org.springframework.integration.json

Class ObjectToJsonTransformer

java.lang.Object

org.springframework.integration.context.IntegrationObjectSupport

org.springframework.integration.transformer.AbstractTransformer

org.springframework.integration.json.ObjectToJsonTransformer

All Implemented Interfaces:

Aware, BeanFactoryAware, BeanNameAware, InitializingBean, ApplicationContextAware, ExpressionCapable, NamedComponent, GenericTransformer<Message<?>,Message<?>>, Transformer

public class ObjectToJsonTransformer
extends AbstractTransformer

Transformer implementation that converts a payload instance into a JSON string representation. By default this transformer uses JsonObjectMapperProvider factory to get an instance of a Jackson or Jackson 2 JSON-processor JsonObjectMapper implementation depending on the jackson-databind or jackson-mapper-asl libs on the classpath. Any other JsonObjectMapper implementation can be provided.

Since version 3.0, adds headers to represent the object types that were mapped from (including one level of container and Map content types). These headers are compatible with the Spring AMQP Json type mapper such that messages mapped or converted by either technology are compatible. One difference, however, is the Spring AMQP converter, when converting to JSON, sets the header types to the class name. This transformer sets the header types to the class itself.

The compatibility is achieved because, when mapping the Spring Integration message in the outbound endpoint (via the DefaultAmqpHeaderMapper), the classes are converted to String at that time.

Note: the first element of container/map types are used to determine the container/map content types. If the first element is null, the type is set to Object.

Since:

2.0

Author:

Mark Fisher, James Carr, Oleg Zhurakousky, Gary Russell, Artem Bilan

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ObjectToJsonTransformer.ResultType

Field Summary

Fields

Modifier and Type	Field and Description
static String	JSON_CONTENT_TYPE

Fields inherited from class org.springframework.integration.context.IntegrationObjectSupport

EXPRESSION_PARSER, logger

Constructor Summary

Constructors

Constructor and Description
ObjectToJsonTransformer()
ObjectToJsonTransformer(JsonObjectMapper<?,?> jsonObjectMapper)
ObjectToJsonTransformer(JsonObjectMapper<?,?> jsonObjectMapper, ObjectToJsonTransformer.ResultType resultType)
ObjectToJsonTransformer(ObjectToJsonTransformer.ResultType resultType)

Method Summary

Modifier and Type	Method and Description
protected Object	doTransform(Message<?> message) Subclasses must implement this method to provide the transformation logic.
String	getComponentType() Subclasses may implement this method to provide component type information.
void	setContentType(String contentType) Sets the content-type header value

Methods inherited from class org.springframework.integration.transformer.AbstractTransformer

transform

Methods inherited from class org.springframework.integration.context.IntegrationObjectSupport

afterPropertiesSet, extractTypeIfPossible, generateId, getApplicationContext, getApplicationContextId, getBeanDescription, getBeanFactory, getBeanName, getChannelResolver, getComponentName, getConversionService, getExpression, getIntegrationProperties, getIntegrationProperty, getMessageBuilderFactory, getTaskScheduler, isInitialized, onInit, setApplicationContext, setBeanFactory, setBeanName, setChannelResolver, setComponentName, setConversionService, setMessageBuilderFactory, setPrimaryExpression, setTaskScheduler, toString

Methods inherited from class java.lang.Object

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

Field Detail

JSON_CONTENT_TYPE

public static final String JSON_CONTENT_TYPE

See Also:

Constant Field Values

Constructor Detail

ObjectToJsonTransformer

public ObjectToJsonTransformer()

ObjectToJsonTransformer

public ObjectToJsonTransformer(JsonObjectMapper<?,?> jsonObjectMapper)

ObjectToJsonTransformer

public ObjectToJsonTransformer(ObjectToJsonTransformer.ResultType resultType)

ObjectToJsonTransformer

public ObjectToJsonTransformer(JsonObjectMapper<?,?> jsonObjectMapper,
                               ObjectToJsonTransformer.ResultType resultType)

Method Detail

setContentType

public void setContentType(String contentType)

Sets the content-type header value

Parameters:

contentType - The content type.

getComponentType

public String getComponentType()

Description copied from class: IntegrationObjectSupport

Subclasses may implement this method to provide component type information.

Specified by:

getComponentType in interface NamedComponent

Overrides:

getComponentType in class IntegrationObjectSupport

doTransform

protected Object doTransform(Message<?> message)

Description copied from class: AbstractTransformer

Subclasses must implement this method to provide the transformation logic. If the return value is itself a Message, it will be used as the result. Otherwise, any non-null return value will be used as the payload of the result Message.

Specified by:

doTransform in class AbstractTransformer

Parameters:

message - The message.

Returns:

The result of the transformation.