Field Detail

• NOT_HANDLED

  public static final Object NOT_HANDLED

  Marker value returned by some handler methods to indicate that they could not handle problem and produce replacement value.

  Since:

  2.7

Constructor Detail

• DeserializationProblemHandler

  public DeserializationProblemHandler()

Method Detail

• handleUnknownProperty

  public boolean handleUnknownProperty(DeserializationContext ctxt,
                              JsonParser p,
                              JsonDeserializer<?> deserializer,
                              Object beanOrClass,
                              String propertyName)
                                throws IOException

  Method called when a JSON Object property with an unrecognized name is encountered. Content (supposedly) matching the property are accessible via parser that can be obtained from passed deserialization context. Handler can also choose to skip the content; if so, it MUST return true to indicate it did handle property successfully. Skipping is usually done like so:

    parser.skipChildren();
  

  Note: DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES) takes effect only after handler is called, and only if handler did not handle the problem.

  Parameters:

  beanOrClass - Either bean instance being deserialized (if one has been instantiated so far); or Class that indicates type that will be instantiated (if no instantiation done yet: for example when bean uses non-default constructors)

  p - Parser to use for handling problematic content

  Returns:

  True if the problem is resolved (and content available used or skipped); false if the handler did not anything and the problem is unresolved. Note that in latter case caller will either throw an exception or explicitly skip the content, depending on configuration.

  Throws:

  IOException

• handleWeirdKey

  public Object handleWeirdKey(DeserializationContext ctxt,
                      Class<?> rawKeyType,
                      String keyValue,
                      String failureMsg)
                        throws IOException

  Method called when a property name from input can not be converted to a non-Java-String key type (passed as rawKeyType) due to format problem. Handler may choose to do one of 3 things:

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Return actual key value to use as replacement, and continue processing.

  Parameters:

  failureMsg - Message that will be used by caller (by calling DeserializationContext.weirdKeyException(Class, String, String)) to indicate type of failure unless handler produces key to use

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use as key (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleWeirdStringValue

  public Object handleWeirdStringValue(DeserializationContext ctxt,
                              Class<?> targetType,
                              String valueToConvert,
                              String failureMsg)
                                throws IOException

  Method called when a String value can not be converted to a non-String value type due to specific problem (as opposed to String values never being usable). Handler may choose to do one of 3 things:

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Return actual converted value (of type targetType) to use as replacement, and continue processing.

  Parameters:

  failureMsg - Message that will be used by caller (by calling DeserializationContext.weirdNumberException(java.lang.Number, java.lang.Class<?>, java.lang.String)) to indicate type of failure unless handler produces key to use

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use as key (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleWeirdNumberValue

  public Object handleWeirdNumberValue(DeserializationContext ctxt,
                              Class<?> targetType,
                              Number valueToConvert,
                              String failureMsg)
                                throws IOException

  Method called when a numeric value (integral or floating-point from input can not be converted to a non-numeric value type due to specific problem (as opposed to numeric values never being usable). Handler may choose to do one of 3 things:

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Return actual converted value (of type targetType) to use as replacement, and continue processing.

  Parameters:

  failureMsg - Message that will be used by caller (by calling DeserializationContext.weirdNumberException(java.lang.Number, java.lang.Class<?>, java.lang.String)) to indicate type of failure unless handler produces key to use

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use as key (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleUnexpectedToken

  public Object handleUnexpectedToken(DeserializationContext ctxt,
                             Class<?> targetType,
                             JsonToken t,
                             JsonParser p,
                             String failureMsg)
                               throws IOException

  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 JsonToken.START_ARRAY instead of JsonToken.VALUE_NUMBER_INT or JsonToken.VALUE_NUMBER_FLOAT.

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Handle content to match (by consuming or skipping it), and return actual instantiated value (of type targetType) to use as replacement; value may be `null` as well as expected target type.

  Parameters:

  failureMsg - Message that will be used by caller to indicate type of failure unless handler produces value to use

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleInstantiationProblem

  public Object handleInstantiationProblem(DeserializationContext ctxt,
                                  Class<?> instClass,
                                  Object argument,
                                  Throwable t)
                                    throws IOException

  Method called when instance creation for a type fails due to an exception. Handler may choose to do one of following things:

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Return actual instantiated value (of type targetType) to use as replacement, and continue processing.
  • Return null to use null as value but not to try further processing (in cases where properties would otherwise be bound)

  Parameters:

  instClass - Type that was to be instantiated

  argument - (optional) Additional argument that was passed to creator, if any

  t - Exception that caused instantiation failure

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleMissingInstantiator

  public Object handleMissingInstantiator(DeserializationContext ctxt,
                                 Class<?> instClass,
                                 JsonParser p,
                                 String msg)
                                   throws IOException

  Method called when instance creation for a type fails due to lack of an instantiator. Method is called before actual deserialization from input is attempted, so handler may do one of following things:

  • Indicate it does not know what to do by returning NOT_HANDLED
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Handle content to match (by consuming or skipping it), and return actual instantiated value (of type targetType) to use as replacement; value may be `null` as well as expected target type.

  Parameters:

  instClass - Type that was to be instantiated

  p - Parser to use for accessing content that needs handling, to either use it or skip it (latter with JsonParser.skipChildren().

  Returns:

  Either NOT_HANDLED to indicate that handler does not know what to do (and exception may be thrown), or value to use (possibly null

  Throws:

  IOException

  Since:

  2.8

• handleUnknownTypeId

  public JavaType handleUnknownTypeId(DeserializationContext ctxt,
                             JavaType baseType,
                             String subTypeId,
                             TypeIdResolver idResolver,
                             String failureMsg)
                               throws IOException

  Handler method called if resolution of type id from given String failed to produce a subtype; usually because logical id is not mapped to actual implementation class. Handler may choose to do one of following things:

  • Indicate it does not know what to do by returning `null`
  • Indicate that nothing should be deserialized, by return `Void.class`
  • Throw a IOException to indicate specific fail message (instead of standard exception caller would throw
  • Return actual resolved type to use for type id.

  Parameters:

  ctxt - Deserialization context to use for accessing information or constructing exception to throw

  baseType - Base type to use for resolving subtype id

  subTypeId - Subtype id that failed to resolve

  failureMsg - Informational message that would be thrown as part of exception, if resolution still fails

  Returns:

  Actual type to use, if resolved; `null` if handler does not know what to do; or `Void.class` to indicate that nothing should be deserialized for type with the id (which caller may choose to do... or not)

  Throws:

  IOException

  Since:

  2.8