Package com.fasterxml.jackson.databind.node

Class TreeTraversingParser

  • All Implemented Interfaces:
    Versioned, java.io.Closeable, java.lang.AutoCloseable
    public class TreeTraversingParser
extends ParserMinimalBase
    Facade over JsonNode that implements JsonParser to allow accessing contents of JSON tree in alternate form (stream of tokens). Useful when a streaming source is expected by code, such as data binding functionality.

    • Constructor Detail

      • TreeTraversingParser

        public TreeTraversingParser​(JsonNode n)

    • Method Detail

      • version

        public Version version()
        Description copied from class: JsonParser
        Accessor for getting version of the core package, given a parser instance. Left for sub-classes to implement.
        Specified by:
        version in interface Versioned
        Specified by:
        version in class JsonParser
        Returns:
        Version of this generator (derived from version declared for jackson-core jar that contains the class

      • getReadCapabilities

        public JacksonFeatureSet<StreamReadCapability> getReadCapabilities()
        Description copied from class: JsonParser
        Accessor for getting metadata on capabilities of this parser, based on underlying data format being read (directly or indirectly).
        Overrides:
        getReadCapabilities in class JsonParser
        Returns:
        Set of read capabilities for content to read via this parser

      • close

        public void close()
           throws java.io.IOException
        Description copied from class: JsonParser
        Closes the parser so that no further iteration or data access can be made; will also close the underlying input source if parser either owns the input source, or feature JsonParser.Feature.AUTO_CLOSE_SOURCE is enabled. Whether parser owns the input source depends on factory method that was used to construct instance (so check JsonFactory for details, but the general idea is that if caller passes in closable resource (such as InputStream or Reader) parser does NOT own the source; but if it passes a reference (such as File or URL and creates stream or reader it does own them.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Specified by:
        close in class ParserMinimalBase
        Throws:
        java.io.IOException - if there is either an underlying I/O problem

      • nextToken

        public JsonToken nextToken()
                    throws java.io.IOException
        Description copied from class: JsonParser
        Main iteration method, which will advance stream enough to determine type of the next token, if any. If none remaining (stream has no content other than possible white space before ending), null will be returned.
        Specified by:
        nextToken in class ParserMinimalBase
        Returns:
        Next token from the stream, if any found, or null to indicate end-of-input
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • isClosed

        public boolean isClosed()
        Description copied from class: JsonParser
        Method that can be called to determine whether this parser is closed or not. If it is closed, no new tokens can be retrieved by calling JsonParser.nextToken() (and the underlying stream may be closed). Closing may be due to an explicit call to JsonParser.close() or because parser has encountered end of input.
        Specified by:
        isClosed in class ParserMinimalBase
        Returns:
        True if this parser instance has been closed

      • currentName

        public java.lang.String currentName()
        Description copied from class: JsonParser
        Method that can be called to get the name associated with the current token: for JsonToken.FIELD_NAMEs it will be the same as what JsonParser.getText() returns; for field values it will be preceding field name; and for others (array values, root-level values) null.
        Overrides:
        currentName in class JsonParser
        Returns:
        Name of the current field in the parsing context

      • overrideCurrentName

        public void overrideCurrentName​(java.lang.String name)
        Description copied from class: JsonParser
        Method that can be used to change what is considered to be the current (field) name. May be needed to support non-JSON data formats or unusual binding conventions; not needed for typical processing.

        Note that use of this method should only be done as sort of last resort, as it is a work-around for regular operation.

        Specified by:
        overrideCurrentName in class ParserMinimalBase
        Parameters:
        name - Name to use as the current name; may be null.

      • getParsingContext

        public JsonStreamContext getParsingContext()
        Description copied from class: JsonParser
        Method that can be used to access current parsing context reader is in. There are 3 different types: root, array and object contexts, with slightly different available information. Contexts are hierarchically nested, and can be used for example for figuring out part of the input document that correspond to specific array or object (for highlighting purposes, or error reporting). Contexts can also be used for simple xpath-like matching of input, if so desired.
        Specified by:
        getParsingContext in class ParserMinimalBase
        Returns:
        Stream input context (JsonStreamContext) associated with this parser

      • 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)

        Overrides:
        currentLocation in class JsonParser
        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)

        Overrides:
        currentTokenLocation in class JsonParser
        Returns:
        Starting location of the token parser currently points to

      • getText

        public java.lang.String getText()
        Description copied from class: JsonParser
        Method for accessing textual representation of the current token; if no current token (before first call to JsonParser.nextToken(), or after encountering end-of-input), returns null. Method can be called for any token type.
        Specified by:
        getText in class ParserMinimalBase
        Returns:
        Textual value associated with the current token (one returned by JsonParser.nextToken() or other iteration methods)

      • 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)

      • 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.

