Package org.springframework.http.converter.json

Class AbstractJackson2HttpMessageConverter

java.lang.Object
org.springframework.http.converter.AbstractHttpMessageConverter<T>
org.springframework.http.converter.AbstractGenericHttpMessageConverter<Object>
org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter
All Implemented Interfaces:
GenericHttpMessageConverter<Object>, HttpMessageConverter<Object>
Direct Known Subclasses:
MappingJackson2CborHttpMessageConverter, MappingJackson2HttpMessageConverter, MappingJackson2SmileHttpMessageConverter, MappingJackson2XmlHttpMessageConverter, MappingJackson2YamlHttpMessageConverter
public abstract class AbstractJackson2HttpMessageConverter extends AbstractGenericHttpMessageConverter<Object>
Abstract base class for Jackson based and content type independent HttpMessageConverter implementations.
Since:
4.1
Author:
Arjen Poutsma, Keith Donald, Rossen Stoyanchev, Juergen Hoeller, Sebastien Deleuze, Sam Brannen
See Also:

  • Field Details

    • defaultObjectMapper

      protected com.fasterxml.jackson.databind.ObjectMapper defaultObjectMapper

  • Constructor Details

    • AbstractJackson2HttpMessageConverter

      protected AbstractJackson2HttpMessageConverter(com.fasterxml.jackson.databind.ObjectMapper objectMapper)

    • AbstractJackson2HttpMessageConverter

      protected AbstractJackson2HttpMessageConverter(com.fasterxml.jackson.databind.ObjectMapper objectMapper, MediaType supportedMediaType)

    • AbstractJackson2HttpMessageConverter

      protected AbstractJackson2HttpMessageConverter(com.fasterxml.jackson.databind.ObjectMapper objectMapper, MediaType... supportedMediaTypes)

  • Method Details

    • setSupportedMediaTypes

      public void setSupportedMediaTypes(List<MediaType> supportedMediaTypes)
      Description copied from class: AbstractHttpMessageConverter
      Set the list of MediaType objects supported by this converter.
      Overrides:
      setSupportedMediaTypes in class AbstractHttpMessageConverter<Object>

    • setObjectMapper

      public void setObjectMapper(com.fasterxml.jackson.databind.ObjectMapper objectMapper)
      Configure the main ObjectMapper to use for Object conversion. If not set, a default ObjectMapper instance is created.

      Setting a custom-configured ObjectMapper is one way to take further control of the JSON serialization process. For example, an extended SerializerFactory can be configured that provides custom serializers for specific types. Another option for refining the serialization process is to use Jackson's provided annotations on the types to be serialized, in which case a custom-configured ObjectMapper is unnecessary.

      See Also:

    • getObjectMapper

      public com.fasterxml.jackson.databind.ObjectMapper getObjectMapper()
      Return the main ObjectMapper in use.

    • registerObjectMappersForType

      public void registerObjectMappersForType(Class<?> clazz, Consumer<Map<MediaType,com.fasterxml.jackson.databind.ObjectMapper>> registrar)
      Configure the ObjectMapper instances to use for the given Class. This is useful when you want to deviate from the default ObjectMapper or have the ObjectMapper vary by MediaType.

      Note: Use of this method effectively turns off use of the default ObjectMapper and supportedMediaTypes for the given class. Therefore it is important for the mappings configured here to include every MediaType that must be supported for the given class.

      Parameters:
      clazz - the type of Object to register ObjectMapper instances for
      registrar - a consumer to populate or otherwise update the MediaType-to-ObjectMapper associations for the given Class
      Since:
      5.3.4

    • getObjectMappersForType

      public @Nullable Map<MediaType,com.fasterxml.jackson.databind.ObjectMapper> getObjectMappersForType(Class<?> clazz)
      Return ObjectMapper registrations for the given class, if any.
      Parameters:
      clazz - the class to look up for registrations for
      Returns:
      a map with registered MediaType-to-ObjectMapper registrations, or empty if in case of no registrations for the given class.
      Since:
      5.3.4

