Module tools.jackson.core
Package tools.jackson.core

Class JsonParser

java.lang.Object
tools.jackson.core.JsonParser
All Implemented Interfaces:
Closeable, AutoCloseable, Versioned
Direct Known Subclasses:
JsonParserDelegate, ParserMinimalBase
public abstract class JsonParser extends Object implements Closeable, Versioned
Base class that defines public API for reading JSON content. Instances are created using factory methods of a JsonFactory instance.
Author:
Tatu Saloranta

  • Field Details

  • Constructor Details

    • JsonParser

      protected JsonParser()

  • Method Details

    • version

      public abstract Version version()
      Accessor for getting version of the core package, given a parser instance. Left for sub-classes to implement.
      Specified by:
      version in interface Versioned
      Returns:
      Version of the component

    • streamReadContext

      public abstract TokenStreamContext streamReadContext()
      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.

      NOTE: method was called getParsingContext() in Jackson 2.x

      Returns:
      Stream output context (TokenStreamContext) associated with this parser

    • objectReadContext

      public abstract ObjectReadContext objectReadContext()
      Accessor for context object provided by higher level data-binding functionality (or, in some cases, simple placeholder of the same) that allows some level of interaction including ability to trigger deserialization of Object values through generator instance.

      Context object is used by parser to implement some methods, like readValueAs(...)

      Returns:
      Object write context (ObjectReadContext) associated with this parser
      Since:
      3.0

    • currentTokenLocation

      public abstract TokenStreamLocation currentTokenLocation()
      Method that return the starting location of the current token; that is, position of the first character 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 TokenStreamLocation.NA due to not having access to input location information (when delegating actual decoding work to other library).

      Returns:
      Starting location of the token parser currently points to

    • currentLocation

      public abstract TokenStreamLocation currentLocation()
      Method that returns location of the last processed character; 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 TokenStreamLocation.NA due to not having access to input location information (when delegating actual decoding work to other library).

      Returns:
      Location of the last processed input unit (byte or character)

    • currentTokenCount

      public abstract long currentTokenCount()
      Get an approximate count of the number of tokens that have been read. This count is likely to be only updated if StreamReadConstraints.Builder.maxTokenCount(long) has been used to set a limit on the number of tokens that can be read.
      Returns:
      the number of tokens that have been read (-1 if the count is not available)

    • streamReadInputSource

      public abstract Object streamReadInputSource()
      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.

      NOTE: was named getInputSource() in Jackson 2.x.

      Returns:
      Input source this parser was configured with

    • currentValue

      public abstract Object currentValue()
      Helper method, usually equivalent to: getParsingContext().currentValue();

      Note that "current value" is NOT populated (or used) by Streaming parser; it is only used by higher-level data-binding functionality. The reason it is included here is that it can be stored and accessed hierarchically, and gets passed through data-binding.

      Returns:
      "Current value" for the current input context this parser has

    • assignCurrentValue

      public abstract void assignCurrentValue(Object v)
      Helper method, usually equivalent to: getParsingContext().assignCurrentValue(v);
      Parameters:
      v - "Current value" to assign to the current input context of this parser

    • canParseAsync

      public boolean canParseAsync()
      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 true, it is possible to call nonBlockingInputFeeder() to obtain object to use for feeding input; otherwise (false returned) input is read by blocking.

      Returns:
      True if this is a non-blocking ("asynchronous") parser

    • nonBlockingInputFeeder

      public NonBlockingInputFeeder nonBlockingInputFeeder()
      Method that will either return a feeder instance (if parser uses non-blocking, aka asynchronous access); or null for parsers that use blocking I/O.
      Returns:
      Input feeder to use with non-blocking (async) parsing

    • close

      public abstract void close()
      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 StreamReadFeature.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 AutoCloseable
      Specified by:
      close in interface Closeable

