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package com.fasterxml.jackson.databind;

import java.util.Collection;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.cfg.MutableConfigOverride;
import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier;
import com.fasterxml.jackson.databind.deser.DeserializationProblemHandler;
import com.fasterxml.jackson.databind.deser.Deserializers;
import com.fasterxml.jackson.databind.deser.KeyDeserializers;
import com.fasterxml.jackson.databind.deser.ValueInstantiators;
import com.fasterxml.jackson.databind.introspect.ClassIntrospector;
import com.fasterxml.jackson.databind.jsontype.NamedType;
import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
import com.fasterxml.jackson.databind.ser.Serializers;
import com.fasterxml.jackson.databind.type.TypeFactory;
import com.fasterxml.jackson.databind.type.TypeModifier;
import java.util.Collections;

/**
 * Simple interface for extensions that can be registered with {@link ObjectMapper}
 * to provide a well-defined set of extensions to default functionality; such as
 * support for new data types.
 */
public abstract class Module
    implements Versioned
{
    /*
    /**********************************************************
    /* Simple accessors
    /**********************************************************
     */

    /**
     * Method that returns a display that can be used by Jackson
     * for informational purposes, as well as in associating extensions with
     * module that provides them.
     */
    public abstract String getModuleName();

    /**
     * Method that returns version of this module. Can be used by Jackson for
     * informational purposes.
     */
    @Override
    public abstract Version version();

    /**
     * Method that returns an id that may be used to determine if two {@link Module}
     * instances are considered to be of same type, for purpose of preventing
     * multiple registrations of "same type of" module
     * (see {@link com.fasterxml.jackson.databind.MapperFeature#IGNORE_DUPLICATE_MODULE_REGISTRATIONS})
     * If `null` is returned, every instance is considered unique.
     * If non-null value is returned, equality of id Objects is used to check whether
     * modules should be considered to be "of same type"
     *

* Default implementation returns value of class name ({@link Class#getName}). * * @since 2.5 */ public Object getTypeId() { return getClass().getName(); } /* /********************************************************** /* Life-cycle: registration /********************************************************** */ /** * Method called by {@link ObjectMapper} when module is registered. * It is called to let module register functionality it provides, * using callback methods passed-in context object exposes. */ public abstract void setupModule(SetupContext context); /** * Returns the list of dependent modules this module has, if any. * It is called to let modules register other modules as dependencies. * Modules returned will be registered before this module is registered, * in iteration order. * * @since 2.10 */ public Iterable getDependencies() { return Collections.emptyList(); } /* /********************************************************** /* Helper types /********************************************************** */ /** * Interface Jackson exposes to modules for purpose of registering * extended functionality. * Usually implemented by {@link ObjectMapper}, but modules should * NOT rely on this -- if they do require access to mapper instance, * they need to call {@link SetupContext#getOwner} method. */ public static interface SetupContext { /* /********************************************************** /* Simple accessors /********************************************************** */ /** * Method that returns version information about {@link ObjectMapper} * that implements this context. Modules can use this to choose * different settings or initialization order; or even decide to fail * set up completely if version is compatible with module. */ public Version getMapperVersion(); /** * Fallback access method that allows modules to refer to the * {@link ObjectMapper} that provided this context. * It should NOT be needed by most modules; and ideally should * not be used -- however, there may be cases where this may * be necessary due to various design constraints. *

* NOTE: use of this method is discouraged, as it allows access to * things Modules typically should not modify. It is included, however, * to allow access to new features in cases where Module API * has not yet been extended, or there are oversights. *

* Return value is chosen to not leak dependency to {@link ObjectMapper}; * however, instance will always be of that type. * This is why return value is declared generic, to allow caller to * specify context to often avoid casting. * * @since 2.0 */ public C getOwner(); /** * Accessor for finding {@link TypeFactory} that is currently configured * by the context. *

* NOTE: since it is possible that other modules might change or replace * TypeFactory, use of this method adds order-dependency for registrations. * * @since 2.0 */ public TypeFactory getTypeFactory(); public boolean isEnabled(MapperFeature f); public boolean isEnabled(DeserializationFeature f); public boolean isEnabled(SerializationFeature f); public boolean isEnabled(JsonFactory.Feature f); public boolean isEnabled(JsonParser.Feature f); public boolean isEnabled(JsonGenerator.Feature f); /* /********************************************************** /* Mutant accessors /********************************************************** */ /** * "Mutant accessor" for getting a mutable configuration override object for * given type, needed to add or change per-type overrides applied * to properties of given type. * Usage is through returned object by colling "setter" methods, which * directly modify override object and take effect directly. * For example you can do *

