AbstractMessageConverter (Spring Framework 5.2.8.RELEASE API)

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 for SmartMessageConverter 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

Field Summary

Fields
Modifier and Type Field and Description

protected Log logger

Fields
Modifier and Type	Field and Description
`protected Log`	`logger`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractMessageConverter(Collection<MimeType> supportedMimeTypes)` Constructor with a Collection of MIME types.
`protected`	`AbstractMessageConverter(MimeType... supportedMimeTypes)` Constructor with one or more MIME types via vararg.
`protected`	`AbstractMessageConverter(MimeType supportedMimeType)` Constructor with a single MIME type.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`addSupportedMimeTypes(MimeType... supportedMimeTypes)` Allows sub-classes 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 a `Message` from a serialized form to a typed Object of the specified target class.
`Object`	`fromMessage(Message<?> message, Class<?> targetClass, Object conversionHint)` A variant of `MessageConverter.fromMessage(Message, Class)` which takes an extra conversion context as an argument, allowing to take e.g.
`ContentTypeResolver`	`getContentTypeResolver()` Return the configured `ContentTypeResolver`.
`protected MimeType`	`getDefaultContentType(Object payload)` Returns 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 the `ContentTypeResolver` 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 a `Message`.
`void`	`setStrictContentTypeMatch(boolean strictContentTypeMatch)` Whether this converter should convert messages for which no content type could be resolved through the configured `ContentTypeResolver`.
`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 a `Message` whose payload is the result of converting the given payload Object to serialized form.
`Message<?>`	`toMessage(Object payload, MessageHeaders headers, Object conversionHint)` A variant of `MessageConverter.toMessage(Object, MessageHeaders)` which takes an extra conversion context as an argument, allowing to take e.g.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - logger
```
protected final Log logger
```
- 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 sub-classes to add more supported mime types.
    
    Since:
    
    5.2.2
  - setContentTypeResolver
```
public void setContentTypeResolver(@Nullable
                                   ContentTypeResolver resolver)
```
    Configure the ContentTypeResolver to use to resolve the content type of an input message.
    Note that if no resolver is configured, then strictContentTypeMatch should be left as false (the default) or otherwise this converter will ignore all messages.
    By default, a DefaultContentTypeResolver instance is used.
  - getContentTypeResolver
```
@Nullable
public ContentTypeResolver getContentTypeResolver()
```
    Return the configured ContentTypeResolver.
  - setStrictContentTypeMatch
```
public void setStrictContentTypeMatch(boolean strictContentTypeMatch)
```
    Whether this converter should convert messages for which no content type could be resolved through the configured ContentTypeResolver.
    A converter can configured to be strict only when a contentTypeResolver is configured and the list of supportedMimeTypes is not be empty.
    When this flag is set to true, supportsMimeType(MessageHeaders) will return false if the contentTypeResolver 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 a Message.
    The default value is byte[].
    
    Parameters:
    
    payloadClass - either byte[] or String
  - getSerializedPayloadClass
```
public Class<?> getSerializedPayloadClass()
```
    Return the configured preferred serialization payload class.
  - getDefaultContentType
```
@Nullable
protected MimeType getDefaultContentType(Object payload)
```
    Returns the default content type for the payload. Called when toMessage(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 sub-classes.
    
    Parameters:
    
    payload - the payload being converted to message
    
    Returns:
    
    the content type, or null if not known
  - fromMessage
```
@Nullable
public final Object fromMessage(Message<?> message,
                                          Class<?> targetClass)
```
    Description copied from interface: MessageConverter
    
    Convert the payload of a Message from a serialized form to a typed Object of the specified target class. The MessageHeaders.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 interface MessageConverter
    
    Parameters:
    
    message - the input message
    
    targetClass - 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 of MessageConverter.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 interface SmartMessageConverter
    
    Parameters:
    
    message - the input message
    
    targetClass - the target class for the conversion
    
    conversionHint - an extra object passed to the MessageConverter, e.g. the associated MethodParameter (may be null}
    
    Returns:
    
    the result of the conversion, or null if the converter cannot perform the conversion
    
    See Also:
    
    MessageConverter.fromMessage(Message, Class)
  - canConvertFrom
```
protected boolean canConvertFrom(Message<?> message,
                                 Class<?> targetClass)
```
  - toMessage
```
@Nullable
public final Message<?> toMessage(Object payload,
                                            @Nullable
                                            MessageHeaders headers)
```
    Description copied from interface: MessageConverter
    
    Create a Message whose payload is the result of converting the given payload Object to serialized form. The optional MessageHeaders parameter may contain a MessageHeaders.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 interface MessageConverter
    
    Parameters:
    
    payload - the Object to convert
    
    headers - optional headers for the message (may be null)
    
    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 of MessageConverter.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 interface SmartMessageConverter
    
    Parameters:
    
    payload - the Object to convert
    
    headers - optional headers for the message (may be null)
    
    conversionHint - an extra object passed to the MessageConverter, e.g. the associated MethodParameter (may be null}
    
    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)
  - canConvertTo
```
protected boolean canConvertTo(Object payload,
                               @Nullable
                               MessageHeaders headers)
```
  - supportsMimeType
```
protected boolean supportsMimeType(@Nullable
                                   MessageHeaders headers)
```
  - getMimeType
```
@Nullable
protected MimeType getMimeType(@Nullable
                                         MessageHeaders headers)
```
  - 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 message
    
    targetClass - the target class for the conversion
    
    conversionHint - an extra object passed to the MessageConverter, e.g. the associated MethodParameter (may be null}
    
    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 convert
    
    headers - optional headers for the message (may be null)
    
    conversionHint - an extra object passed to the MessageConverter, e.g. the associated MethodParameter (may be null}
    
    Returns:
    
    the resulting payload for the message, or null if the converter cannot perform the conversion
    
    Since:
    
    4.2

Class AbstractMessageConverter

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

logger

Constructor Detail

AbstractMessageConverter

AbstractMessageConverter

AbstractMessageConverter

Method Detail

getSupportedMimeTypes

addSupportedMimeTypes

setContentTypeResolver

getContentTypeResolver

setStrictContentTypeMatch

isStrictContentTypeMatch

setSerializedPayloadClass

getSerializedPayloadClass

getDefaultContentType

fromMessage

fromMessage

canConvertFrom

toMessage

toMessage

canConvertTo

supportsMimeType

getMimeType

supports

convertFromInternal

convertToInternal