    • isClosed

      public abstract boolean isClosed()
      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 nextToken() (and the underlying stream may be closed). Closing may be due to an explicit call to close() or because parser has encountered end of input.
      Returns:
      True if this parser instance has been closed

    • releaseBuffered

      public int releaseBuffered(OutputStream out) throws JacksonException
      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 cannot.
      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 cannot be sent to OutputStream; otherwise number of bytes released (0 if there was nothing to release)
      Throws:
      JacksonException - if write to stream threw exception

    • releaseBuffered

      public int releaseBuffered(Writer w) throws JacksonException
      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 writer if possible; if underlying input is char-based it can released, if not (byte-based) it cannot.
      Parameters:
      w - Writer to which buffered but unprocessed content is written to
      Returns:
      -1 if the underlying content source is not char-based (that is, input cannot be sent to Writer; otherwise number of chars released (0 if there was nothing to release)
      Throws:
      JacksonException - if write using Writer threw exception

    • isEnabled

      public abstract boolean isEnabled(StreamReadFeature f)
      Method for checking whether specified StreamReadFeature is enabled.
      Parameters:
      f - Feature to check
      Returns:
      True if feature is enabled; false otherwise

    • streamReadFeatures

      public abstract int streamReadFeatures()
      Bulk access method for getting state of all standard StreamReadFeatures.
      Returns:
      Bit mask that defines current states of all standard StreamReadFeatures.
      Since:
      3.0

    • getSchema

      public FormatSchema getSchema()
      Method for accessing Schema that this parser uses, if any. Default implementation returns null.
      Returns:
      FormatSchema assigned to this parser, if any; null if none

    • streamReadCapabilities

      public abstract JacksonFeatureSet<StreamReadCapability> streamReadCapabilities()
      Accessor for getting metadata on capabilities of this parser, based on underlying data format being read (directly or indirectly).
      Returns:
      Set of read capabilities for content to read via this parser

    • streamReadConstraints

      public abstract StreamReadConstraints streamReadConstraints()
      Get the constraints to apply when performing streaming reads.
      Returns:
      Constraints applied to this parser

    • nextToken

      public abstract JsonToken nextToken() throws JacksonException
      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.
      Returns:
      Next token from the stream, if any found, or null to indicate end-of-input
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • nextValue

      public abstract JsonToken nextValue() throws JacksonException
      Iteration method that will advance stream enough to determine type of the next token that is a value type (including JSON Array and Object start/end markers). Or put another way, nextToken() will be called once, and if JsonToken.PROPERTY_NAME is returned, another time to get the value of the property. Method is most useful for iterating over value entries of JSON objects; Object property name will still be available by calling currentName() when parser points to the value.
      Returns:
      Next non-field-name token from the stream, if any found, or null to indicate end-of-input (or, for non-blocking parsers, JsonToken.NOT_AVAILABLE if no tokens were available yet)
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • skipChildren

      public abstract JsonParser skipChildren() throws JacksonException
      Method that will skip all child tokens of an array or object token that the parser currently points to, iff stream points to JsonToken.START_OBJECT or JsonToken.START_ARRAY. If not, it will do nothing. After skipping, stream will point to matching JsonToken.END_OBJECT or JsonToken.END_ARRAY (possibly skipping nested pairs of START/END OBJECT/ARRAY tokens as well as value tokens). The idea is that after calling this method, application will call nextToken() to point to the next available token, if any.
      Returns:
      This parser, to allow call chaining
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • finishToken

      public abstract void finishToken() throws JacksonException
      Method that may be used to force full handling of the current token so that even if lazy processing is enabled, the whole contents are read for possible retrieval. This is usually used to ensure that the token end location is available, as well as token contents (similar to what calling, say getStringCharacters(), would achieve).

      Note that for many dataformat implementations this method will not do anything; this is the default implementation unless overridden by sub-classes.

      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • nextName

      public abstract String nextName() throws JacksonException
      Method that fetches next token (as if calling nextToken()) and verifies whether it is JsonToken.PROPERTY_NAME; if it is, returns same as currentName(), otherwise null.

