Package com.fasterxml.jackson.core.json.async

Class NonBlockingJsonParserBase

  • All Implemented Interfaces:
    Versioned, java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    NonBlockingUtf8JsonParserBase
    public abstract class NonBlockingJsonParserBase
extends JsonParserBase
    Intermediate base class for non-blocking JSON parsers.
    Since:
    2.9

    • Method Detail

      • canParseAsync

        public boolean canParseAsync()
        Description copied from class: JsonParser
        Method that can be called to determine if this parser instance uses non-blocking ("asynchronous") input access for decoding or not. Access mode is determined by earlier calls via JsonFactory; it may not be changed after construction.

        If non-blocking decoding is (@code true}, it is possible to call JsonParser.getNonBlockingInputFeeder() to obtain object to use for feeding input; otherwise (false returned) input is read by blocking

        Overrides:
        canParseAsync in class JsonParser
        Returns:
        True if this is a non-blocking ("asynchronous") parser

      • releaseBuffered

        public abstract int releaseBuffered​(java.io.OutputStream out)
                             throws java.io.IOException
        Description copied from class: JsonParser
        Method that can be called to push back any content that has been read but not consumed by the parser. This is usually done after reading all content of interest using parser. Content is released by writing it to given stream if possible; if underlying input is byte-based it can released, if not (char-based) it can not.
        Overrides:
        releaseBuffered in class JsonParser
        Parameters:
        out - OutputStream to which buffered, undecoded content is written to
        Returns:
        -1 if the underlying content source is not byte based (that is, input can not be sent to OutputStream; otherwise number of bytes released (0 if there was nothing to release)
        Throws:
        java.io.IOException - if write to stream threw exception

      • getInputSource

        public java.lang.Object getInputSource()
        Description copied from class: JsonParser
        Method that can be used to get access to object that is used to access input being parsed; this is usually either InputStream or Reader, depending on what parser was constructed with. Note that returned value may be null in some cases; including case where parser implementation does not want to exposed raw source to caller. In cases where input has been decorated, object returned here is the decorated version; this allows some level of interaction between users of parser and decorator object.

        In general use of this accessor should be considered as "last effort", i.e. only used if no other mechanism is applicable.

        Overrides:
        getInputSource in class JsonParser
        Returns:
        Input source this parser was configured with

      • hasTextCharacters

        public boolean hasTextCharacters()
        Description copied from class: JsonParser
        Method that can be used to determine whether calling of JsonParser.getTextCharacters() would be the most efficient way to access textual content for the event parser currently points to.

        Default implementation simply returns false since only actual implementation class has knowledge of its internal buffering state. Implementations are strongly encouraged to properly override this method, to allow efficient copying of content by other code.

        Overrides:
        hasTextCharacters in class ParserBase
        Returns:
        True if parser currently has character array that can be efficiently returned via JsonParser.getTextCharacters(); false means that it may or may not exist

      • currentLocation

        public JsonLocation currentLocation()
        Description copied from class: JsonParser
        Method that returns location of the last processed input unit (character or byte) from the input; usually for error reporting purposes.

        Note that the location is not guaranteed to be accurate (although most implementation will try their best): some implementations may only report specific boundary locations (start or end locations of tokens) and others only return JsonLocation.NA due to not having access to input location information (when delegating actual decoding work to other library)

        Specified by:
        currentLocation in class JsonParserBase
        Returns:
        Location of the last processed input unit (byte or character)

      • currentTokenLocation

        public JsonLocation currentTokenLocation()
        Description copied from class: JsonParser
        Method that return the starting location of the current (most recently returned) token; that is, the position of the first input unit (character or byte) from input that starts the current token.

        Note that the location is not guaranteed to be accurate (although most implementation will try their best): some implementations may only return JsonLocation.NA due to not having access to input location information (when delegating actual decoding work to other library)

        Specified by:
        currentTokenLocation in class JsonParserBase
        Returns:
        Starting location of the token parser currently points to

      • getText

        public java.lang.String getText()
                         throws java.io.IOException
        Method for accessing textual representation of the current event; if no current event (before first call to ParserMinimalBase.nextToken(), or after encountering end-of-input), returns null. Method can be called for any event.
        Specified by:
        getText in class ParserMinimalBase
        Returns:
        Textual value associated with the current token (one returned by JsonParser.nextToken() or other iteration methods)
        Throws:
        java.io.IOException - if there are general I/O or parse issues, including if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)

