org.everit.json.schema.loader.internal

Class TypeBasedMultiplexer

java.lang.Object

org.everit.json.schema.loader.internal.TypeBasedMultiplexer

public class TypeBasedMultiplexer
extends Object

Used by org.everit.json.schema.loader.SchemaLoader.SchemaLoader during schema loading for type-based action selections. In other words this utility class is used for avoiding if..instanceof..casting constructs. Together with the TypeBasedMultiplexer.OnTypeConsumer implementations it forms a fluent API to deal with the parts of the JSON schema where multiple kind of values are valid for a given key.

Example usage: Object additProps = schemaJson.get("additionalProperties"); typeMultiplexer(additionalProps) .ifIs(JSONArray.class).then(arr -> {...if additProps is a JSONArray then process it... }) .ifObject().then(obj -> {...if additProps is a JSONArray then process it... }) .requireAny(); // throw a SchemaException if additProps is neither a JSONArray nor a JSONObject This class it NOT thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	TypeBasedMultiplexer.OnTypeConsumer<E> Created and used by TypeBasedMultiplexer to set actions (consumers) for matching classes.

Constructor Summary

Constructors

Constructor and Description
TypeBasedMultiplexer(Object obj) Constructor with null keyOfObj and null id.
TypeBasedMultiplexer(String keyOfObj, Object obj) Contstructor with null id.
TypeBasedMultiplexer(String keyOfObj, Object obj, URI id) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addResolutionScopeChangeListener(ResolutionScopeChangeListener resolutionScopeChangeListener)
<E> TypeBasedMultiplexer.OnTypeConsumer<E>	ifIs(Class<E> predicateClass) Creates a setter which will be invoked by orElse(Consumer) or requireAny() if obj is an instance of predicateClass.
TypeBasedMultiplexer.OnTypeConsumer<org.json.JSONObject>	ifObject() Creates a JSONObject consumer setter.
void	orElse(java.util.function.Consumer<Object> orElseConsumer) Checks if the obj is an instance of any previously set classes (by ifIs(Class) or ifObject()), performs the mapped action of found or invokes orElseConsumer with the obj.
void	requireAny() Checks if the obj is an instance of any previously set classes (by ifIs(Class) or ifObject()), performs the mapped action of found or throws with a SchemaException.

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeBasedMultiplexer

public TypeBasedMultiplexer(Object obj)

Constructor with null keyOfObj and null id.

Parameters:

obj - the object which' class is matched against the classes defined by ifIs(Class) (or ifObject()) calls.

TypeBasedMultiplexer

public TypeBasedMultiplexer(String keyOfObj,
                            Object obj)

Contstructor with null id.

Parameters:

keyOfObj - is an optional (nullable) string used by requireAny() to construct the message of the SchemaException if no appropriate consumer action is found.

obj - the object which' class is matched against the classes defined by ifIs(Class) (or ifObject()) calls.

TypeBasedMultiplexer

public TypeBasedMultiplexer(String keyOfObj,
                            Object obj,
                            URI id)

Constructor.

Parameters:

keyOfObj - is an optional (nullable) string used by requireAny() to construct the message of the SchemaException if no appropriate consumer action is found.

obj - the object which' class is matched against the classes defined by ifIs(Class) (or ifObject()) calls.

id - the scope id at the point where the multiplexer is initialized.

Method Detail

addResolutionScopeChangeListener

public void addResolutionScopeChangeListener(ResolutionScopeChangeListener resolutionScopeChangeListener)

ifIs

public <E> TypeBasedMultiplexer.OnTypeConsumer<E> ifIs(Class<E> predicateClass)

Creates a setter which will be invoked by orElse(Consumer) or requireAny() if obj is an instance of predicateClass.

Type Parameters:

E - the type represented by predicateClass.

Parameters:

predicateClass - the predicate class (the callback set by a subsequent TypeBasedMultiplexer.OnTypeConsumer.then(Consumer) will be executed if obj is an instance of predicateClass).

Returns:

an OnTypeConsumer implementation to be used to set the action performed if obj is an instance of predicateClass.

Throws:

IllegalArgumentException - if predicateClass is JSONObject. Use ifObject() for matching obj's class against JSONObject.

ifObject

public TypeBasedMultiplexer.OnTypeConsumer<org.json.JSONObject> ifObject()

Creates a JSONObject consumer setter.

The returned TypeBasedMultiplexer.OnTypeConsumer implementation will wrap the passed consumer action with an other consumer which properly maintains the SchemaLoader.id attribute, ie. if obj is a JSONObject instance and it has an id property then it will append this id value to SchemaLoader.id for the duration of the action execution, then it will restore the original id.

Returns:

an OnTypeConsumer implementation to be used to set the action performed if obj is a JSONObject instance.

orElse

public void orElse(java.util.function.Consumer<Object> orElseConsumer)

Checks if the obj is an instance of any previously set classes (by ifIs(Class) or ifObject()), performs the mapped action of found or invokes orElseConsumer with the obj.

Parameters:

orElseConsumer - the callback to be called if no types matched.

requireAny

public void requireAny()

Checks if the obj is an instance of any previously set classes (by ifIs(Class) or ifObject()), performs the mapped action of found or throws with a SchemaException.