com.fitbur.jackson.databind.deser.std.EnumSetDeserializer Maven / Gradle / Ivy
package com.fitbur.jackson.databind.deser.std;
import java.io.IOException;
import java.util.*;
import com.fitbur.jackson.annotation.JsonFormat;
import com.fitbur.jackson.core.*;
import com.fitbur.jackson.databind.*;
import com.fitbur.jackson.databind.deser.ContextualDeserializer;
import com.fitbur.jackson.databind.jsontype.TypeDeserializer;
/**
* Standard deserializer for {@link EnumSet}s.
*
* Note: casting within this class is all messed up -- just could not figure out a way
* to properly deal with recursive definition of "EnumSet<K extends Enum<K>, V>
*/
@SuppressWarnings("rawtypes")
public class EnumSetDeserializer
extends StdDeserializer>
implements ContextualDeserializer
{
private static final long serialVersionUID = 1L; // since 2.5
protected final JavaType _enumType;
protected final Class _enumClass;
protected JsonDeserializer> _enumDeserializer;
/**
* Specific override for this instance (from proper, or global per-type overrides)
* to indicate whether single value may be taken to mean an unwrapped one-element array
* or not. If null, left to global defaults.
*
* @since 2.7
*/
protected final Boolean _unwrapSingle;
/*
/**********************************************************
/* Life-cycle
/**********************************************************
*/
@SuppressWarnings("unchecked" )
public EnumSetDeserializer(JavaType enumType, JsonDeserializer deser)
{
super(EnumSet.class);
_enumType = enumType;
_enumClass = (Class) enumType.getRawClass();
// sanity check
if (!_enumClass.isEnum()) {
throw new IllegalArgumentException("Type "+enumType+" not Java Enum type");
}
_enumDeserializer = (JsonDeserializer>) deser;
_unwrapSingle = null;
}
/**
* @since 2.7
*/
@SuppressWarnings("unchecked" )
protected EnumSetDeserializer(EnumSetDeserializer base,
JsonDeserializer deser, Boolean unwrapSingle) {
super(EnumSet.class);
_enumType = base._enumType;
_enumClass = base._enumClass;
_enumDeserializer = (JsonDeserializer>) deser;
_unwrapSingle = unwrapSingle;
}
public EnumSetDeserializer withDeserializer(JsonDeserializer deser) {
if (_enumDeserializer == deser) {
return this;
}
return new EnumSetDeserializer(this, deser, _unwrapSingle);
}
public EnumSetDeserializer withResolved(JsonDeserializer deser, Boolean unwrapSingle) {
if ((_unwrapSingle == unwrapSingle) && (_enumDeserializer == deser)) {
return this;
}
return new EnumSetDeserializer(this, deser, unwrapSingle);
}
/**
* Because of costs associated with constructing Enum resolvers,
* let's cache instances by default.
*/
@Override
public boolean isCachable() {
// One caveat: content deserializer should prevent caching
if (_enumType.getValueHandler() != null) {
return false;
}
return true;
}
@Override
public JsonDeserializer createContextual(DeserializationContext ctxt,
BeanProperty property) throws JsonMappingException
{
Boolean unwrapSingle = findFormatFeature(ctxt, property, EnumSet.class,
JsonFormat.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
JsonDeserializer deser = _enumDeserializer;
if (deser == null) {
deser = ctxt.findContextualValueDeserializer(_enumType, property);
} else { // if directly assigned, probably not yet contextual, so:
deser = ctxt.handleSecondaryContextualization(deser, property, _enumType);
}
return withResolved(deser, unwrapSingle);
}
/*
/**********************************************************
/* JsonDeserializer API
/**********************************************************
*/
@SuppressWarnings("unchecked")
@Override
public EnumSet deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
{
// Ok: must point to START_ARRAY (or equivalent)
if (!p.isExpectedStartArrayToken()) {
return handleNonArray(p, ctxt);
}
EnumSet result = constructSet();
JsonToken t;
try {
while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
/* What to do with nulls? Fail or ignore? Fail, for now
* (note: would fail if we passed it to EnumDeserializer, too,
* but in general nulls should never be passed to non-container
* deserializers)
*/
if (t == JsonToken.VALUE_NULL) {
throw ctxt.mappingException(_enumClass);
}
Enum value = _enumDeserializer.deserialize(p, ctxt);
/* 24-Mar-2012, tatu: As per [JACKSON-810], may actually get nulls;
* but EnumSets don't allow nulls so need to skip.
*/
if (value != null) {
result.add(value);
}
}
} catch (Exception e) {
throw JsonMappingException.wrapWithPath(e, result, result.size());
}
return result;
}
@Override
public Object deserializeWithType(JsonParser p, DeserializationContext ctxt,
TypeDeserializer typeDeserializer)
throws IOException, JsonProcessingException
{
return typeDeserializer.deserializeTypedFromArray(p, ctxt);
}
@SuppressWarnings("unchecked")
private EnumSet constructSet()
{
// superbly ugly... but apparently necessary
return EnumSet.noneOf(_enumClass);
}
@SuppressWarnings("unchecked")
protected EnumSet handleNonArray(JsonParser p, DeserializationContext ctxt)
throws IOException
{
boolean canWrap = (_unwrapSingle == Boolean.TRUE) ||
((_unwrapSingle == null) &&
ctxt.isEnabled(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY));
if (!canWrap) {
throw ctxt.mappingException(EnumSet.class);
}
EnumSet result = constructSet();
// First: since `null`s not allowed, slightly simpler...
if (p.hasToken(JsonToken.VALUE_NULL)) {
throw ctxt.mappingException(_enumClass);
}
try {
Enum value = _enumDeserializer.deserialize(p, ctxt);
if (value != null) {
result.add(value);
}
} catch (Exception e) {
throw JsonMappingException.wrapWithPath(e, result, result.size());
}
return result;
}
}