Package org.springframework.http.converter.xml

Class Jaxb2CollectionHttpMessageConverter<T extends Collection>

java.lang.Object

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

org.springframework.http.converter.xml.AbstractXmlHttpMessageConverter<T>

org.springframework.http.converter.xml.AbstractJaxb2HttpMessageConverter<T>

org.springframework.http.converter.xml.Jaxb2CollectionHttpMessageConverter<T>

Type Parameters:

T - the converted object type

All Implemented Interfaces:

GenericHttpMessageConverter<T>, HttpMessageConverter<T>

public class Jaxb2CollectionHttpMessageConverter<T extends Collection>
extends AbstractJaxb2HttpMessageConverter<T>
implements GenericHttpMessageConverter<T>

An HttpMessageConverter that can read XML collections using JAXB2.

This converter can read collections that contain classes annotated with XmlRootElement and XmlType. Note that this converter does not support writing.

Since:

3.2

Author:

Arjen Poutsma, Rossen Stoyanchev, Sam Brannen

Field Summary

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

logger

Constructor Summary

Constructors

Constructor	Description
Jaxb2CollectionHttpMessageConverter()

Method Summary

Modifier and Type	Method	Description
boolean	canRead(Class<?> clazz, MediaType mediaType)	Always returns false since Jaxb2CollectionHttpMessageConverter required generic type information in order to read a Collection.
boolean	canRead(Type type, Class<?> contextClass, MediaType mediaType)	Indicates whether the given type can be read by this converter.
boolean	canWrite(Class<?> clazz, MediaType mediaType)	Always returns false since Jaxb2CollectionHttpMessageConverter does not convert collections to XML.
boolean	canWrite(Type type, Class<?> clazz, MediaType mediaType)	Always returns false since Jaxb2CollectionHttpMessageConverter does not convert collections to XML.
protected T	createCollection(Class<?> collectionClass)	Create a Collection of the given type, with the given initial capacity (if supported by the Collection type).
protected XMLInputFactory	createXmlInputFactory()	Create an XMLInputFactory that this converter will use to create XMLStreamReader and XMLEventReader objects.
T	read(Type type, Class<?> contextClass, HttpInputMessage inputMessage)	Read an object of the given type form the given input message, and returns it.
protected T	readFromSource(Class<? extends T> clazz, HttpHeaders headers, Source source)	Abstract template method called from AbstractHttpMessageConverter.read(Class, HttpInputMessage).
protected boolean	supports(Class<?> clazz)	Indicates whether the given class is supported by this converter.
void	write(T t, Type type, MediaType contentType, HttpOutputMessage outputMessage)	Write a given object to the given output message.
protected void	writeToResult(T t, HttpHeaders headers, Result result)	Abstract template method called from AbstractXmlHttpMessageConverter.writeInternal(Object, HttpOutputMessage).

Methods inherited from class org.springframework.http.converter.xml.AbstractJaxb2HttpMessageConverter

createMarshaller, createUnmarshaller, customizeMarshaller, customizeUnmarshaller, getJaxbContext

Methods inherited from class org.springframework.http.converter.xml.AbstractXmlHttpMessageConverter

readInternal, transform, writeInternal

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

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

getSupportedMediaTypes, getSupportedMediaTypes, read, write

Constructor Details

Jaxb2CollectionHttpMessageConverter

public Jaxb2CollectionHttpMessageConverter()

Method Details

canRead

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

Always returns false since Jaxb2CollectionHttpMessageConverter required generic type information in order to read a Collection.

Specified by:

canRead in interface HttpMessageConverter<T extends Collection>

Overrides:

canRead in class AbstractHttpMessageConverter<T extends Collection>

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)

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.

Jaxb2CollectionHttpMessageConverter can read a generic Collection where the generic type is a JAXB type annotated with XmlRootElement or XmlType.

Specified by:

canRead in interface GenericHttpMessageConverter<T extends Collection>

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)

Always returns false since Jaxb2CollectionHttpMessageConverter does not convert collections to XML.

Specified by:

canWrite in interface HttpMessageConverter<T extends Collection>

Overrides:

canWrite in class AbstractHttpMessageConverter<T extends Collection>

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

public boolean canWrite(@Nullable
 Type type,
 @Nullable
 Class<?> clazz,
 @Nullable
 MediaType mediaType)

Always returns false since Jaxb2CollectionHttpMessageConverter does not convert collections to XML.

Specified by:

canWrite in interface GenericHttpMessageConverter<T extends Collection>

Parameters:

type - the (potentially generic) type to test for writability (can be null if not specified)

clazz - the source object 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

supports

protected boolean supports(Class<?> clazz)

Description copied from class: AbstractHttpMessageConverter

Indicates whether the given class is supported by this converter.

Specified by:

supports in class AbstractHttpMessageConverter<T extends Collection>

Parameters:

clazz - the class to test for support

Returns:

true if supported; false otherwise

readFromSource

protected T readFromSource(Class<? extends T> clazz,
 HttpHeaders headers,
 Source source)
                    throws Exception

Description copied from class: AbstractXmlHttpMessageConverter

Abstract template method called from AbstractHttpMessageConverter.read(Class, HttpInputMessage).

Specified by:

readFromSource in class AbstractXmlHttpMessageConverter<T extends Collection>

Parameters:

clazz - the type of object to return

headers - the HTTP input headers

source - the HTTP input body

Returns:

the converted object

Throws:

Exception - in case of I/O or conversion errors

read

public T read(Type type,
 @Nullable
 Class<?> contextClass,
 HttpInputMessage inputMessage)
       throws IOException,
HttpMessageNotReadableException

Description copied from interface: GenericHttpMessageConverter

Read an object of the given type form the given input message, and returns it.

Specified by:

read in interface GenericHttpMessageConverter<T extends Collection>

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

createCollection

protected T createCollection(Class<?> collectionClass)

Create a Collection of the given type, with the given initial capacity (if supported by the Collection type).

Parameters:

collectionClass - the type of Collection to instantiate

Returns:

the created Collection instance

write

public void write(T t,
 @Nullable
 Type type,
 @Nullable
 MediaType contentType,
 HttpOutputMessage outputMessage)
           throws IOException,
HttpMessageNotWritableException

Description copied from interface: GenericHttpMessageConverter

Write a given object to the given output message.

Specified by:

write in interface GenericHttpMessageConverter<T extends Collection>

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.

type - the (potentially generic) type of object to write. This type must have previously been passed to the canWrite method of this interface, which must have returned true. Can be null if not specified.

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

writeToResult

protected void writeToResult(T t,
 HttpHeaders headers,
 Result result)
                      throws Exception

Description copied from class: AbstractXmlHttpMessageConverter

Abstract template method called from AbstractXmlHttpMessageConverter.writeInternal(Object, HttpOutputMessage).

Specified by:

writeToResult in class AbstractXmlHttpMessageConverter<T extends Collection>

Parameters:

t - the object to write to the output message

headers - the HTTP output headers

result - the HTTP output body

Throws:

Exception - in case of I/O or conversion errors

createXmlInputFactory

protected XMLInputFactory createXmlInputFactory()

Create an XMLInputFactory that this converter will use to create XMLStreamReader and XMLEventReader objects.

Can be overridden in subclasses, adding further initialization of the factory. The resulting factory is cached, so this method will only be called once.

See Also:

• StaxUtils.createDefensiveInputFactory()