        Specified by:
        hasTextCharacters in class ParserMinimalBase
        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

      • getBigIntegerValue

        public java.math.BigInteger getBigIntegerValue()
                                        throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can not be used as a Java long primitive type due to its magnitude. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDecimalValue() and then constructing a BigInteger from that value.
        Specified by:
        getBigIntegerValue in class JsonParser
        Returns:
        Current number value as BigInteger (if numeric token); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getDecimalValue

        public java.math.BigDecimal getDecimalValue()
                                     throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT or JsonToken.VALUE_NUMBER_INT. No under/overflow exceptions are ever thrown.
        Specified by:
        getDecimalValue in class JsonParser
        Returns:
        Current number value as BigDecimal (if numeric token); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getDoubleValue

        public double getDoubleValue()
                      throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java double primitive type. It can also be called for JsonToken.VALUE_NUMBER_INT; if so, it is equivalent to calling JsonParser.getLongValue() and then casting; except for possible overflow/underflow exception.

        Note: if the value falls outside of range of Java double, a InputCoercionException will be thrown to indicate numeric overflow/underflow.

        Specified by:
        getDoubleValue in class JsonParser
        Returns:
        Current number value as double (if numeric token within Java double range); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getFloatValue

        public float getFloatValue()
                    throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_FLOAT and it can be expressed as a Java float primitive type. It can also be called for JsonToken.VALUE_NUMBER_INT; if so, it is equivalent to calling JsonParser.getLongValue() and then casting; except for possible overflow/underflow exception.

        Note: if the value falls outside of range of Java float, a InputCoercionException will be thrown to indicate numeric overflow/underflow.

        Specified by:
        getFloatValue in class JsonParser
        Returns:
        Current number value as float (if numeric token within Java float range); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getIntValue

        public int getIntValue()
                throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a value of Java int primitive type. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDoubleValue() and then casting; except for possible overflow/underflow exception.

        Note: if the resulting integer value falls outside range of Java int, a InputCoercionException may be thrown to indicate numeric overflow/underflow.

        Specified by:
        getIntValue in class JsonParser
        Returns:
        Current number value as int (if numeric token within Java 32-bit signed int range); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getLongValue

        public long getLongValue()
                  throws java.io.IOException
        Description copied from class: JsonParser
        Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it can be expressed as a Java long primitive type. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling JsonParser.getDoubleValue() and then casting to int; except for possible overflow/underflow exception.

        Note: if the token is an integer, but its value falls outside of range of Java long, a InputCoercionException may be thrown to indicate numeric overflow/underflow.

        Specified by:
        getLongValue in class JsonParser
        Returns:
        Current number value as long (if numeric token within Java 32-bit signed long range); otherwise exception thrown
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getNumberValue

        public java.lang.Number getNumberValue()
                                throws java.io.IOException
        Description copied from class: JsonParser
        Generic number value accessor method that will work for all kinds of numeric values. It will return the optimal (simplest/smallest possible) wrapper object that can express the numeric value just parsed.
        Specified by:
        getNumberValue in class JsonParser
        Returns:
        Numeric value of the current token in its most optimal representation
        Throws:
        java.io.IOException - Problem with access: JsonParseException if the current token is not numeric, or if decoding of the value fails (invalid format for numbers); plain IOException if underlying content read fails (possible if values are extracted lazily)

      • getEmbeddedObject

        public java.lang.Object getEmbeddedObject()
        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

      • isNaN

        public boolean isNaN()
        Description copied from class: JsonParser
        Accessor for checking whether current token is a special "not-a-number" (NaN) token (including both "NaN" AND positive/negative infinity!). These values are not supported by all formats: JSON, for example, only supports them if JsonReadFeature.ALLOW_NON_NUMERIC_NUMBERS is enabled.

        NOTE: in case where numeric value is outside range of requested type -- most notably Float or Double -- and decoding results effectively in a NaN value, this method DOES NOT return true: only explicit incoming markers do. This is because value could still be accessed as a valid BigDecimal.

        Overrides:
        isNaN in class JsonParser
        Returns:
        True if the current token is reported as JsonToken.VALUE_NUMBER_FLOAT and represents a "Not a Number" value; false for other tokens and regular floating-point numbers.

      • 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.

        Specified by:
        getBinaryValue in class ParserMinimalBase
        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