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More for #1207: now add `DeserializationContext.handleUnexpectedToken…
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…()` (and handler method in `DeserializationProblemHandler`), for the common failure mode of getting JSON token of unexpected type
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@cowtowncoder
cowtowncoder committed May 22, 2016
1 parent 6824544 commit 851092c
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Showing 26 changed files with 303 additions and 304 deletions.
147 changes: 96 additions & 51 deletions src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java
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Original file line number Diff line number Diff line change
Expand Up @@ -770,7 +770,7 @@ public <T> T readValue(JsonParser p, Class<T> type) throws IOException {
public <T> T readValue(JsonParser p, JavaType type) throws IOException {
JsonDeserializer<Object> deser = findRootValueDeserializer(type);
if (deser == null) {
throw mappingException("Could not find JsonDeserializer for type %s", type);
throw mappingException("Could not find JsonDeserializer for type "+type);
}
return (T) deser.deserialize(p, this);
}
Expand All @@ -795,8 +795,9 @@ public <T> T readPropertyValue(JsonParser p, BeanProperty prop, JavaType type) t
JsonDeserializer<Object> deser = findContextualValueDeserializer(type, prop);
if (deser == null) {
String propName = (prop == null) ? "NULL" : ("'"+prop.getName()+"'");
throw mappingException("Could not find JsonDeserializer for type %s (via property %s)",
type, propName);
throw mappingException(String.format(
"Could not find JsonDeserializer for type %s (via property %s)",
type, propName));
}
return (T) deser.deserialize(p, this);
}
Expand Down Expand Up @@ -1059,6 +1060,71 @@ public Object handleInstantiationProblem(Class<?> instClass, Object argument,
throw instantiationException(instClass, t);
}

/**
* Method that deserializers should call if the first token of the value to
* deserialize is of unexpected type (that is, type of token that deserializer
* can not handle). This could occur, for example, if a Number deserializer
* encounter {@link JsonToken#START_ARRAY} instead of
* {@link JsonToken#VALUE_NUMBER_INT} or {@link JsonToken#VALUE_NUMBER_FLOAT}.
*
* @param instClass Type that was to be instantiated
* @param p Parser that points to the JSON value to decode
*
* @return Object that should be constructed, if any; has to be of type <code>instClass</code>
*
* @since 2.8
*/
public Object handleUnexpectedToken(Class<?> instClass, JsonParser p)
throws IOException
{
return handleUnexpectedToken(instClass, p.getCurrentToken(), p, null);
}

/**
* Method that deserializers should call if the first token of the value to
* deserialize is of unexpected type (that is, type of token that deserializer
* can not handle). This could occur, for example, if a Number deserializer
* encounter {@link JsonToken#START_ARRAY} instead of
* {@link JsonToken#VALUE_NUMBER_INT} or {@link JsonToken#VALUE_NUMBER_FLOAT}.
*
* @param instClass Type that was to be instantiated
* @param p Parser that points to the JSON value to decode
*
* @return Object that should be constructed, if any; has to be of type <code>instClass</code>
*
* @since 2.8
*/
public Object handleUnexpectedToken(Class<?> instClass, JsonToken t,
JsonParser p,
String msg, Object... msgArgs)
throws IOException
{
if (msgArgs.length > 0) {
msg = String.format(msg, msgArgs);
}
/*
LinkedNode<DeserializationProblemHandler> h = _config.getProblemHandlers();
while (h != null) {
Object instance = h.value().handleUnexpectedToken(this,
instClass, t, p, msg);
if (instance != DeserializationProblemHandler.NOT_HANDLED) {
if ((instance == null) || instClass.isInstance(instance)) {
return instance;
}
throw mappingException(String.format(
"DeserializationProblemHandler.handleUnexpectedToken() for type %s returned value of type %s",
instClass, instance.getClass()));
}
h = h.next();
}
*/
if (msg == null) {
msg = String.format("Can not deserialize instance of %s out of %s token",
_calcName(instClass), t);
}
throw mappingException(msg);
}

/**
* Method that deserializers should call if they encounter a type id
* (for polymorphic deserialization) that can not be resolved to an
Expand Down Expand Up @@ -1123,7 +1189,7 @@ public void reportWrongTokenException(JsonParser p,
JsonToken expToken, String msg, Object... msgArgs)
throws JsonMappingException
{
if (msgArgs.length > 0) {
if ((msg != null) && (msgArgs.length > 0)) {
msg = String.format(msg, msgArgs);
}
throw wrongTokenException(p, expToken, msg);
Expand Down Expand Up @@ -1166,50 +1232,18 @@ public void reportMappingException(String msg, Object... msgArgs)
throw mappingException(msg);
}

/**
* @since 2.8
*/
public void reportMappingException(Class<?> targetClass, JsonToken t) throws JsonMappingException {
throw mappingException(targetClass, t);
}

/**
* @since 2.8
*/
public void reportMappingException(Class<?> targetClass) throws JsonMappingException {
throw mappingException(targetClass);
}

