameters:
payload
- the Object to convertheaders
- optional headers for the message (may benull
)conversionHint
- an extra object passed to theMessageConverter
, e.g. the associatedMethodParameter
(may benull
}- Returns:
- the new message, or
null
if the converter does not support the Object type or the target media type - See Also:
MessageConverter.toMessage(Object, MessageHeaders)
canConvertFrom
protected boolean canConvertFrom(Message<?> message, Class<?> targetClass)
canConvertTo
protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers)
supportsMimeType
protected boolean supportsMimeType(@Nullable MessageHeaders headers)
getMimeType
@Nullable protected MimeType getMimeType(@Nullable MessageHeaders headers)
getDefaultContentType
@Nullable protected MimeType getDefaultContentType(Object payload)
Return the default content type for the payload. Called whentoMessage(Object, MessageHeaders)
is invoked without message headers or without a content type header.By default, this returns the first element of the
supportedMimeTypes
, if any. Can be overridden in subclasses.- Parameters:
payload
- the payload being converted to a message- Returns:
- the content type, or
null
if not known
supports
protected abstract boolean supports(Class<?> clazz)
Whether the given class is supported by this converter.- Parameters:
clazz
- the class to test for support- Returns:
true
if supported;false
otherwise
convertFromInternal
@Nullable protected Object convertFromInternal(Message<?> message, Class<?> targetClass, @Nullable Object conversionHint)
Convert the message payload from serialized form to an Object.- Parameters:
message
- the input messagetargetClass
- the target class for the conversionconversionHint
- an extra object passed to theMessageConverter
, e.g. the associatedMethodParameter
(may benull
}- Returns:
- the result of the conversion, or
null
if the converter cannot perform the conversion - Since:
- 4.2
convertToInternal
@Nullable protected Object convertToInternal(Object payload, @Nullable MessageHeaders headers, @Nullable Object conversionHint)
Convert the payload object to serialized form.- Parameters:
payload
- the Object to convertheaders
- optional headers for the message (may benull
)conversionHint
- an extra object passed to theMessageConverter
, e.g. the associatedMethodParameter
(may benull
}- Returns:
- the resulting payload for the message, or
null
if the converter cannot perform the conversion - Since:
- 4.2