    • getSupportedMediaTypes

      public List<MediaType> getSupportedMediaTypes(Class<?> clazz)
      Description copied from interface: HttpMessageConverter
      Return the list of media types supported by this converter for the given class. The list may differ from HttpMessageConverter.getSupportedMediaTypes() if the converter does not support the given Class or if it supports it only for a subset of media types.
      Parameters:
      clazz - the type of class to check
      Returns:
      the list of media types supported for the given class

    • getMediaTypesForProblemDetail

      protected List<MediaType> getMediaTypesForProblemDetail()
      Return the supported media type(s) for ProblemDetail. By default, an empty list, unless overridden in subclasses.
      Since:
      6.0.5

    • setPrettyPrint

      public void setPrettyPrint(boolean prettyPrint)
      Whether to use the DefaultPrettyPrinter when writing JSON. This is a shortcut for setting up an ObjectMapper as follows: 
       ObjectMapper mapper = new ObjectMapper();
 mapper.configure(SerializationFeature.INDENT_OUTPUT, true);
 converter.setObjectMapper(mapper);

    • canRead

      public boolean canRead(Class<?> clazz, @Nullable MediaType mediaType)
      Description copied from class: AbstractHttpMessageConverter
      This implementation checks if the given class is supported, and if the supported media types include the given media type.
      Specified by:
      canRead in interface HttpMessageConverter<Object>
      Overrides:
      canRead in class AbstractHttpMessageConverter<Object>
      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

      public boolean canRead(Type type, @Nullable Class<?> contextClass, @Nullable MediaType mediaType)
      Description copied from interface: GenericHttpMessageConverter
      Indicates whether the given type can be read by this converter. This method should perform the same checks as HttpMessageConverter.canRead(Class, MediaType) with additional ones related to the generic type.
      Specified by:
      canRead in interface GenericHttpMessageConverter<Object>
      Overrides:
      canRead in class AbstractGenericHttpMessageConverter<Object>
      Parameters:
      type - the (potentially generic) type to test for readability
      contextClass - a context class for the target type, for example a class in which the target type appears in a method signature (can be null)
      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

    • canWrite

      public boolean canWrite(Class<?> clazz, @Nullable MediaType mediaType)
      Description copied from class: AbstractHttpMessageConverter
      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<Object>
      Overrides:
      canWrite in class AbstractHttpMessageConverter<Object>
      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

    • logWarningIfNecessary

      protected void logWarningIfNecessary(Type type, @Nullable Throwable cause)
      Determine whether to log the given exception coming from a ObjectMapper.canDeserialize(com.fasterxml.jackson.databind.JavaType) / ObjectMapper.canSerialize(java.lang.Class<?>) check.
      Parameters:
      type - the class that Jackson tested for (de-)serializability
      cause - the Jackson-thrown exception to evaluate (typically a JsonMappingException)
      Since:
      4.3

    • read

      public Object read(Type type, @Nullable Class<?> contextClass, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException
      Description copied from interface: GenericHttpMessageConverter
      Read an object of the given type from the given input message, and returns it.
      Parameters:
      type - the (potentially generic) type of object to return. This type must have previously been passed to the canRead method of this interface, which must have returned true.
      contextClass - a context class for the target type, for example a class in which the target type appears in a method signature (can be null)
      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

    • readInternal

      protected Object readInternal(Class<?> clazz, HttpInputMessage inputMessage) throws IOException, HttpMessageNotReadableException
      Description copied from class: AbstractHttpMessageConverter
      Abstract template method that reads the actual object. Invoked from AbstractHttpMessageConverter.read(java.lang.Class<? extends T>, org.springframework.http.HttpInputMessage).
      Specified by:
      readInternal in class AbstractHttpMessageConverter<Object>
      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

    • customizeReader

      protected com.fasterxml.jackson.databind.ObjectReader customizeReader(com.fasterxml.jackson.databind.ObjectReader reader, com.fasterxml.jackson.databind.JavaType javaType)
      Subclasses can use this method to customize ObjectReader used for reading values.
      Parameters:
      reader - the reader instance to customize
      javaType - the target type of element values to read to
      Returns:
      the customized ObjectReader
      Since:
      6.0

    • getCharset

      protected Charset getCharset(@Nullable MediaType contentType)
      Determine the charset to use for JSON input.