      NOTE: in Jackson 2.x method was called nextFieldName()

      Returns:
      Name of the the JsonToken.PROPERTY_NAME parser advanced to, if any; null if next token is of some other type
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • nextName

      public abstract boolean nextName(SerializableString str) throws JacksonException
      Method that fetches next token (as if calling nextToken()) and verifies whether it is JsonToken.PROPERTY_NAME with specified name and returns result of that comparison. It is functionally equivalent to: 
        return (nextToken() == JsonToken.PROPERTY_NAME) && str.getValue().equals(currentName());
      but may be faster for parser to verify, and can therefore be used if caller expects to get such a property name from input next.

      NOTE: in Jackson 2.x method was called nextFieldName()

      Parameters:
      str - Property name to compare next token to (if next token is JsonToken.PROPERTY_NAME)
      Returns:
      True if parser advanced to JsonToken.PROPERTY_NAME with specified name; false otherwise (different token or non-matching name)
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems

    • nextNameMatch

      public abstract int nextNameMatch(PropertyNameMatcher matcher) throws JacksonException
      Method that tries to match next token from stream as JsonToken.PROPERTY_NAME, and if so, further match it to one of pre-specified (field) names. If match succeeds, property index (non-negative `int`) is returned; otherwise one of marker constants from PropertyNameMatcher.
      Parameters:
      matcher - Matcher that will handle actual matching
      Returns:
      Index of the matched property name, if non-negative, or a negative error code otherwise (see PropertyNameMatcher for details)
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException
      Since:
      3.0

    • currentNameMatch

      public abstract int currentNameMatch(PropertyNameMatcher matcher)
      Method that verifies that the current token (see currentToken()) is JsonToken.PROPERTY_NAME and if so, further match that associated name (see currentName()) to one of pre-specified (property) names. If there is a match succeeds, the property index (non-negative int) is returned; otherwise one of marker constants from PropertyNameMatcher is returned.
      Parameters:
      matcher - Matcher that will handle actual matching
      Returns:
      Index of the matched property name, if non-negative, or a negative error code otherwise (see PropertyNameMatcher for details)
      Since:
      3.0

    • nextStringValue

      public String nextStringValue() throws JacksonException
      Method that fetches next token (as if calling nextToken()) and if it is JsonToken.VALUE_STRING returns contained String value; otherwise returns null. It is functionally equivalent to: 
        return (nextToken() == JsonToken.VALUE_STRING) ? getString() : null;
      but may be faster for parser to process, and can therefore be used if caller expects to get a String value next from input.
      Returns:
      String value of JsonToken.VALUE_STRING token parser advanced to; or null if next token is of some other type
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • nextIntValue

      public int nextIntValue(int defaultValue) throws JacksonException
      Method that fetches next token (as if calling nextToken()) and if it is JsonToken.VALUE_NUMBER_INT returns 32-bit int value; otherwise returns specified default value It is functionally equivalent to: 
        return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getIntValue() : defaultValue;
      but may be faster for parser to process, and can therefore be used if caller expects to get an int value next from input.

      NOTE: value checks are performed similar to getIntValue()

      Parameters:
      defaultValue - Value to return if next token is NOT of type JsonToken.VALUE_NUMBER_INT
      Returns:
      Integer (int) value of the JsonToken.VALUE_NUMBER_INT token parser advanced to; or defaultValue if next token is of some other type
      Throws:
      JacksonException - for low-level read issues
      StreamReadException - for decoding problems
      InputCoercionException - if integer number does not fit in Java int

    • nextLongValue

      public long nextLongValue(long defaultValue) throws JacksonException
      Method that fetches next token (as if calling nextToken()) and if it is JsonToken.VALUE_NUMBER_INT returns 64-bit long value; otherwise returns specified default value It is functionally equivalent to: 
        return (nextToken() == JsonToken.VALUE_NUMBER_INT) ? getLongValue() : defaultValue;
      but may be faster for parser to process, and can therefore be used if caller expects to get a long value next from input.

