org.nuxeo.ecm.core.io.marshallers.json

Class AbstractJsonReader<EntityType>

java.lang.Object

org.nuxeo.ecm.core.io.marshallers.json.AbstractJsonReader<EntityType>

Type Parameters:

EntityType - The expected Java type.

All Implemented Interfaces:

Marshaller<EntityType>, Reader<EntityType>

Direct Known Subclasses:

BlobJsonReader, DocumentPropertiesJsonReader, EntityJsonReader

@Supports(value="application/json")
public abstract class AbstractJsonReader<EntityType>
extends Object
implements Reader<EntityType>

Base class for Json Reader.

This class provides an easy way to create java object from json and also provides the current context: ctx. It provides you a JsonNode to manage the unmarshalling.

The use of this class optimize the JsonFactory usage especially when aggregating unmarshallers.

Since:

7.2

Field Summary

Fields

Modifier and Type	Field and Description
protected RenderingContext	ctx The current RenderingContext.
protected MarshallerRegistry	registry The marshaller registry.

Constructor Summary

Constructors

Constructor and Description
AbstractJsonReader()

Method Summary

Modifier and Type	Method and Description
boolean	accept(Class<?> clazz, Type genericType, javax.ws.rs.core.MediaType mediatype) Checks if this marshaller can handle the marshalling request.
protected org.codehaus.jackson.JsonNode	getNode(InputStream in, boolean getCurrentIfAvailable) Provide a JsonNode, try to get it from the context.
protected String	getStringField(org.codehaus.jackson.JsonNode jn, String elName) Try to get a string property of the given JsonNode.
EntityType	read(Class<?> clazz, Type genericType, javax.ws.rs.core.MediaType mediaType, InputStream in) Read the entity from in InputStream using mediatype format.
abstract EntityType	read(org.codehaus.jackson.JsonNode jn) Implement this method, read the entity data in the provided JsonNode and return corresponding java object.
protected <T> T	readEntity(Class<?> clazz, Type genericType, org.codehaus.jackson.JsonNode jn) Use this method to delegate the unmarshalling of a part or your Json to the MarshallerRegistry.

Methods inherited from class java.lang.Object

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

Field Detail

ctx

@Inject
protected RenderingContext ctx

The current RenderingContext.

registry

@Inject
protected MarshallerRegistry registry

The marshaller registry. You may use it to use other marshallers.

Constructor Detail

AbstractJsonReader

public AbstractJsonReader()

Method Detail

accept

public boolean accept(Class<?> clazz,
                      Type genericType,
                      javax.ws.rs.core.MediaType mediatype)

Description copied from interface: Marshaller

Checks if this marshaller can handle the marshalling request.

Please note it's useless to check that clazz is an instance of EntityType or if generic type and entity type are compatible (unlike JAX-RS which just checks the clazz, not the generic type). It's also useless to check Supports is compatible with mediatype. This is already done by the MarshallerRegistry

This method implementation can use injected properties. So you can check the current RenderingContext to accept or reject a marshalling request.

Specified by:

accept in interface Marshaller<EntityType>

Parameters:

clazz - The type to marshall.

genericType - The generic type to marshall.

mediatype - The managed mimetype.

Returns:

true if this converter handle the request, false otherwise.

read

public EntityType read(Class<?> clazz,
                       Type genericType,
                       javax.ws.rs.core.MediaType mediaType,
                       InputStream in)
                throws IOException

Description copied from interface: Reader

Read the entity from in InputStream using mediatype format.

This method implementation can use injected properties.

Specified by:

read in interface Reader<EntityType>

Parameters:

clazz - The requested marshalled class.

genericType - The requested marshalled generic type.

in - The input of this marshaller.

Throws:

IOException - If some error append while reading entity from in.

getNode

protected org.codehaus.jackson.JsonNode getNode(InputStream in,
                                                boolean getCurrentIfAvailable)
                                         throws IOException,
                                                org.codehaus.jackson.JsonParseException,
                                                org.codehaus.jackson.JsonProcessingException

Provide a JsonNode, try to get it from the context.

Parameters:

in - The current InputStream.

getCurrentIfAvailable - If true, try to get it from the context (if another marshaller already create it and call this marshaller).

Returns:

A valid JsonNode.

Throws:

IOException

org.codehaus.jackson.JsonParseException

org.codehaus.jackson.JsonProcessingException

Since:

7.2

read

public abstract EntityType read(org.codehaus.jackson.JsonNode jn)
                         throws IOException

Implement this method, read the entity data in the provided JsonNode and return corresponding java object.

Parameters:

jn - A ready to use JsonNode.

Returns:

The unmarshalled entity.

Throws:

IOException

Since:

7.2

readEntity

protected <T> T readEntity(Class<?> clazz,
                           Type genericType,
                           org.codehaus.jackson.JsonNode jn)
                    throws IOException

Use this method to delegate the unmarshalling of a part or your Json to the MarshallerRegistry. This will work only if a Json Reader is registered for the provided clazz and if the node format is the same as the one expected by the marshaller.

Parameters:

clazz - The expected Java class.

genericType - The generic type of the expected object: usefull if it's a generic List for example (use TypeUtils to create the parametrize type).

jn - The JsonNode to unmarshall.

Returns:

An object implementing the expected clazz.

Throws:

IOException

Since:

7.2

getStringField

protected String getStringField(org.codehaus.jackson.JsonNode jn,
                                String elName)

Try to get a string property of the given JsonNode. Return null if the node is null.

Parameters:

jn - The JsonNode to parse.

elName - The property name.

Returns:

The property text if it exists and it's a text, null otherwise.

Since:

7.2