com.fasterxml.jackson.databind.module.SimpleModule Maven / Gradle / Ivy
package com.fasterxml.jackson.databind.module;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier;
import com.fasterxml.jackson.databind.deser.ValueInstantiator;
import com.fasterxml.jackson.databind.jsontype.NamedType;
import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
/**
* Vanilla {@link com.fasterxml.jackson.databind.Module} implementation that allows registration
* of serializers and deserializers, bean serializer
* and deserializer modifiers, registration of subtypes and mix-ins
* as well as some other commonly
* needed aspects (addition of custom {@link AbstractTypeResolver}s,
* {@link com.fasterxml.jackson.databind.deser.ValueInstantiator}s).
*
* NOTE: that [de]serializers are registered as "default" [de]serializers.
* As a result, they will have lower priority than the ones indicated through annotations on
* both Class and property-associated annotations -- for example,
* {@link com.fasterxml.jackson.databind.annotation.JsonDeserialize}.
* In cases where both module-based [de]serializers and annotation-based [de]serializers are registered,
* the [de]serializer specified by the annotation will take precedence.
*
* NOTE: although it is not expected that sub-types should need to
* override {@link #setupModule(SetupContext)} method, if they choose
* to do so they MUST call {@code super.setupModule(context);}
* to ensure that registration works as expected.
*
* WARNING: when registering {@link JsonSerializer}s and {@link JsonDeserializer}s,
* only type erased {@code Class} is compared: this means that usually you should
* NOT use this implementation for registering structured types such as
* {@link java.util.Collection}s or {@link java.util.Map}s: this because parametric
* type information will not be considered and you may end up having "wrong" handler
* for your type.
* What you need to do, instead, is to implement {@link com.fasterxml.jackson.databind.deser.Deserializers}
* and/or {@link com.fasterxml.jackson.databind.ser.Serializers} callbacks to match full type
* signatures (with {@link JavaType}).
*/
public class SimpleModule
extends com.fasterxml.jackson.databind.Module
implements java.io.Serializable
{
private static final long serialVersionUID = 1L; // 2.5.0
// 16-Jun-2021, tatu: For [databind#3110], generate actual unique ids
// for SimpleModule instances (System.identityHashCode(...) is close
// but not quite it...
private static final AtomicInteger MODULE_ID_SEQ = new AtomicInteger(1);
protected final String _name;
protected final Version _version;
/**
* Flag that indicates whether module was given an explicit name
* or not. Distinction is used to determine whether method
* {@link #getTypeId()} should return name (yes, if explicit) or
* {@code null} (if no explicit name was passed).
*
* @since 2.13
*/
protected final boolean _hasExplicitName;
protected SimpleSerializers _serializers = null;
protected SimpleDeserializers _deserializers = null;
protected SimpleSerializers _keySerializers = null;
protected SimpleKeyDeserializers _keyDeserializers = null;
/**
* Lazily-constructed resolver used for storing mappings from
* abstract classes to more specific implementing classes
* (which may be abstract or concrete)
*/
protected SimpleAbstractTypeResolver _abstractTypes = null;
/**
* Lazily-constructed resolver used for storing mappings from
* abstract classes to more specific implementing classes
* (which may be abstract or concrete)
*/
protected SimpleValueInstantiators _valueInstantiators = null;
/**
* @since 2.2
*/
protected BeanDeserializerModifier _deserializerModifier = null;
/**
* @since 2.2
*/
protected BeanSerializerModifier _serializerModifier = null;
/**
* Lazily-constructed map that contains mix-in definitions, indexed
* by target class, value being mix-in to apply.
*/
protected HashMap, Class> _mixins = null;
/**
* Set of subtypes to register, if any.
*/
protected LinkedHashSet _subtypes = null;
/**
* @since 2.3
*/
protected PropertyNamingStrategy _namingStrategy = null;
/*
/**********************************************************
/* Life-cycle: creation
/**********************************************************
*/
/**
* Constructors that should only be used for non-reusable
* convenience modules used by app code: "real" modules should
* use actual name and version number information.