      NOTE: value checks are performed similar to getLongValue()

      Parameters:
      defaultValue - Value to return if next token is NOT of type JsonToken.VALUE_NUMBER_INT
      Returns:
      long value of the JsonToken.VALUE_NUMBER_INT token parser advanced to; or defaultValue if next token is of some other type
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      InputCoercionException - if integer number does not fit in Java long
      JacksonException

    • nextBooleanValue

      public Boolean nextBooleanValue() throws JacksonException
      Method that fetches next token (as if calling nextToken()) and if it is JsonToken.VALUE_TRUE or JsonToken.VALUE_FALSE returns matching Boolean value; otherwise return null. It is functionally equivalent to: 
        JsonToken t = nextToken();
  if (t == JsonToken.VALUE_TRUE) return Boolean.TRUE;
  if (t == JsonToken.VALUE_FALSE) return Boolean.FALSE;
  return null;
      but may be faster for parser to process, and can therefore be used if caller expects to get a Boolean value next from input.
      Returns:
      Boolean value of the JsonToken.VALUE_TRUE or JsonToken.VALUE_FALSE token parser advanced to; or null if next token is of some other type
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • currentToken

      public abstract JsonToken currentToken()
      Accessor to find which token parser currently points to, if any; null will be returned if none. If return value is non-null, data associated with the token is available via other accessor methods.
      Returns:
      Type of the token this parser currently points to, if any: null before any tokens have been read, and after end-of-input has been encountered, as well as if the current token has been explicitly cleared.

    • currentTokenId

      public abstract int currentTokenId()
      Method similar to currentToken() but that returns an int instead of JsonToken (enum value).

      Use of int directly is typically more efficient on switch statements, so this method may be useful when building low-overhead codecs. Note, however, that effect may not be big enough to matter: make sure to profile performance before deciding to use this method.

      Returns:
      int matching one of constants from JsonTokenId.

    • hasCurrentToken

      public abstract boolean hasCurrentToken()
      Method for checking whether parser currently points to a token (and data for that token is available). Equivalent to check for parser.getCurrentToken() != null.
      Returns:
      True if the parser just returned a valid token via nextToken(); false otherwise (parser was just constructed, encountered end-of-input and returned null from nextToken(), or the token has been consumed)

    • hasTokenId

      public abstract boolean hasTokenId(int id)
      Method that is functionally equivalent to: return currentTokenId() == id but may be more efficiently implemented.

      Note that no traversal or conversion is performed; so in some cases calling method like isExpectedStartArrayToken() is necessary instead.

      Parameters:
      id - Token id to match (from (@link JsonTokenId})
      Returns:
      True if the parser current points to specified token

    • hasToken

      public abstract boolean hasToken(JsonToken t)
      Method that is functionally equivalent to: return currentToken() == t but may be more efficiently implemented.

      Note that no traversal or conversion is performed; so in some cases calling method like isExpectedStartArrayToken() is necessary instead.

      Parameters:
      t - Token to match
      Returns:
      True if the parser current points to specified token

    • isExpectedStartArrayToken

      public abstract boolean isExpectedStartArrayToken()
      Specialized accessor that can be used to verify that the current token indicates start array (usually meaning that current token is JsonToken.START_ARRAY) when start array is expected. For some specialized parsers this can return true for other cases as well; this is usually done to emulate arrays in cases underlying format is ambiguous (XML, for example, has no format-level difference between Objects and Arrays; it just has elements).