      By default this is either the charset from the input MediaType or otherwise falling back on UTF-8. Can be overridden in subclasses.

      Parameters:
      contentType - the content type of the HTTP input message
      Returns:
      the charset to use
      Since:
      5.1.18

    • writeInternal

      protected void writeInternal(Object object, @Nullable Type type, HttpOutputMessage outputMessage) throws IOException, HttpMessageNotWritableException
      Description copied from class: AbstractGenericHttpMessageConverter
      Abstract template method that writes the actual body. Invoked from AbstractGenericHttpMessageConverter.write(T, java.lang.reflect.Type, org.springframework.http.MediaType, org.springframework.http.HttpOutputMessage).
      Specified by:
      writeInternal in class AbstractGenericHttpMessageConverter<Object>
      Parameters:
      object - the object to write to the output message
      type - the type of object to write (may be null)
      outputMessage - the HTTP output message to write to
      Throws:
      IOException - in case of I/O errors
      HttpMessageNotWritableException - in case of conversion errors

    • customizeWriter

      protected com.fasterxml.jackson.databind.ObjectWriter customizeWriter(com.fasterxml.jackson.databind.ObjectWriter writer, @Nullable com.fasterxml.jackson.databind.JavaType javaType, @Nullable MediaType contentType)
      Subclasses can use this method to customize ObjectWriter used for writing values.
      Parameters:
      writer - the writer instance to customize
      javaType - the type of element values to write
      contentType - the selected media type
      Returns:
      the customized ObjectWriter
      Since:
      6.0

    • writePrefix

      protected void writePrefix(com.fasterxml.jackson.core.JsonGenerator generator, Object object) throws IOException
      Write a prefix before the main content.
      Parameters:
      generator - the generator to use for writing content.
      object - the object to write to the output message.
      Throws:
      IOException

    • writeSuffix

      protected void writeSuffix(com.fasterxml.jackson.core.JsonGenerator generator, Object object) throws IOException
      Write a suffix after the main content.
      Parameters:
      generator - the generator to use for writing content.
      object - the object to write to the output message.
      Throws:
      IOException

    • getJavaType

      protected com.fasterxml.jackson.databind.JavaType getJavaType(Type type, @Nullable Class<?> contextClass)
      Return the Jackson JavaType for the specified type and context class.
      Parameters:
      type - the generic type to return the Jackson JavaType for
      contextClass - a context class for the target type, for example a class in which the target type appears in a method signature (can be null)
      Returns:
      the Jackson JavaType

    • getJsonEncoding

      protected com.fasterxml.jackson.core.JsonEncoding getJsonEncoding(@Nullable MediaType contentType)
      Determine the JSON encoding to use for the given content type.
      Parameters:
      contentType - the media type as requested by the caller
      Returns:
      the JSON encoding to use (never null)

    • getDefaultContentType

      protected @Nullable MediaType getDefaultContentType(Object object) throws IOException
      Description copied from class: AbstractHttpMessageConverter
      Returns the default content type for the given type. Called when AbstractHttpMessageConverter.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.

      Overrides:
      getDefaultContentType in class AbstractHttpMessageConverter<Object>
      Parameters:
      object - the type to return the content type for
      Returns:
      the content type, or null if not known
      Throws:
      IOException

    • getContentLength

      protected @Nullable Long getContentLength(Object object, @Nullable MediaType contentType) throws IOException
      Description copied from class: AbstractHttpMessageConverter
      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.

      Overrides:
      getContentLength in class AbstractHttpMessageConverter<Object>
      Parameters:
      object - the type to return the content length for
      Returns:
      the content length, or null if not known
      Throws:
      IOException

    • supportsRepeatableWrites

      protected boolean supportsRepeatableWrites(Object o)
      Description copied from class: AbstractHttpMessageConverter
      Indicates whether this message converter can write the given object multiple times.

      The default implementation returns false.

      Overrides:
      supportsRepeatableWrites in class AbstractHttpMessageConverter<Object>
      Parameters:
      o - the object t
      Returns:
      true if t can be written repeatedly; false otherwise