/*
/**********************************************************
/* Methods for constructing exceptions, "untyped"
/**********************************************************
*/

/**
* Helper method for constructing generic mapping exception for specified type
*
* @deprecated Since 2.8 use {@link #reportMappingException(Class)} instead
*/
@Deprecated
public JsonMappingException mappingException(Class<?> targetClass) {
return mappingException(targetClass, _parser.getCurrentToken());
}

/**
* @deprecated Since 2.8 use {@link #reportMappingException(Class, JsonToken)} instead
*/
@Deprecated
public JsonMappingException mappingException(Class<?> targetClass, JsonToken token) {
return JsonMappingException.from(_parser,
String.format("Can not deserialize instance of %s out of %s token",
_calcName(targetClass), token));
}

/**
* @deprecated Since 2.8 use {@link #reportMappingException(String, Object...)} instead
* Helper method for constructing generic mapping exception with specified
* message and current location information
*
* @since 2.6
*/
@Deprecated
public JsonMappingException mappingException(String message) {
return JsonMappingException.from(getParser(), message);
}
Expand All @@ -1219,17 +1253,34 @@ public JsonMappingException mappingException(String message) {
* message and current location information
*
* @since 2.6
*
* @deprecated Since 2.8 use {@link #reportMappingException(String, Object...)} instead
*/
@Deprecated
public JsonMappingException mappingException(String msgTemplate, Object... args) {
if (args != null && args.length > 0) {
msgTemplate = String.format(msgTemplate, args);
}
return JsonMappingException.from(getParser(), msgTemplate);
}

/**
* Helper method for constructing generic mapping exception for specified type
*
* @deprecated Since 2.8 use {@link #handleUnexpectedToken(Class, JsonParser)} instead
*/
@Deprecated
public JsonMappingException mappingException(Class<?> targetClass) {
return mappingException(targetClass, _parser.getCurrentToken());
}

/**
* @deprecated Since 2.8 use {@link #handleUnexpectedToken(Class, JsonParser)} instead
*/
@Deprecated
public JsonMappingException mappingException(Class<?> targetClass, JsonToken token) {
return JsonMappingException.from(_parser,
String.format("Can not deserialize instance of %s out of %s token",
_calcName(targetClass), token));
}

/*
/**********************************************************
/* Methods for constructing semantic exceptions; usually not
Expand Down Expand Up @@ -1359,7 +1410,7 @@ public JsonMappingException unknownTypeIdException(JavaType baseType, String typ

/*
/**********************************************************
/* Methods for constructing semantic exceptions
/* Deprecated exception factory methods
/**********************************************************
*/

Expand Down Expand Up @@ -1393,7 +1444,7 @@ public JsonMappingException endOfInputException(Class<?> instClass) {

/*
/**********************************************************
/* Overridable internal methods
/* Other internal methods
/**********************************************************
*/

Expand All @@ -1415,12 +1466,6 @@ protected DateFormat getDateFormat()
protected String determineClassName(Object instance) {
return ClassUtil.getClassDescription(instance);
}

/*
/**********************************************************
/* Other internal methods
/**********************************************************
*/

protected String _calcName(Class<?> cls) {
if (cls.isArray()) {
Expand Down
6 changes: 2 additions & 4 deletions src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -185,8 +185,7 @@ protected final Object _deserializeOther(JsonParser p, DeserializationContext ct
return deserializeFromObject(p, ctxt);
default:
}
ctxt.reportMappingException(handledType());
return null;
return ctxt.handleUnexpectedToken(handledType(), p);
}

@Deprecated // since 2.8; remove unless getting used
Expand Down Expand Up @@ -514,8 +513,7 @@ protected Object deserializeFromNull(JsonParser p, DeserializationContext ctxt)
p2.close();
return ob;
}
ctxt.reportMappingException(handledType());
return null;
return ctxt.handleUnexpectedToken(handledType(), p);
}

/*
Expand Down
7 changes: 3 additions & 4 deletions src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializerBase.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1353,11 +1353,10 @@ public Object deserializeFromArray(JsonParser p, DeserializationContext ctxt) th
if (t == JsonToken.END_ARRAY) {
return null;
}
ctxt.reportMappingException(handledType(), JsonToken.START_ARRAY);
return null;
return ctxt.handleUnexpectedToken(handledType(),
JsonToken.START_ARRAY, p, null);
}
ctxt.reportMappingException(handledType());
return null;
return ctxt.handleUnexpectedToken(handledType(), p);
}

public Object deserializeFromEmbedded(JsonParser p, DeserializationContext ctxt)
Expand Down
47 changes: 24 additions & 23 deletions src/main/java/com/fasterxml/jackson/databind/deser/BuilderBasedDeserializer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -143,7 +143,7 @@ protected final Object finishBuild(DeserializationContext ctxt, Object builder)
*/
@Override
public final Object deserialize(JsonParser p, DeserializationContext ctxt)
throws IOException, JsonProcessingException
throws IOException
{
JsonToken t = p.getCurrentToken();