*/
public SimpleModule() {
// can't chain when making reference to 'this'
// note: generate different name for direct instantiation, sub-classing;
// this to avoid collision in former case while still addressing
// [databind#3110]
_name = (getClass() == SimpleModule.class)
? "SimpleModule-"+MODULE_ID_SEQ.getAndIncrement()
: getClass().getName();
_version = Version.unknownVersion();
// 07-Jun-2021, tatu: [databind#3110] Not passed explicitly so...
_hasExplicitName = false;
}
/**
* Convenience constructor that will default version to
* {@link Version#unknownVersion()}.
*/
public SimpleModule(String name) {
this(name, Version.unknownVersion());
}
/**
* Convenience constructor that will use specified Version,
* including name from {@link Version#getArtifactId()}.
*/
public SimpleModule(Version version) {
this(version.getArtifactId(), version);
}
/**
* Constructor to use for actual reusable modules.
* ObjectMapper may use name as identifier to notice attempts
* for multiple registrations of the same module (although it
* does not have to).
*
* @param name Unique name of the module
* @param version Version of the module
*/
public SimpleModule(String name, Version version) {
_name = name;
_version = version;
// 07-Jun-2021, tatu: [databind#3110] Is passed explicitly (may be `null`)
_hasExplicitName = true;
}
/**
* @since 2.1
*/
public SimpleModule(String name, Version version,
Map,JsonDeserializer> deserializers) {
this(name, version, deserializers, null);
}
/**
* @since 2.1
*/
public SimpleModule(String name, Version version,
List> serializers) {
this(name, version, null, serializers);
}
/**
* @since 2.1
*/
public SimpleModule(String name, Version version,
Map,JsonDeserializer> deserializers,
List> serializers)
{
_name = name;
// 07-Jun-2021, tatu: [databind#3110] Is passed explicitly (may be `null`)
_hasExplicitName = true;
_version = version;
if (deserializers != null) {
_deserializers = new SimpleDeserializers(deserializers);
}
if (serializers != null) {
_serializers = new SimpleSerializers(serializers);
}
}
/**
* Since instances are likely to be custom, implementation returns
* null if (but only if!) this class is directly instantiated;
* but class name (default impl) for sub-classes.
*/
@Override
public Object getTypeId()
{
// 07-Jun-2021, tatu: [databind#3110] Return Type Id if name was
// explicitly given
if (_hasExplicitName) {
return _name;
}
// Otherwise behavior same as with 2.12: no registration id for "throw-away"
// instances (to avoid bogus conflicts if user just instantiates SimpleModule)
// Note: actually... always returning `supet.getTypeId()` should be fine since
// that would return generated id? Let's do that actually.
if (getClass() == SimpleModule.class) {
return _name;
}
// And for what it is worth, this should usually do the same and we could
// in fact always just return `_name`. But leaving as-is for now.
return super.getTypeId();
}
/*
/**********************************************************
/* Simple setters to allow overriding
/**********************************************************
*/
/**
* Resets all currently configured serializers.
*/
public void setSerializers(SimpleSerializers s) {
_serializers = s;
}
/**
* Resets all currently configured deserializers.
*/
public void setDeserializers(SimpleDeserializers d) {
_deserializers = d;
}
/**
* Resets all currently configured key serializers.
*/
public void setKeySerializers(SimpleSerializers ks) {
_keySerializers = ks;
}
/**
* Resets all currently configured key deserializers.
*/
public void setKeyDeserializers(SimpleKeyDeserializers kd) {
_keyDeserializers = kd;
}
/**
* Resets currently configured abstract type mappings
*/
public void setAbstractTypes(SimpleAbstractTypeResolver atr) {
_abstractTypes = atr;
}
/**
* Resets all currently configured value instantiators
*/
public void setValueInstantiators(SimpleValueInstantiators svi) {
_valueInstantiators = svi;
}
/**
* @since 2.2
*/
public SimpleModule setDeserializerModifier(BeanDeserializerModifier mod) {
_deserializerModifier = mod;
return this;
}
/**
* @since 2.2
*/
public SimpleModule setSerializerModifier(BeanSerializerModifier mod) {
_serializerModifier = mod;
return this;
}
/**
* @since 2.3
*/
protected SimpleModule setNamingStrategy(PropertyNamingStrategy naming) {
_namingStrategy = naming;
return this;
}
/*
/**********************************************************
/* Configuration methods, adding serializers
/**********************************************************
*/
/**
* Method for adding serializer to handle type that the serializer claims to handle
* (see {@link JsonSerializer#handledType()}).
