Package com.restfb

Class DefaultJsonMapper

java.lang.Object

com.restfb.DefaultJsonMapper

All Implemented Interfaces:

JsonMapper

public class DefaultJsonMapper
extends Object
implements JsonMapper

Default implementation of a JSON-to-Java mapper.

Author:

Mark Allen

Nested Class Summary

Nested classes/interfaces inherited from interface com.restfb.JsonMapper

JsonMapper.JsonMappingCompleted

Constructor Summary

Constructors

Constructor	Description
DefaultJsonMapper()	Creates a JSON mapper which will throw FacebookJsonMappingException whenever an error occurs when mapping JSON data to Java objects.

Method Summary

Modifier and Type	Method	Description
protected Set<String>	facebookFieldNamesWithMultipleMappings(List<ReflectionUtils.FieldWithAnnotation<Facebook>> fieldsWithAnnotation)	Finds any Facebook JSON fields that are mapped to more than 1 Java field.
protected String	getFacebookFieldName(ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation)	For a Java field annotated with the Facebook annotation, figure out what the corresponding Facebook JSON field name to map to it is.
protected void	invokeJsonMappingCompletedMethods(Object object)	Finds and invokes methods on object that are annotated with the @JsonMappingCompleted annotation.
protected void	logMultipleMappingFailedForField(String facebookFieldName, ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation, String json)	Dumps out a log message when one of a multiple-mapped Facebook field name JSON-to-Java mapping operation fails.
void	setFacebookClient(FacebookClient facebookClient)	adds a FacebookClient implementation to the mapper.
<T> List<T>	toJavaList(String json, Class<T> type)	Given a JSON string, create and return a new instance of a corresponding Java List which contains elements of type type.
<T> T	toJavaObject(String json, Class<T> type)	Given a JSON string, create and return a new instance of a corresponding Java object of type type.
protected Object	toJavaType(ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation, JsonObject jsonObject, String facebookFieldName)	Extracts JSON data for a field according to its Facebook annotation and returns it converted to the proper Java type.
String	toJson(Object object)	Given a Java object, create and return a JSON string that represents it.
String	toJson(Object object, boolean ignoreNullValuedProperties)	Given a Java object, create and return a JSON string that represents it.
protected JsonValue	toJsonInternal(Object object, boolean ignoreNullValuedProperties)	Recursively marshal the given object to JSON.
protected <T> T	toPrimitiveJavaType(String json, Class<T> type)	Given a json value of something like MyValue or 123 , return a representation of that value of type type.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultJsonMapper

public DefaultJsonMapper()

Creates a JSON mapper which will throw FacebookJsonMappingException whenever an error occurs when mapping JSON data to Java objects.

Method Detail

setFacebookClient

public void setFacebookClient(FacebookClient facebookClient)

Description copied from interface: JsonMapper

adds a FacebookClient implementation to the mapper.

This is especially useful for mapping json to Connection objects that need the client itself.

Specified by:

setFacebookClient in interface JsonMapper

Parameters:

facebookClient - that is used for Connection objects

toJavaList

public <T> List<T> toJavaList(String json,
                              Class<T> type)

Description copied from interface: JsonMapper

Given a JSON string, create and return a new instance of a corresponding Java List which contains elements of type type.

The Java type must have a no-argument constructor.

Specified by:

toJavaList in interface JsonMapper

Type Parameters:

T - Java type to map to for each element of the list.

Parameters:

json - The JSON to be mapped to a Java type.

type - Java type token.

Returns:

A Java object (of type List which contains elements of type type) representation of the JSON input.

toJavaObject

public <T> T toJavaObject(String json,
                          Class<T> type)

Description copied from interface: JsonMapper

Given a JSON string, create and return a new instance of a corresponding Java object of type type.

The Java type must have a no-argument constructor.

Specified by:

toJavaObject in interface JsonMapper

Type Parameters:

T - Java type to map to.

Parameters:

json - The JSON to be mapped to a Java type.

type - Java type token.