      • getText

        public int getText​(java.io.Writer writer)
            throws java.io.IOException
        Description copied from class: JsonParser
        Method to read the textual representation of the current token in chunks and pass it to the given Writer. Conceptually same as calling: 
          writer.write(parser.getText());
        but should typically be more efficient as longer content does need to be combined into a single String to return, and write can occur directly from intermediate buffers Jackson uses.
        Overrides:
        getText in class JsonParser
        Parameters:
        writer - Writer to write textual content to
        Returns:
        The number of characters written to the Writer
        Throws:
        java.io.IOException - for low-level read issues or writes using passed writer, or JsonParseException for decoding problems

      • getValueAsString

        public java.lang.String getValueAsString()
                                  throws java.io.IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a String. JSON Strings map naturally; scalar values get converted to their textual representation. If representation can not be converted to a String value (including structured types like Objects and Arrays and null token), default value of null will be returned; no exceptions are thrown.
        Overrides:
        getValueAsString in class ParserMinimalBase
        Returns:
        String value current token is converted to, if possible; null otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsString

        public java.lang.String getValueAsString​(java.lang.String defValue)
                                  throws java.io.IOException
        Description copied from class: JsonParser
        Method that will try to convert value of current token to a String. JSON Strings map naturally; scalar values get converted to their textual representation. If representation can not be converted to a String value (including structured types like Objects and Arrays and null token), specified default value will be returned; no exceptions are thrown.
        Overrides:
        getValueAsString in class ParserMinimalBase
        Parameters:
        defValue - Default value to return if conversion to String is not possible
        Returns:
        String value current token is converted to, if possible; def otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getTextCharacters

        public char[] getTextCharacters()
                         throws java.io.IOException
        Description copied from class: JsonParser
        Method similar to JsonParser.getText(), but that will return underlying (unmodifiable) character array that contains textual value, instead of constructing a String object to contain this information. Note, however, that:
        • Textual contents are not guaranteed to start at index 0 (rather, call JsonParser.getTextOffset()) to know the actual offset
        • Length of textual contents may be less than the length of returned buffer: call JsonParser.getTextLength() for actual length of returned content.

        Note that caller MUST NOT modify the returned character array in any way -- doing so may corrupt current parser state and render parser instance useless.

        The only reason to call this method (over JsonParser.getText()) is to avoid construction of a String object (which will make a copy of contents).

        Specified by:
        getTextCharacters in class ParserMinimalBase
        Returns:
        Buffer that contains the current textual value (but not necessarily at offset 0, and not necessarily until the end of buffer)
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems, including if the text is too large, see StreamReadConstraints.Builder.maxStringLength(int)

      • getBinaryValue

        public byte[] getBinaryValue​(Base64Variant b64variant)
                      throws java.io.IOException
        Description copied from class: JsonParser
        Method that can be used to read (and consume -- results may not be accessible using other methods after the call) base64-encoded binary data included in the current textual JSON value. It works similar to getting String value via JsonParser.getText() and decoding result (except for decoding part), but should be significantly more performant.

        Note that non-decoded textual contents of the current token are not guaranteed to be accessible after this method is called. Current implementation, for example, clears up textual content during decoding. Decoded binary content, however, will be retained until parser is advanced to the next event.

        Overrides:
        getBinaryValue in class ParserBase
        Parameters:
        b64variant - Expected variant of base64 encoded content (see Base64Variants for definitions of "standard" variants).
        Returns:
        Decoded binary data
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • readBinaryValue

        public int readBinaryValue​(Base64Variant b64variant,
                           java.io.OutputStream out)
                    throws java.io.IOException
        Description copied from class: JsonParser
        Similar to JsonParser.readBinaryValue(OutputStream) but allows explicitly specifying base64 variant to use.
        Overrides:
        readBinaryValue in class JsonParser
        Parameters:
        b64variant - base64 variant to use
        out - Output stream to use for passing decoded binary data
        Returns:
        Number of bytes that were decoded and written via OutputStream
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getEmbeddedObject

        public java.lang.Object getEmbeddedObject()
                                   throws java.io.IOException
        Description copied from class: JsonParser
        Accessor that can be called if (and only if) the current token is JsonToken.VALUE_EMBEDDED_OBJECT. For other token types, null is returned.

        Note: only some specialized parser implementations support embedding of objects (usually ones that are facades on top of non-streaming sources, such as object trees). One exception is access to binary content (whether via base64 encoding or not) which typically is accessible using this method, as well as JsonParser.getBinaryValue().

        Overrides:
        getEmbeddedObject in class JsonParser
        Returns:
        Embedded value (usually of "native" type supported by format) for the current token, if any; null otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems