com.fasterxml.jackson.databind.deser.std.StringArrayDeserializer Maven / Gradle / Ivy
The newest version!
package com.fasterxml.jackson.databind.deser.std;
import java.io.IOException;
import java.util.Objects;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.annotation.JacksonStdImpl;
import com.fasterxml.jackson.databind.cfg.CoercionAction;
import com.fasterxml.jackson.databind.cfg.CoercionInputShape;
import com.fasterxml.jackson.databind.deser.ContextualDeserializer;
import com.fasterxml.jackson.databind.deser.NullValueProvider;
import com.fasterxml.jackson.databind.deser.impl.NullsConstantProvider;
import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
import com.fasterxml.jackson.databind.type.LogicalType;
import com.fasterxml.jackson.databind.util.AccessPattern;
import com.fasterxml.jackson.databind.util.ObjectBuffer;
/**
* Separate implementation for serializing String arrays (instead of
* using {@link ObjectArrayDeserializer}.
* Used if (and only if) no custom value deserializers are used.
*/
@JacksonStdImpl
public final class StringArrayDeserializer
// 28-Oct-2016, tatu: Should do this:
// extends ContainerDeserializerBase
// but for now won't:
extends StdDeserializer
implements ContextualDeserializer
{
private static final long serialVersionUID = 2L;
private final static String[] NO_STRINGS = new String[0];
public final static StringArrayDeserializer instance = new StringArrayDeserializer();
/**
* Value serializer to use, if not the standard one (which is inlined)
*/
protected JsonDeserializer _elementDeserializer;
/**
* Handler we need for dealing with null values as elements
*
* @since 2.9
*/
protected final NullValueProvider _nullProvider;
/**
* 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;
/**
* Marker flag set if the _nullProvider indicates that all null
* content values should be skipped (instead of being possibly converted).
*
* @since 2.9
*/
protected final boolean _skipNullValues;
public StringArrayDeserializer() {
this(null, null, null);
}
@SuppressWarnings("unchecked")
protected StringArrayDeserializer(JsonDeserializer deser,
NullValueProvider nuller, Boolean unwrapSingle) {
super(String[].class);
_elementDeserializer = (JsonDeserializer) deser;
_nullProvider = nuller;
_unwrapSingle = unwrapSingle;
_skipNullValues = NullsConstantProvider.isSkipper(nuller);
}
@Override // since 2.12
public LogicalType logicalType() {
return LogicalType.Array;
}
@Override // since 2.9
public Boolean supportsUpdate(DeserializationConfig config) {
return Boolean.TRUE;
}
@Override // since 2.9
public AccessPattern getEmptyAccessPattern() {
// immutable, shareable so:
return AccessPattern.CONSTANT;
}
@Override // since 2.9
public Object getEmptyValue(DeserializationContext ctxt) throws JsonMappingException {
return NO_STRINGS;
}
/**
* Contextualization is needed to see whether we can "inline" deserialization
* of String values, or if we have to use separate value deserializer.
*/
@Override
public JsonDeserializer createContextual(DeserializationContext ctxt, BeanProperty property)
throws JsonMappingException
{
JsonDeserializer deser = _elementDeserializer;
// May have a content converter
deser = findConvertingContentDeserializer(ctxt, property, deser);
JavaType type = ctxt.constructType(String.class);
if (deser == null) {
deser = ctxt.findContextualValueDeserializer(type, property);
} else { // if directly assigned, probably not yet contextual, so:
deser = ctxt.handleSecondaryContextualization(deser, property, type);
}
// One more thing: allow unwrapping?
Boolean unwrapSingle = findFormatFeature(ctxt, property, String[].class,
JsonFormat.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
NullValueProvider nuller = findContentNullProvider(ctxt, property, deser);
// Ok ok: if all we got is the default String deserializer, can just forget about it
if ((deser != null) && isDefaultDeserializer(deser)) {
deser = null;
}
if ((_elementDeserializer == deser)
&& (Objects.equals(_unwrapSingle, unwrapSingle))
&& (_nullProvider == nuller)) {
return this;
}
return new StringArrayDeserializer(deser, nuller, unwrapSingle);
}
@Override
public String[] deserialize(JsonParser p, DeserializationContext ctxt) throws IOException
{
// Ok: must point to START_ARRAY (or equivalent)
if (!p.isExpectedStartArrayToken()) {
return handleNonArray(p, ctxt);
}
if (_elementDeserializer != null) {
return _deserializeCustom(p, ctxt, null);
}
final ObjectBuffer buffer = ctxt.leaseObjectBuffer();
Object[] chunk = buffer.resetAndStart();
int ix = 0;
try {
while (true) {
String value = p.nextTextValue();
if (value == null) {
JsonToken t = p.currentToken();
if (t == JsonToken.END_ARRAY) {
break;
}
if (t == JsonToken.VALUE_NULL) {
if (_skipNullValues) {
continue;
}
value = (String) _nullProvider.getNullValue(ctxt);
} else {
value = _parseString(p, ctxt, _nullProvider);
}
}
if (ix >= chunk.length) {
chunk = buffer.appendCompletedChunk(chunk);
ix = 0;
}
chunk[ix++] = value;
}
} catch (Exception e) {
throw JsonMappingException.wrapWithPath(e, chunk, buffer.bufferedSize() + ix);
}
String[] result = buffer.completeAndClearBuffer(chunk, ix, String.class);
ctxt.returnObjectBuffer(buffer);
return result;
}
/**
* Offlined version used when we do not use the default deserialization method.