      Default implementation is equivalent to: 

         currentToken() == JsonToken.START_ARRAY
      but may be overridden by custom parser implementations.
      Returns:
      True if the current token can be considered as a start-array marker (such JsonToken.START_ARRAY); false if not

    • isExpectedStartObjectToken

      public abstract boolean isExpectedStartObjectToken()
      Similar to isExpectedStartArrayToken(), but checks whether stream currently points to JsonToken.START_OBJECT.
      Returns:
      True if the current token can be considered as a start-array marker (such JsonToken.START_OBJECT); false if not

    • isExpectedNumberIntToken

      public abstract boolean isExpectedNumberIntToken()
      Similar to isExpectedStartArrayToken(), but checks whether stream currently points to JsonToken.VALUE_NUMBER_INT.

      The initial use case is for XML backend to efficiently (attempt to) coerce textual content into numbers.

      Returns:
      True if the current token can be considered as a start-array marker (such JsonToken.VALUE_NUMBER_INT); false if not

    • isNaN

      public abstract boolean isNaN()
      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.

      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.

    • clearCurrentToken

      public abstract void clearCurrentToken()
      Method called to "consume" the current token by effectively removing it so that hasCurrentToken() returns false, and currentToken() null). Cleared token value can still be accessed by calling getLastClearedToken() (if absolutely needed), but usually isn't.

      Method was added to be used by the optional data binder, since it has to be able to consume last token used for binding (so that it will not be used again).

    • getLastClearedToken

      public abstract JsonToken getLastClearedToken()
      Method that can be called to get the last token that was cleared using clearCurrentToken(). This is not necessarily the latest token read. Will return null if no tokens have been cleared, or if parser has been closed.
      Returns:
      Last cleared token, if any; null otherwise

    • currentName

      public abstract String currentName()
      Method that can be called to get the name associated with the current token: for JsonToken.PROPERTY_NAMEs it will be the same as what getString() returns; for Object property values it will be the preceding property name; and for others (array element, root-level values) null.
      Returns:
      Name of the current property name, if any, in the parsing context (null if none)

    • getString

      public abstract String getString() throws JacksonException
      Method for accessing textual representation of the current token; if no current token (before first call to nextToken(), or after encountering end-of-input), returns null. Method can be called for any token type.
      Returns:
      String value associated with the current token (one returned by nextToken() or other iteration methods)
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • getString

      public abstract int getString(Writer writer) throws JacksonException
      Method to read the textual representation of the current token in chunks and pass it to the given Writer. Functionally same as calling: 
        writer.write(parser.getString());
      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.

      NOTE: String value will still be buffered (usually using TextBuffer) and will be accessible with other getString() calls (that is, it will not be consumed). So this accessor only avoids construction of String compared to plain getString() method.

      NOTE: In Jackson 2.x this method was called getString(Writer).

      Parameters:
      writer - Writer to write String value to
      Returns:
      The number of characters written to the Writer
      Throws:
      JacksonIOException - for low-level read issues, or failed write using Writer
      StreamReadException - for decoding problems
      JacksonException

    • getStringCharacters

      public abstract char[] getStringCharacters() throws JacksonException
      Method similar to getString(), 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:
      • String contents are not guaranteed to start at index 0 (rather, call getStringOffset()) to know the actual offset
      • Length of string contents may be less than the length of returned buffer: call getStringLength() 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 getString()) is to avoid construction of a String object (which will make a copy of contents).

      Returns:
      Buffer that contains the current textual value (but not necessarily at offset 0, and not necessarily until the end of buffer)
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • getStringLength

      public abstract int getStringLength() throws JacksonException
      Accessor used with getStringCharacters(), to know length of String stored in returned buffer.
      Returns:
      Number of characters within buffer returned by getStringCharacters() that are part of textual content of the current token.
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • getStringOffset

      public abstract int getStringOffset() throws JacksonException
      Accessor used with getStringCharacters(), to know offset of the first text content character within buffer.
      Returns:
      Offset of the first character within buffer returned by getStringCharacters() that is part of textual content of the current token.
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • hasStringCharacters

      public abstract boolean hasStringCharacters()
      Method that can be used to determine whether calling of getStringCharacters() would be the most efficient way to access String value for the event parser currently points to (compared to getString()).
      Returns:
      True if parser currently has character array that can be efficiently returned via getStringCharacters(); false means that it may or may not exist