Returns:

A Java object (of type type) representation of the JSON input.

invokeJsonMappingCompletedMethods

protected void invokeJsonMappingCompletedMethods(Object object)
                                          throws IllegalAccessException,
                                                 InvocationTargetException

Finds and invokes methods on object that are annotated with the @JsonMappingCompleted annotation.

This will even work on private methods.

Parameters:

object - The object on which to invoke the method.

Throws:

IllegalAccessException - If unable to invoke the method.

InvocationTargetException - If unable to invoke the method.

logMultipleMappingFailedForField

protected void logMultipleMappingFailedForField(String facebookFieldName,
                                                ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation,
                                                String json)

Dumps out a log message when one of a multiple-mapped Facebook field name JSON-to-Java mapping operation fails.

Parameters:

facebookFieldName - The Facebook field name.

fieldWithAnnotation - The Java field to map to and its annotation.

json - The JSON that failed to map to the Java field.

getFacebookFieldName

protected String getFacebookFieldName(ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation)

For a Java field annotated with the Facebook annotation, figure out what the corresponding Facebook JSON field name to map to it is.

Parameters:

fieldWithAnnotation - A Java field annotated with the Facebook annotation.

Returns:

The Facebook JSON field name that should be mapped to this Java field.

facebookFieldNamesWithMultipleMappings

protected Set<String> facebookFieldNamesWithMultipleMappings(List<ReflectionUtils.FieldWithAnnotation<Facebook>> fieldsWithAnnotation)

Finds any Facebook JSON fields that are mapped to more than 1 Java field.

Parameters:

fieldsWithAnnotation - Java fields annotated with the Facebook annotation.

Returns:

Any Facebook JSON fields that are mapped to more than 1 Java field.

toJson

public String toJson(Object object)

Description copied from interface: JsonMapper

Given a Java object, create and return a JSON string that represents it.

The object's properties will be traversed recursively, allowing for arbitrarily complex JSON generation.

Specified by:

toJson in interface JsonMapper

Parameters:

object - The Java object to map to JSON. Can be a Javabean, List, or Map.

Returns:

A JSON string.

toJson

public String toJson(Object object,
                     boolean ignoreNullValuedProperties)

Description copied from interface: JsonMapper

Given a Java object, create and return a JSON string that represents it.

The object's properties will be traversed recursively, allowing for arbitrarily complex JSON generation.

Specified by:

toJson in interface JsonMapper

Parameters:

object - The Java object to map to JSON. Can be a Javabean, List, or Map.

ignoreNullValuedProperties - If true, no Javabean properties with null values will be included in the generated JSON.

Returns:

A JSON string.

toJsonInternal

protected JsonValue toJsonInternal(Object object,
                                   boolean ignoreNullValuedProperties)

Recursively marshal the given object to JSON.

Used by toJson(Object).

Parameters:

object - The object to marshal.

ignoreNullValuedProperties - If this is true, no Javabean properties with null values will be included in the generated JSON.

Returns:

JSON representation of the given object.

Throws:

FacebookJsonMappingException - If an error occurs while marshaling to JSON.

toPrimitiveJavaType

protected <T> T toPrimitiveJavaType(String json,
                                    Class<T> type)

Given a json value of something like MyValue or 123 , return a representation of that value of type type.

This is to support non-legal JSON served up by Facebook for API calls like Friends.get (example result: [222333,1240079]).

Type Parameters:

T - The Java type to map to.

Parameters:

json - The non-legal JSON to map to the Java type.

type - Type token.

Returns:

Java representation of json.

Throws:

FacebookJsonMappingException - If an error occurs while mapping JSON to Java.

toJavaType

protected Object toJavaType(ReflectionUtils.FieldWithAnnotation<Facebook> fieldWithAnnotation,
                            JsonObject jsonObject,
                            String facebookFieldName)

Extracts JSON data for a field according to its Facebook annotation and returns it converted to the proper Java type.

Parameters:

fieldWithAnnotation - The field/annotation pair which specifies what Java type to convert to.

jsonObject - "Raw" JSON object to pull data from.

facebookFieldName - Specifies what JSON field to pull "raw" data from.

Returns:

A

Throws:

ParseException - If an error occurs while mapping JSON to Java.

FacebookJsonMappingException - If an error occurs while mapping JSON to Java.