         *   mapper.configOverride(java.util.Date.class)
         *       .setFormat(JsonFormat.Value.forPattern("yyyy-MM-dd"));
         *
* to change the default format to use for properties of type * {@link java.util.Date} (possibly further overridden by per-property * annotations) * * @since 2.8 */ public MutableConfigOverride configOverride(Class type); /* /********************************************************** /* Handler registration; serializers/deserializers /********************************************************** */ /** * Method that module can use to register additional deserializers to use for * handling types. * * @param d Object that can be called to find deserializer for types supported * by module (null returned for non-supported types) */ public void addDeserializers(Deserializers d); /** * Method that module can use to register additional deserializers to use for * handling Map key values (which are separate from value deserializers because * they are always serialized from String values) */ public void addKeyDeserializers(KeyDeserializers s); /** * Method that module can use to register additional serializers to use for * handling types. * * @param s Object that can be called to find serializer for types supported * by module (null returned for non-supported types) */ public void addSerializers(Serializers s); /** * Method that module can use to register additional serializers to use for * handling Map key values (which are separate from value serializers because * they must write JsonToken.FIELD_NAME instead of String value). */ public void addKeySerializers(Serializers s); /* /********************************************************** /* Handler registration; other /********************************************************** */ /** * Method that module can use to register additional modifier objects to * customize configuration and construction of bean deserializers. * * @param mod Modifier to register */ public void addBeanDeserializerModifier(BeanDeserializerModifier mod); /** * Method that module can use to register additional modifier objects to * customize configuration and construction of bean serializers. * * @param mod Modifier to register */ public void addBeanSerializerModifier(BeanSerializerModifier mod); /** * Method that module can use to register additional * {@link AbstractTypeResolver} instance, to handle resolution of * abstract to concrete types (either by defaulting, or by materializing). * * @param resolver Resolver to add. */ public void addAbstractTypeResolver(AbstractTypeResolver resolver); /** * Method that module can use to register additional * {@link TypeModifier} instance, which can augment {@link com.fasterxml.jackson.databind.JavaType} * instances constructed by {@link com.fasterxml.jackson.databind.type.TypeFactory}. * * @param modifier to add */ public void addTypeModifier(TypeModifier modifier); /** * Method that module can use to register additional {@link com.fasterxml.jackson.databind.deser.ValueInstantiator}s, * by adding {@link ValueInstantiators} object that gets called when * instantatiator is needed by a deserializer. * * @param instantiators Object that can provide {@link com.fasterxml.jackson.databind.deser.ValueInstantiator}s for * constructing POJO values during deserialization */ public void addValueInstantiators(ValueInstantiators instantiators); /** * Method for replacing the default class introspector with a derived class that * overrides specific behavior. * * @param ci Derived class of ClassIntrospector with overriden behavior * * @since 2.2 */ public void setClassIntrospector(ClassIntrospector ci); /** * Method for registering specified {@link AnnotationIntrospector} as the highest * priority introspector (will be chained with existing introspector(s) which * will be used as fallbacks for cases this introspector does not handle) * * @param ai Annotation introspector to register. */ public void insertAnnotationIntrospector(AnnotationIntrospector ai); /** * Method for registering specified {@link AnnotationIntrospector} as the lowest * priority introspector, chained with existing introspector(s) and called * as fallback for cases not otherwise handled. * * @param ai Annotation introspector to register. */ public void appendAnnotationIntrospector(AnnotationIntrospector ai); /** * Method for registering specified classes as subtypes (of supertype(s) * they have) */ public void registerSubtypes(Class... subtypes); /** * Method for registering specified classes as subtypes (of supertype(s) * they have), using specified type names. */ public void registerSubtypes(NamedType... subtypes); /** * Method for registering specified classes as subtypes (of supertype(s) * they have) * * @since 2.9 */ public void registerSubtypes(Collection> subtypes); /** * Method used for defining mix-in annotations to use for augmenting * specified class or interface. * All annotations from * mixinSource are taken to override annotations * that target (or its supertypes) has. *

* Note: mix-ins are registered both for serialization and deserialization * (which can be different internally). *

* Note: currently only one set of mix-in annotations can be defined for * a single class; so if multiple modules register mix-ins, highest * priority one (last one registered) will have priority over other modules. * * @param target Class (or interface) whose annotations to effectively override * @param mixinSource Class (or interface) whose annotations are to * be "added" to target's annotations, overriding as necessary */ public void setMixInAnnotations(Class target, Class mixinSource); /** * Add a deserialization problem handler * * @param handler The deserialization problem handler */ public void addDeserializationProblemHandler(DeserializationProblemHandler handler); /** * Method that may be used to override naming strategy that is used * by {@link ObjectMapper}. * * @since 2.3 */ public void setNamingStrategy(PropertyNamingStrategy naming); } }





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