    • getText

      @Deprecated public String getText() throws JacksonException
      Deprecated.
      since 3.0 use getString() instead.
      Deprecated alias for getString(): MAY be removed in a 3.x version past 3.0; only included to help initial migration.
      Throws:
      JacksonException

    • getTextCharacters

      @Deprecated public char[] getTextCharacters() throws JacksonException
      Deprecated.
      since 3.0 use getStringCharacters() instead.
      Deprecated alias for getStringCharacters(): MAY be removed in a 3.x version past 3.0; only included to help initial migration.
      Throws:
      JacksonException

    • getTextLength

      @Deprecated public int getTextLength() throws JacksonException
      Deprecated.
      since 3.0 use getStringLength() instead.
      Deprecated alias for getStringLength(): MAY be removed in a 3.x version past 3.0; only included to help initial migration.
      Throws:
      JacksonException

    • getTextOffset

      @Deprecated public int getTextOffset() throws JacksonException
      Deprecated.
      since 3.0 use getStringOffset() instead.
      Deprecated alias for getStringOffset(): MAY be removed in a 3.x version past 3.0; only included to help initial migration.
      Throws:
      JacksonException

    • getNumberValue

      public abstract Number getNumberValue() throws InputCoercionException
      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.
      Returns:
      Numeric value of the current token in its most optimal representation
      Throws:
      InputCoercionException - If the current token is not of numeric type

    • getNumberValueExact

      public abstract Number getNumberValueExact() throws InputCoercionException
      Method similar to getNumberValue() with the difference that for floating-point numbers value returned may be BigDecimal if the underlying format does not store floating-point numbers using native representation: for example, textual formats represent numbers as Strings (which are 10-based), and conversion to Double is potentially lossy operation.

      Default implementation simply returns getNumberValue()

      Returns:
      Numeric value of the current token using most accurate representation
      Throws:
      InputCoercionException - If the current token is not of numeric type

    • getNumberValueDeferred

      public abstract Object getNumberValueDeferred() throws InputCoercionException
      Method similar to getNumberValue() but that returns either same Number value as getNumberValue() (if already decoded), or String representation of as-of-yet undecoded number. Typically textual formats allow deferred decoding from String, whereas binary formats either decode numbers eagerly or have binary representation from which to decode value to return.

      Same constraints apply to calling this method as to getNumberValue(): current token must be either JsonToken.VALUE_NUMBER_INT or JsonToken.VALUE_NUMBER_FLOAT; otherwise an exception is thrown

      Default implementation simply returns getNumberValue()

      Returns:
      Either Number (for already decoded numbers) or String (for deferred decoding).
      Throws:
      InputCoercionException - If the current token is not of numeric type

    • getNumberType

      public abstract JsonParser.NumberType getNumberType()
      If current token is of type JsonToken.VALUE_NUMBER_INT or JsonToken.VALUE_NUMBER_FLOAT, returns one of JsonParser.NumberType constants; otherwise returns null.

      NOTE: in Jackson 2.x, an exception was wrong if called for non-numeric token.

      Returns:
      Type of current number, if parser points to numeric token; null otherwise

    • getNumberTypeFP

      public abstract JsonParser.NumberTypeFP getNumberTypeFP()
      If current token is of type JsonToken.VALUE_NUMBER_FLOAT, returns one of JsonParser.NumberTypeFP constants; otherwise returns JsonParser.NumberTypeFP.UNKNOWN.
      Returns:
      Type of current number, if parser points to numeric token; null otherwise

    • getByteValue

      public abstract byte getByteValue() throws InputCoercionException
      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 byte primitive type. Note that in addition to "natural" input range of [-128, 127], this also allows "unsigned 8-bit byte" values [128, 255]: but for this range value will be translated by truncation, leading to sign change.

