Package org.springframework.http.converter.json

Class AbstractJsonHttpMessageConverter

java.lang.Object

org.springframework.http.converter.AbstractHttpMessageConverter<T>

org.springframework.http.converter.AbstractGenericHttpMessageConverter<Object>

org.springframework.http.converter.json.AbstractJsonHttpMessageConverter

All Implemented Interfaces:

GenericHttpMessageConverter<Object>, HttpMessageConverter<Object>

Direct Known Subclasses:

GsonHttpMessageConverter, JsonbHttpMessageConverter

public abstract class AbstractJsonHttpMessageConverter
extends AbstractGenericHttpMessageConverter<Object>

Common base class for plain JSON converters, for example, Gson and JSON-B.

Note that the Jackson converters have a dedicated class hierarchy due to their multi-format support.

Since:

5.0

Author:

Juergen Hoeller

See Also:

• GsonHttpMessageConverter
• JsonbHttpMessageConverter
• readInternal(Type, Reader)
• writeInternal(Object, Type, Writer)

Field Summary

Fields

Modifier and Type	Field	Description
static final Charset	DEFAULT_CHARSET	The default charset used by the converter.

Fields inherited from class org.springframework.http.converter.AbstractHttpMessageConverter

logger

Constructor Summary

Constructors

Constructor	Description
AbstractJsonHttpMessageConverter()

Method Summary

Modifier and Type	Method	Description
final Object	read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)	Read an object of the given type from the given input message, and returns it.
protected final Object	readInternal(Class<?> clazz, HttpInputMessage inputMessage)	Abstract template method that reads the actual object.
protected abstract Object	readInternal(Type resolvedType, Reader reader)	Template method that reads the JSON-bound object from the given Reader.
void	setJsonPrefix(String jsonPrefix)	Specify a custom prefix to use for JSON output.
void	setPrefixJson(boolean prefixJson)	Indicate whether the JSON output by this view should be prefixed with ")]}', ".
protected abstract void	writeInternal(Object object, Type type, Writer writer)	Template method that writes the JSON-bound object to the given Writer.
protected final void	writeInternal(Object object, Type type, HttpOutputMessage outputMessage)	Abstract template method that writes the actual body.

Methods inherited from class org.springframework.http.converter.AbstractGenericHttpMessageConverter

canRead, canWrite, supports, write, writeInternal

Methods inherited from class org.springframework.http.converter.AbstractHttpMessageConverter

addDefaultHeaders, canRead, canRead, canWrite, canWrite, getContentLength, getDefaultCharset, getDefaultContentType, getSupportedMediaTypes, read, setDefaultCharset, setSupportedMediaTypes, supportsRepeatableWrites, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.http.converter.HttpMessageConverter

canRead, canWrite, getSupportedMediaTypes, getSupportedMediaTypes, read, write

Field Details

DEFAULT_CHARSET

public static final Charset DEFAULT_CHARSET

The default charset used by the converter.

Constructor Details

AbstractJsonHttpMessageConverter

public AbstractJsonHttpMessageConverter()

Method Details

setJsonPrefix

public void setJsonPrefix(String jsonPrefix)

Specify a custom prefix to use for JSON output. Default is none.

See Also:

• setPrefixJson(boolean)

setPrefixJson

public void setPrefixJson(boolean prefixJson)

Indicate whether the JSON output by this view should be prefixed with ")]}', ". Default is false.

Prefixing the JSON string in this manner is used to help prevent JSON Hijacking. The prefix renders the string syntactically invalid as a script so that it cannot be hijacked. This prefix should be stripped before parsing the string as JSON.

See Also:

• setJsonPrefix(java.lang.String)

read

public final 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 final 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

writeInternal

protected final 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

readInternal

protected abstract Object readInternal(Type resolvedType,
 Reader reader)
                                throws Exception

Template method that reads the JSON-bound object from the given Reader.

Parameters:

resolvedType - the resolved generic type

reader - the Reader to use

Returns:

the JSON-bound object

Throws:

Exception - in case of read/parse failures

writeInternal

protected abstract void writeInternal(Object object,
 @Nullable
 Type type,
 Writer writer)
                               throws Exception

Template method that writes the JSON-bound object to the given Writer.

Parameters:

object - the object to write to the output message

type - the type of object to write (may be null)

writer - the Writer to use

Throws:

Exception - in case of write failures