Package com.fasterxml.jackson.databind.ext

Class NioPathDeserializer

    • Field Detail

      • DEFAULT_ALLOWED_SCHEMES

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

      • _allowedSchemes

        protected final java.util.Collection<java.lang.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 Detail

      • NioPathDeserializer

        public NioPathDeserializer()

      • NioPathDeserializer

        public NioPathDeserializer​(java.util.Collection<java.lang.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 Detail

      • deserialize

        public java.nio.file.Path deserialize​(com.fasterxml.jackson.core.JsonParser p,
                                      DeserializationContext ctxt)
                               throws java.io.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<java.nio.file.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:
        java.io.IOException

      • _isSchemeAllowed

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