Class NioPathDeserializer

java.lang.Object
com.fasterxml.jackson.databind.JsonDeserializer<Path>
com.fasterxml.jackson.databind.deser.std.StdDeserializer<Path>
com.fasterxml.jackson.databind.deser.std.StdScalarDeserializer<Path>
com.fasterxml.jackson.databind.ext.NioPathDeserializer
All Implemented Interfaces:
NullValueProvider, ValueInstantiator.Gettable, Serializable
public class NioPathDeserializer extends StdScalarDeserializer<Path>
Since:
2.8
See Also:

  • Field Details

    • DEFAULT_ALLOWED_SCHEMES

      public static final Collection<String> DEFAULT_ALLOWED_SCHEMES
      URI schemes accepted unless overridden: only "file", scheme of the default FileSystem.
      Since:
      2.18.10

    • _allowedSchemes

      protected final Collection<String> _allowedSchemes
      URI schemes accepted by this instance; values with no scheme at all are always accepted (and read as local file system paths).
      Since:
      2.18.10

  • Constructor Details

    • NioPathDeserializer

      public NioPathDeserializer()

    • NioPathDeserializer

      public NioPathDeserializer(Collection<String> allowedSchemes)
      Constructor for specifying URI schemes to accept: matching is done case-insensitively, same as by java.nio.file.Paths.get(URI).

      NOTE: for allowed schemes that have no provider installed for the system class loader, look up is also attempted using this thread's context class loader (see [databind#2120]); this is never done for schemes that are not allowed.

      Parameters:
      allowedSchemes - URI schemes to accept; must not be null (but may be empty to only accept scheme-less values)
      Since:
      2.18.10

  • Method Details

    • deserialize

      public Path deserialize(com.fasterxml.jackson.core.JsonParser p, DeserializationContext ctxt) throws IOException
      Description copied from class: JsonDeserializer
      Method that can be called to ask implementation to deserialize JSON content into the value type this serializer handles. Returned instance is to be constructed by method itself.

      Pre-condition for this method is that the parser points to the first event that is part of value to deserializer (and which is never JSON 'null' literal, more on this below): for simple types it may be the only value; and for structured types the Object start marker or a FIELD_NAME.

      The two possible input conditions for structured types result from polymorphism via fields. In the ordinary case, Jackson calls this method when it has encountered an OBJECT_START, and the method implementation must advance to the next token to see the first field name. If the application configures polymorphism via a field, then the object looks like the following. 

            {
          "@class": "class name",
          ...
      }
      Jackson consumes the two tokens (the @class field name and its value) in order to learn the class and select the deserializer. Thus, the stream is pointing to the FIELD_NAME for the first field after the @class. Thus, if you want your method to work correctly both with and without polymorphism, you must begin your method with: 
             if (p.currentToken() == JsonToken.START_OBJECT) {
         p.nextToken();
       }
      This results in the stream pointing to the field name, so that the two conditions align.

      Post-condition is that the parser will point to the last event that is part of deserialized value (or in case deserialization fails, event that was not recognized or usable, which may be the same event as the one it pointed to upon call).

      Handling null values (JsonToken.VALUE_NULL)
      : Note that this method is never called for the JSON null literal to avoid every deserializer from having to handle null values. Instead, the JsonDeserializer.getNullValue(DeserializationContext) method is called to produce a null value. To influence null handling, custom deserializers should override JsonDeserializer.getNullValue(DeserializationContext) and usually also JsonDeserializer.getNullAccessPattern().

      Specified by:
      deserialize in class JsonDeserializer<Path>
      Parameters:
      p - Parser used for reading JSON content
      ctxt - Context that can be used to access information about this deserialization activity.
      Returns:
      Deserialized value
      Throws:
      IOException

    • _isSchemeAllowed

      protected boolean _isSchemeAllowed(String scheme)
      Helper method for checking whether given non-null URI scheme is one of allowed ones; comparison is case-insensitive, as per URI specification (and as done by java.nio.file.Paths.get(URI)).
      Since:
      2.18.10

    • _allowedSchemesDesc

      protected String _allowedSchemesDesc()
      Helper method for constructing description of allowed schemes for inclusion in exception message, like ["file", "jar", "https"].
      Since:
      2.18.10