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

      • 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

      • nextToken

        public JsonToken nextToken()
                    throws java.io.IOException,
                           JsonParseException
        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
        JsonParseException

      • 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

      • getCurrentName

        public java.lang.String getCurrentName()
        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.
        Specified by:
        getCurrentName in class ParserMinimalBase

      • 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

      • getTokenLocation

        public JsonLocation getTokenLocation()
        Description copied from class: JsonParser
        Method that return the starting location of the current token; that is, position of the first character from input that starts the current token.
        Specified by:
        getTokenLocation in class JsonParser

      • getCurrentLocation

        public JsonLocation getCurrentLocation()
        Description copied from class: JsonParser
        Method that returns location of the last processed character; usually for error reporting purposes.
        Specified by:
        getCurrentLocation in class JsonParser

      • 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

      • getTextCharacters

        public char[] getTextCharacters()
                         throws java.io.IOException,
                                JsonParseException
        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
        Throws:
        java.io.IOException
        JsonParseException

      • 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

      • 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 JsonParseException will be thrown to indicate numeric overflow/underflow.

        Specified by:
        getDoubleValue in class JsonParser
        Throws:
        java.io.IOException

      • 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 JsonParseException will be thrown to indicate numeric overflow/underflow.

        Specified by:
        getFloatValue in class JsonParser
        Throws:
        java.io.IOException

      • 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 JsonParseException may be thrown to indicate numeric overflow/underflow.

        Specified by:
        getIntValue in class JsonParser
        Throws:
        java.io.IOException

      • 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 JsonParseException may be thrown to indicate numeric overflow/underflow.

        Specified by:
        getLongValue in class JsonParser
        Throws:
        java.io.IOException

      • 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
        Throws:
        java.io.IOException

      • 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

      • isNaN

        public boolean isNaN()
        Description copied from class: JsonParser
        Access for checking whether current token is a numeric value token, but one that is of "not-a-number" (NaN) variety (including both "NaN" AND positive/negative infinity!): not supported by all formats, but often supported for JsonToken.VALUE_NUMBER_FLOAT. NOTE: roughly equivalent to calling !Double.isFinite() on value you would get from calling JsonParser.getDoubleValue().
        Overrides:
        isNaN in class JsonParser

      • getBinaryValue

        public byte[] getBinaryValue​(Base64Variant b64variant)
                      throws java.io.IOException,
                             JsonParseException
        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
        JsonParseException