Expand All @@ -157,28 +157,29 @@ public final Object deserialize(JsonParser p, DeserializationContext ctxt)
return finishBuild(ctxt, builder);
}
// and then others, generally requiring use of @JsonCreator
switch (t) {
case VALUE_STRING:
return finishBuild(ctxt, deserializeFromString(p, ctxt));
case VALUE_NUMBER_INT:
return finishBuild(ctxt, deserializeFromNumber(p, ctxt));
case VALUE_NUMBER_FLOAT:
return finishBuild(ctxt, deserializeFromDouble(p, ctxt));
case VALUE_EMBEDDED_OBJECT:
return p.getEmbeddedObject();
case VALUE_TRUE:
case VALUE_FALSE:
return finishBuild(ctxt, deserializeFromBoolean(p, ctxt));
case START_ARRAY:
// these only work if there's a (delegating) creator...
return finishBuild(ctxt, deserializeFromArray(p, ctxt));
case FIELD_NAME:
case END_OBJECT:
return finishBuild(ctxt, deserializeFromObject(p, ctxt));
default:
ctxt.reportMappingException(handledType());
return null;
if (t != null) {
switch (t) {
case VALUE_STRING:
return finishBuild(ctxt, deserializeFromString(p, ctxt));
case VALUE_NUMBER_INT:
return finishBuild(ctxt, deserializeFromNumber(p, ctxt));
case VALUE_NUMBER_FLOAT:
return finishBuild(ctxt, deserializeFromDouble(p, ctxt));
case VALUE_EMBEDDED_OBJECT:
return p.getEmbeddedObject();
case VALUE_TRUE:
case VALUE_FALSE:
return finishBuild(ctxt, deserializeFromBoolean(p, ctxt));
case START_ARRAY:
// these only work if there's a (delegating) creator...
return finishBuild(ctxt, deserializeFromArray(p, ctxt));
case FIELD_NAME:
case END_OBJECT:
return finishBuild(ctxt, deserializeFromObject(p, ctxt));
default:
}
}
return ctxt.handleUnexpectedToken(handledType(), p);
}

/**
Expand All @@ -189,7 +190,7 @@ public final Object deserialize(JsonParser p, DeserializationContext ctxt)
@Override
public Object deserialize(JsonParser p, DeserializationContext ctxt,
Object builder)
throws IOException, JsonProcessingException
throws IOException
{
/* Important: we call separate method which does NOT call
* 'finishBuild()', to avoid problems with recursion
Expand Down
40 changes: 38 additions & 2 deletions src/main/java/com/fasterxml/jackson/databind/deser/DeserializationProblemHandler.java
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
import java.io.IOException;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationConfig;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JavaType;
Expand Down Expand Up @@ -172,6 +173,41 @@ public Object handleWeirdNumberValue(DeserializationContext ctxt,
return NOT_HANDLED;
}

/**
* Method that deserializers should call if the first token of the value to
* deserialize is of unexpected type (that is, type of token that deserializer
* can not handle). This could occur, for example, if a Number deserializer
* encounter {@link JsonToken#START_ARRAY} instead of
* {@link JsonToken#VALUE_NUMBER_INT} or {@link JsonToken#VALUE_NUMBER_FLOAT}.
*<ul>
* <li>Indicate it does not know what to do by returning {@link #NOT_HANDLED}
* </li>
* <li>Throw a {@link IOException} to indicate specific fail message (instead of
* standard exception caller would throw
* </li>
* <li>Handle content to match (by consuming or skipping it), and return actual
* instantiated value (of type <code>targetType</code>) to use as replacement;
* value may be `null` as well as expected target type.
* </li>
* </ul>
*
* @param failureMsg Message that will be used by caller
* to indicate type of failure unless handler produces value to use
*
* @return Either {@link #NOT_HANDLED} to indicate that handler does not know
* what to do (and exception may be thrown), or value to use (possibly
* <code>null</code>
*
* @since 2.8
*/
public Object handleUnexpectedToken(DeserializationContext ctxt,
Class<?> targetType, JsonToken t, JsonParser p,
String failureMsg)
throws IOException
{
return NOT_HANDLED;
}

/**
* Method called when instance creation for a type fails due to an exception.
* Handler may choose to do one of following things:
Expand All @@ -194,7 +230,7 @@ public Object handleWeirdNumberValue(DeserializationContext ctxt,
* @param t Exception that caused instantiation failure
*
* @return Either {@link #NOT_HANDLED} to indicate that handler does not know
* what to do (and exception may be thrown), or value to use as key (possibly
* what to do (and exception may be thrown), or value to use (possibly
* <code>null</code>
*
* @since 2.8
Expand Down Expand Up @@ -227,7 +263,7 @@ public Object handleInstantiationProblem(DeserializationContext ctxt,
* use it or skip it (latter with {@link JsonParser#skipChildren()}.
*
* @return Either {@link #NOT_HANDLED} to indicate that handler does not know
* what to do (and exception may be thrown), or value to use as key (possibly
* what to do (and exception may be thrown), or value to use (possibly
* <code>null</code>
*
* @since 2.8
Expand Down
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