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JooHyukKimJooHyukKim
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[Guava] Suppport simple deserialization of Cache (#116)
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‎guava/src/main/java/com/fasterxml/jackson/datatype/guava/GuavaDeserializers.java‎

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package com.fasterxml.jackson.datatype.guava;
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import com.google.common.base.Optional;
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import com.google.common.cache.Cache;
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import com.google.common.cache.ForwardingCache;
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import com.google.common.cache.LoadingCache;
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import com.google.common.collect.*;
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import com.google.common.hash.HashCode;
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import com.google.common.net.HostAndPort;
@@ -260,10 +263,42 @@ public JsonDeserializer<?> findMapLikeDeserializer(MapLikeType type,
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if (Table.class.isAssignableFrom(raw)) {
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// !!! TODO
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}
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// @since 2.16 : support Cache deserialization
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java.util.Optional<JsonDeserializer<?>> cacheDeserializer = findCacheDeserializer(raw, type, config,
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beanDesc, keyDeserializer, elementTypeDeserializer, elementDeserializer);
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if (cacheDeserializer.isPresent()) {
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return cacheDeserializer.get();
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}
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return null;
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}
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/**
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* Find matching implementation of {@link Cache} deserializers by checking
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* if the parameter {@code raw} type is assignable.
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*
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* NOTE: Make sure the cache implementations are checked in such a way that more concrete classes are
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* compared first before more abstract ones.
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*
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* @return An optional {@link JsonDeserializer} for the cache type, if found.
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* @since 2.16
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*/
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private java.util.Optional<JsonDeserializer<?>> findCacheDeserializer(Class<?> raw, MapLikeType type,
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DeserializationConfig config, BeanDescription beanDesc, KeyDeserializer keyDeserializer,
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TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer)
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{
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/* // Example implementations
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if (LoadingCache.class.isAssignableFrom(raw)) {
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return ....your implementation....;
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}
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*/
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if (Cache.class.isAssignableFrom(raw)) {
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return java.util.Optional.of(
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new SimpleCacheDeserializer(type, keyDeserializer, elementTypeDeserializer, elementDeserializer));
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}
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return java.util.Optional.empty();
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}
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@Override // since 2.7
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public JsonDeserializer<?> findReferenceDeserializer(ReferenceType refType,
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DeserializationConfig config, BeanDescription beanDesc,

‎guava/src/main/java/com/fasterxml/jackson/datatype/guava/SimpleCacheDeserializer.java‎

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package com.fasterxml.jackson.datatype.guava;
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import com.fasterxml.jackson.databind.JsonDeserializer;
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import com.fasterxml.jackson.databind.KeyDeserializer;
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import com.fasterxml.jackson.databind.deser.NullValueProvider;
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import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
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import com.fasterxml.jackson.databind.type.MapLikeType;
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import com.fasterxml.jackson.datatype.guava.deser.cache.GuavaCacheDeserializer;
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import com.google.common.cache.Cache;
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import com.google.common.cache.CacheBuilder;
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/**
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* {@link GuavaCacheDeserializer} class implementation for deserializing Guava {@link Cache} instances.
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*
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* @since 2.16
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*/
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public class SimpleCacheDeserializer
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extends GuavaCacheDeserializer<Cache<Object,Object>>
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{
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/*
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/**********************************************************
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/* Life-cycle
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/**********************************************************
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*/
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public SimpleCacheDeserializer(MapLikeType type, KeyDeserializer keyDeserializer,
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TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer)
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{
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super(type, keyDeserializer, elementTypeDeserializer, elementDeserializer);
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}
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public SimpleCacheDeserializer(MapLikeType type, KeyDeserializer keyDeserializer,
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TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer,
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NullValueProvider nvp)
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{
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super(type, keyDeserializer, elementTypeDeserializer, elementDeserializer, nvp);
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}
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/*
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/**********************************************************************
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/* Abstract method overrides
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/**********************************************************************
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*/
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@Override
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protected Cache<Object, Object> createCache() {
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return CacheBuilder.newBuilder().build();
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}
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@Override
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protected JsonDeserializer<?> _createContextual(MapLikeType t,
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KeyDeserializer kd, TypeDeserializer vtd, JsonDeserializer<?> vd, NullValueProvider np)
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{
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return new SimpleCacheDeserializer(t, kd, vtd, vd, np);
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}
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}

‎guava/src/main/java/com/fasterxml/jackson/datatype/guava/deser/cache/GuavaCacheDeserializer.java‎