      It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling getDoubleValue() and then casting; except for possible overflow/underflow exception.

      Note: if the resulting integer value falls outside range of [-128, 255], a InputCoercionException will be thrown to indicate numeric overflow/underflow.

      Returns:
      Current number value as byte (if numeric token within range of [-128, 255]); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getShortValue

      public abstract short getShortValue() throws InputCoercionException
      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 short primitive type. It can also be called for JsonToken.VALUE_NUMBER_FLOAT; if so, it is equivalent to calling getDoubleValue() and then casting; except for possible overflow/underflow exception.

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

      Returns:
      Current number value as short (if numeric token within Java 16-bit signed short range); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getIntValue

      public abstract int getIntValue() throws InputCoercionException
      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 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.

      Returns:
      Current number value as int (if numeric token within Java 32-bit signed int range); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getLongValue

      public abstract long getLongValue() throws InputCoercionException
      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 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.

      Returns:
      Current number value as long (if numeric token within Java 32-bit signed long range); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getBigIntegerValue

      public abstract BigInteger getBigIntegerValue() throws InputCoercionException
      Numeric accessor that can be called when the current token is of type JsonToken.VALUE_NUMBER_INT and it cannot 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 getDecimalValue() and then constructing a BigInteger from that value.
      Returns:
      Current number value as BigInteger (if numeric token); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number

    • getFloatValue

      public abstract float getFloatValue() throws InputCoercionException
      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 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.

      Returns:
      Current number value as float (if numeric token within Java float range); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getDoubleValue

      public abstract double getDoubleValue() throws InputCoercionException
      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 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.

      Returns:
      Current number value as double (if numeric token within Java double range); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number OR numeric value exceeds allowed range

    • getDecimalValue

      public abstract BigDecimal getDecimalValue() throws InputCoercionException
      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.
      Returns:
      Current number value as BigDecimal (if numeric token); otherwise exception thrown
      Throws:
      InputCoercionException - If either token type is not a number

    • getBooleanValue

      public abstract boolean getBooleanValue() throws InputCoercionException
      Convenience accessor that can be called when the current token is JsonToken.VALUE_TRUE or JsonToken.VALUE_FALSE, to return matching boolean value. If the current token is of some other type, InputCoercionException will be thrown
      Returns:
      True if current token is JsonToken.VALUE_TRUE, false if current token is JsonToken.VALUE_FALSE; otherwise throws InputCoercionException
      Throws:
      InputCoercionException - if the current token is not of boolean type

    • getEmbeddedObject

      public abstract Object getEmbeddedObject()
      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 getBinaryValue().

      Returns:
      Embedded value (usually of "native" type supported by format) for the current token, if any; null otherwise

    • getBinaryValue

      public abstract byte[] getBinaryValue(Base64Variant bv) throws JacksonException
      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 getString() 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.

      Parameters:
      bv - Expected variant of base64 encoded content (see Base64Variants for definitions of "standard" variants).
      Returns:
      Decoded binary data
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • getBinaryValue

      public byte[] getBinaryValue() throws JacksonException
      Convenience alternative to getBinaryValue(Base64Variant) that defaults to using Base64Variants.getDefaultVariant() as the default encoding.
      Returns:
      Decoded binary data
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • readBinaryValue

      public int readBinaryValue(OutputStream out) throws JacksonException
      Method that can be used as an alternative to getBinaryValue(), especially when value can be large. The main difference (beyond method of returning content using OutputStream instead of as byte array) is that content will NOT remain accessible after method returns: any content processed will be consumed and is not buffered in any way. If caller needs buffering, it has to implement it.
      Parameters:
      out - Output stream to use for passing decoded binary data
      Returns:
      Number of bytes that were decoded and written via OutputStream
      Throws:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • readBinaryValue

      public int readBinaryValue(Base64Variant bv, OutputStream out) throws JacksonException
      Similar to readBinaryValue(OutputStream) but allows explicitly specifying base64 variant to use.
      Parameters:
      bv - 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:
      JacksonIOException - for low-level read issues
      StreamReadException - for decoding problems
      JacksonException

    • getValueAsBoolean

      public boolean getValueAsBoolean()
      Method that will try to convert value of current token to a boolean. JSON booleans map naturally; integer numbers other than 0 map to true, and 0 maps to false and Strings 'true' and 'false' map to corresponding values.