*
* WARNING! Type matching only uses type-erased {@code Class} and should NOT
* be used when registering serializers for generic types like
* {@link java.util.Collection} and {@link java.util.Map}.
*
* WARNING! "Last one wins" rule is applied.
* Possible earlier addition of a serializer for a given Class will be replaced.
*
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*/
public SimpleModule addSerializer(JsonSerializer ser)
{
_checkNotNull(ser, "serializer");
if (_serializers == null) {
_serializers = new SimpleSerializers();
}
_serializers.addSerializer(ser);
return this;
}
/**
* Method for adding serializer to handle values of specific type.
*
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*
* WARNING! Type matching only uses type-erased {@code Class} and should NOT
* be used when registering serializers for generic types like
* {@link java.util.Collection} and {@link java.util.Map}.
*
* WARNING! "Last one wins" rule is applied.
* Possible earlier addition of a serializer for a given Class will be replaced.
*
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*/
public SimpleModule addSerializer(Class type, JsonSerializer ser)
{
_checkNotNull(type, "type to register serializer for");
_checkNotNull(ser, "serializer");
if (_serializers == null) {
_serializers = new SimpleSerializers();
}
_serializers.addSerializer(type, ser);
return this;
}
/**
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*/
public SimpleModule addKeySerializer(Class type, JsonSerializer ser)
{
_checkNotNull(type, "type to register key serializer for");
_checkNotNull(ser, "key serializer");
if (_keySerializers == null) {
_keySerializers = new SimpleSerializers();
}
_keySerializers.addSerializer(type, ser);
return this;
}
/*
/**********************************************************
/* Configuration methods, adding deserializers
/**********************************************************
*/
/**
* Method for adding deserializer to handle specified type.
*
* WARNING! Type matching only uses type-erased {@code Class} and should NOT
* be used when registering serializers for generic types like
* {@link java.util.Collection} and {@link java.util.Map}.
*
* WARNING! "Last one wins" rule is applied.
* Possible earlier addition of a serializer for a given Class will be replaced.
*
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*/
public SimpleModule addDeserializer(Class type, JsonDeserializer deser)
{
_checkNotNull(type, "type to register deserializer for");
_checkNotNull(deser, "deserializer");
if (_deserializers == null) {
_deserializers = new SimpleDeserializers();
}
_deserializers.addDeserializer(type, deser);
return this;
}
/**
* NOTE: This method registers "default" (de)serializers only. See a note on precedence in class JavaDoc.
*/
public SimpleModule addKeyDeserializer(Class type, KeyDeserializer deser)
{
_checkNotNull(type, "type to register key deserializer for");
_checkNotNull(deser, "key deserializer");
if (_keyDeserializers == null) {
_keyDeserializers = new SimpleKeyDeserializers();
}
_keyDeserializers.addDeserializer(type, deser);
return this;
}
/*
/**********************************************************
/* Configuration methods, type mapping
/**********************************************************
*/
/**
* Lazily-constructed resolver used for storing mappings from
* abstract classes to more specific implementing classes
* (which may be abstract or concrete)
*/
public SimpleModule addAbstractTypeMapping(Class superType,
Class subType)
{
_checkNotNull(superType, "abstract type to map");
_checkNotNull(subType, "concrete type to map to");
if (_abstractTypes == null) {
_abstractTypes = new SimpleAbstractTypeResolver();
}
// note: addMapping() will verify arguments
_abstractTypes = _abstractTypes.addMapping(superType, subType);
return this;
}
/**
* Method for adding set of subtypes to be registered with
* {@link ObjectMapper}
* this is an alternative to using annotations in super type to indicate subtypes.