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package com.fasterxml.jackson.datatype.guava.deser.cache;
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import com.fasterxml.jackson.core.JsonParser;
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import com.fasterxml.jackson.core.JsonToken;
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import com.fasterxml.jackson.databind.*;
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import com.fasterxml.jackson.databind.deser.ContextualDeserializer;
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import com.fasterxml.jackson.databind.deser.NullValueProvider;
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import com.fasterxml.jackson.databind.deser.impl.NullsConstantProvider;
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import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
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import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
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import com.fasterxml.jackson.databind.type.LogicalType;
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import com.fasterxml.jackson.databind.type.MapLikeType;
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import com.google.common.cache.Cache;
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import java.io.IOException;
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import java.lang.reflect.InvocationTargetException;
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public abstract class GuavaCacheDeserializer<T extends Cache<Object, Object>>
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extends StdDeserializer<T> implements ContextualDeserializer
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{
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private static final long serialVersionUID = 1L;
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private final MapLikeType type;
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private final KeyDeserializer keyDeserializer;
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private final TypeDeserializer elementTypeDeserializer;
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private final JsonDeserializer<?> elementDeserializer;
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/*
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* @since 2.16 : in 3.x demote to `ContainerDeserializerBase`
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*/
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private final NullValueProvider nullProvider;
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private final boolean skipNullValues;
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/*
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/**********************************************************
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/* Life-cycle
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/**********************************************************
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*/
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public GuavaCacheDeserializer(MapLikeType type, KeyDeserializer keyDeserializer,
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TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer) {
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this(type, keyDeserializer, elementTypeDeserializer, elementDeserializer, null);
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}
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public GuavaCacheDeserializer(MapLikeType type, KeyDeserializer keyDeserializer,
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TypeDeserializer elementTypeDeserializer, JsonDeserializer<?> elementDeserializer,
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NullValueProvider nvp)
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{
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super(type);
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this.type = type;
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this.keyDeserializer = keyDeserializer;
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this.elementTypeDeserializer = elementTypeDeserializer;
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this.elementDeserializer = elementDeserializer;
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this.nullProvider = nvp;
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skipNullValues = (nvp == null) ? false : NullsConstantProvider.isSkipper(nvp);
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}
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/*
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/**********************************************************
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/* Post-processing (contextualization)
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/**********************************************************
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*/
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@Override
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public JsonDeserializer<?> createContextual(DeserializationContext ctxt,
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BeanProperty property) throws JsonMappingException
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{
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KeyDeserializer kd = keyDeserializer;
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if (kd == null) {
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kd = ctxt.findKeyDeserializer(type.getKeyType(), property);
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}
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JsonDeserializer<?> valueDeser = elementDeserializer;
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final JavaType vt = type.getContentType();
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if (valueDeser == null) {
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valueDeser = ctxt.findContextualValueDeserializer(vt, property);
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} else { // if directly assigned, probably not yet contextual, so:
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valueDeser = ctxt.handleSecondaryContextualization(valueDeser, property, vt);
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}
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// Type deserializer is slightly different; must be passed, but needs to become contextual:
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TypeDeserializer vtd = elementTypeDeserializer;
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if (vtd != null) {
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vtd = vtd.forProperty(property);
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}
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return _createContextual(type, kd, vtd, valueDeser,
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findContentNullProvider(ctxt, property, valueDeser));
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}
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/*
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/**********************************************************************
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/* Abstract methods for subclasses
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/**********************************************************************
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*/
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protected abstract T createCache();
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protected abstract JsonDeserializer<?> _createContextual(MapLikeType t, KeyDeserializer kd,
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TypeDeserializer vtd, JsonDeserializer<?> vd, NullValueProvider np);
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/*
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/**********************************************************************
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/* Implementations
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/**********************************************************************
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*/
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@Override
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public LogicalType logicalType() {
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return LogicalType.Map;
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}
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@Override
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public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
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return deserializeContents(p, ctxt);
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}
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private T deserializeContents(JsonParser p, DeserializationContext ctxt)
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throws IOException
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{
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T cache = createCache();
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JsonToken currToken = p.currentToken();
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if (currToken != JsonToken.FIELD_NAME) {
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// 01-Mar-2023, tatu: [datatypes-collections#104] Handle empty Maps too
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if (currToken != JsonToken.END_OBJECT) {
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expect(p, JsonToken.START_OBJECT);
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currToken = p.nextToken();
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}
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}
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for (; currToken == JsonToken.FIELD_NAME; currToken = p.nextToken()) {
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final Object key;
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if (keyDeserializer != null) {
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key = keyDeserializer.deserializeKey(p.currentName(), ctxt);
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} else {
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key = p.currentName();
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}
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p.nextToken();
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final Object value;
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if (p.currentToken() == JsonToken.VALUE_NULL) {
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if (skipNullValues) {
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continue;
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}
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value = nullProvider.getNullValue(ctxt);
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} else if (elementTypeDeserializer != null) {
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value = elementDeserializer.deserializeWithType(p, ctxt, elementTypeDeserializer);
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} else {
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value = elementDeserializer.deserialize(p, ctxt);
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}
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cache.put(key, value);
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}
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return cache;
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}
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private void expect(JsonParser p, JsonToken token) throws IOException {
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if (p.getCurrentToken() != token) {
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throw new JsonMappingException(p, "Expecting " + token + " to start `Cache` value, found " + p.currentToken(),
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p.getCurrentLocation());
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}
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}
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}

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