*/
protected final String[] _deserializeCustom(JsonParser p, DeserializationContext ctxt,
String[] old) throws IOException
{
final ObjectBuffer buffer = ctxt.leaseObjectBuffer();
int ix;
Object[] chunk;
if (old == null) {
ix = 0;
chunk = buffer.resetAndStart();
} else {
ix = old.length;
chunk = buffer.resetAndStart(old, ix);
}
final JsonDeserializer deser = _elementDeserializer;
try {
while (true) {
/* 30-Dec-2014, tatu: This may look odd, but let's actually call method
* that suggest we are expecting a String; this helps with some formats,
* notably XML. Note, however, that while we can get String, we can't
* assume that's what we use due to custom deserializer
*/
String value;
if (p.nextTextValue() == null) {
JsonToken t = p.currentToken();
if (t == JsonToken.END_ARRAY) {
break;
}
// Ok: no need to convert Strings, but must recognize nulls
if (t == JsonToken.VALUE_NULL) {
if (_skipNullValues) {
continue;
}
value = (String) _nullProvider.getNullValue(ctxt);
} else {
value = deser.deserialize(p, ctxt);
}
} else {
value = deser.deserialize(p, ctxt);
}
if (ix >= chunk.length) {
chunk = buffer.appendCompletedChunk(chunk);
ix = 0;
}
chunk[ix++] = value;
}
} catch (Exception e) {
// note: pass String.class, not String[].class, as we need element type for error info
throw JsonMappingException.wrapWithPath(e, String.class, ix);
}
String[] result = buffer.completeAndClearBuffer(chunk, ix, String.class);
ctxt.returnObjectBuffer(buffer);
return result;
}
@Override
public Object deserializeWithType(JsonParser p, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws IOException {
return typeDeserializer.deserializeTypedFromArray(p, ctxt);
}
@Override
public String[] deserialize(JsonParser p, DeserializationContext ctxt,
String[] intoValue) throws IOException
{
// Ok: must point to START_ARRAY (or equivalent)
if (!p.isExpectedStartArrayToken()) {
String[] arr = handleNonArray(p, ctxt);
if (arr == null) {
return intoValue;
}
final int offset = intoValue.length;
String[] result = new String[offset + arr.length];
System.arraycopy(intoValue, 0, result, 0, offset);
System.arraycopy(arr, 0, result, offset, arr.length);
return result;
}
if (_elementDeserializer != null) {
return _deserializeCustom(p, ctxt, intoValue);
}
final ObjectBuffer buffer = ctxt.leaseObjectBuffer();
int ix = intoValue.length;
Object[] chunk = buffer.resetAndStart(intoValue, ix);
try {
while (true) {
String value = p.nextTextValue();
if (value == null) {
JsonToken t = p.currentToken();
if (t == JsonToken.END_ARRAY) {
break;
}
if (t == JsonToken.VALUE_NULL) {
// 03-Feb-2017, tatu: Should we skip null here or not?
if (_skipNullValues) {
return NO_STRINGS;
}
value = (String) _nullProvider.getNullValue(ctxt);
} else {
value = _parseString(p, ctxt, _nullProvider);
}
}
if (ix >= chunk.length) {
chunk = buffer.appendCompletedChunk(chunk);
ix = 0;
}
chunk[ix++] = value;
}
} catch (Exception e) {
throw JsonMappingException.wrapWithPath(e, chunk, buffer.bufferedSize() + ix);
}
String[] result = buffer.completeAndClearBuffer(chunk, ix, String.class);
ctxt.returnObjectBuffer(buffer);
return result;
}
private final String[] handleNonArray(JsonParser p, DeserializationContext ctxt) throws IOException
{
// implicit arrays from single values?
boolean canWrap = (_unwrapSingle == Boolean.TRUE) ||
((_unwrapSingle == null) &&
ctxt.isEnabled(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY));
if (canWrap) {
String value;
if (p.hasToken(JsonToken.VALUE_NULL)) {
value = (String) _nullProvider.getNullValue(ctxt);
} else {
if (p.hasToken(JsonToken.VALUE_STRING)) {
String textValue = p.getText();
// https://github.com/FasterXML/jackson-dataformat-xml/issues/513
if (textValue.isEmpty()) {
final CoercionAction act = ctxt.findCoercionAction(logicalType(), handledType(),
CoercionInputShape.EmptyString);
if (act != CoercionAction.Fail) {
return (String[]) _deserializeFromEmptyString(p, ctxt, act, handledType(),
"empty String (\"\")");
}
} else if (_isBlank(textValue)) {
final CoercionAction act = ctxt.findCoercionFromBlankString(logicalType(), handledType(),
CoercionAction.Fail);
if (act != CoercionAction.Fail) {
return (String[]) _deserializeFromEmptyString(p, ctxt, act, handledType(),
"blank String (all whitespace)");
}
}
// if coercion failed, we can still add it to an array
}
value = _parseString(p, ctxt, _nullProvider);
}
return new String[] { value };
}
if (p.hasToken(JsonToken.VALUE_STRING)) {
return _deserializeFromString(p, ctxt);
}
return (String[]) ctxt.handleUnexpectedToken(_valueClass, p);
}
}