*/
public SimpleModule registerSubtypes(Class ... subtypes)
{
if (_subtypes == null) {
_subtypes = new LinkedHashSet<>();
}
for (Class subtype : subtypes) {
_checkNotNull(subtype, "subtype to register");
_subtypes.add(new NamedType(subtype));
}
return this;
}
/**
* Method for adding set of subtypes (along with type name to use) to be registered with
* {@link ObjectMapper}
* this is an alternative to using annotations in super type to indicate subtypes.
*/
public SimpleModule registerSubtypes(NamedType ... subtypes)
{
if (_subtypes == null) {
_subtypes = new LinkedHashSet<>();
}
for (NamedType subtype : subtypes) {
_checkNotNull(subtype, "subtype to register");
_subtypes.add(subtype);
}
return this;
}
/**
* Method for adding set of subtypes (along with type name to use) to be registered with
* {@link ObjectMapper}
* this is an alternative to using annotations in super type to indicate subtypes.
*
* @since 2.9
*/
public SimpleModule registerSubtypes(Collection> subtypes)
{
if (_subtypes == null) {
_subtypes = new LinkedHashSet<>();
}
for (Class subtype : subtypes) {
_checkNotNull(subtype, "subtype to register");
_subtypes.add(new NamedType(subtype));
}
return this;
}
/*
/**********************************************************
/* Configuration methods, add other handlers
/**********************************************************
*/
/**
* Method for registering {@link ValueInstantiator} to use when deserializing
* instances of type beanType.
*
* Instantiator is
* registered when module is registered for ObjectMapper.
*/
public SimpleModule addValueInstantiator(Class beanType, ValueInstantiator inst)
{
_checkNotNull(beanType, "class to register value instantiator for");
_checkNotNull(inst, "value instantiator");
if (_valueInstantiators == null) {
_valueInstantiators = new SimpleValueInstantiators();
}
_valueInstantiators = _valueInstantiators.addValueInstantiator(beanType, inst);
return this;
}
/**
* Method for specifying that annotations define by mixinClass
* should be "mixed in" with annotations that targetType
* has (as if they were directly included on it!).
*
* Mix-in annotations are
* registered when module is registered for ObjectMapper.
*/
public SimpleModule setMixInAnnotation(Class targetType, Class mixinClass)
{
_checkNotNull(targetType, "target type");
_checkNotNull(mixinClass, "mixin class");
if (_mixins == null) {
_mixins = new HashMap, Class>();
}
_mixins.put(targetType, mixinClass);
return this;
}
/*
/**********************************************************
/* Module impl
/**********************************************************
*/
@Override
public String getModuleName() {
return _name;
}
/**
* Standard implementation handles registration of all configured
* customizations: it is important that sub-classes call this
* implementation (usually before additional custom logic)
* if they choose to override it; otherwise customizations
* will not be registered.
*/
@Override
public void setupModule(SetupContext context)
{
if (_serializers != null) {
context.addSerializers(_serializers);
}
if (_deserializers != null) {
context.addDeserializers(_deserializers);
}
if (_keySerializers != null) {
context.addKeySerializers(_keySerializers);
}
if (_keyDeserializers != null) {
context.addKeyDeserializers(_keyDeserializers);
}
if (_abstractTypes != null) {
context.addAbstractTypeResolver(_abstractTypes);
}
if (_valueInstantiators != null) {
context.addValueInstantiators(_valueInstantiators);
}
if (_deserializerModifier != null) {
context.addBeanDeserializerModifier(_deserializerModifier);
}
if (_serializerModifier != null) {
context.addBeanSerializerModifier(_serializerModifier);
}
if (_subtypes != null && _subtypes.size() > 0) {
context.registerSubtypes(_subtypes.toArray(new NamedType[_subtypes.size()]));
}
if (_namingStrategy != null) {
context.setNamingStrategy(_namingStrategy);
}
if (_mixins != null) {
for (Map.Entry,Class> entry : _mixins.entrySet()) {
context.setMixInAnnotations(entry.getKey(), entry.getValue());
}
}
}
@Override
public Version version() { return _version; }
/*
/**********************************************************
/* Helper methods
/**********************************************************
*/
/**
* @since 2.9
*/
protected void _checkNotNull(Object thingy, String type)
{
if (thingy == null) {
throw new IllegalArgumentException(String.format(
"Cannot pass `null` as %s", type));
}
}
}