      If representation cannot be converted to a boolean value (including structured types like Objects and Arrays), default value of false will be returned; no exceptions are thrown.

      Returns:
      boolean value current token is converted to, if possible; or false if not

    • getValueAsBoolean

      public abstract boolean getValueAsBoolean(boolean def)
      Method that will try to convert value of current token to a boolean. JSON booleans map naturally; integer numbers other than 0 map to true, and 0 maps to false and Strings 'true' and 'false' map to corresponding values.

      If representation cannot be converted to a boolean value (including structured types like Objects and Arrays), specified def will be returned; no exceptions are thrown.

      Parameters:
      def - Default value to return if conversion to boolean is not possible
      Returns:
      boolean value current token is converted to, if possible; def otherwise

    • getValueAsInt

      public int getValueAsInt() throws InputCoercionException
      Method that will try to convert value of current token to a Java int value. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation cannot be converted to an int (including structured type markers like start/end Object/Array) default value of 0 will be returned; no exceptions are thrown.

      Returns:
      int value current token is converted to, if possible; default value otherwise otherwise
      Throws:
      InputCoercionException - If numeric value exceeds int range

    • getValueAsInt

      public int getValueAsInt(int def) throws InputCoercionException
      Method that will try to convert value of current token to a int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation cannot be converted to an int (including structured type markers like start/end Object/Array) specified def will be returned; no exceptions are thrown.

      Parameters:
      def - Default value to return if conversion to int is not possible
      Returns:
      int value current token is converted to, if possible; def otherwise
      Throws:
      InputCoercionException - If numeric value exceeds int range

    • getValueAsLong

      public long getValueAsLong() throws InputCoercionException
      Method that will try to convert value of current token to a long. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation cannot be converted to a long (including structured type markers like start/end Object/Array) default value of 0L will be returned; no exceptions are thrown.

      Returns:
      long value current token is converted to, if possible; default value otherwise
      Throws:
      InputCoercionException - If numeric value exceeds long range

    • getValueAsLong

      public long getValueAsLong(long def) throws InputCoercionException
      Method that will try to convert value of current token to a long. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation cannot be converted to a long (including structured type markers like start/end Object/Array) specified def will be returned; no exceptions are thrown.

      Parameters:
      def - Default value to return if conversion to long is not possible
      Returns:
      long value current token is converted to, if possible; def otherwise
      Throws:
      InputCoercionException - If numeric value exceeds long range

    • getValueAsDouble

      public double getValueAsDouble() throws InputCoercionException
      Method that will try to convert value of current token to a Java double. Numbers are coerced using default Java rules; booleans convert to 0.0 (false) and 1.0 (true), and Strings are parsed using default Java language floating point parsing rules.

      If representation cannot be converted to a double (including structured types like Objects and Arrays), default value of 0.0 will be returned; no exceptions are thrown.

      Returns:
      double value current token is converted to, if possible; default value otherwise
      Throws:
      InputCoercionException - If numeric value exceeds double range

    • getValueAsDouble

      public double getValueAsDouble(double def) throws InputCoercionException
      Method that will try to convert value of current token to a Java double. Numbers are coerced using default Java rules; booleans convert to 0.0 (false) and 1.0 (true), and Strings are parsed using default Java language floating point parsing rules.

      If representation cannot be converted to a double (including structured types like Objects and Arrays), specified def will be returned; no exceptions are thrown.

      Parameters:
      def - Default value to return if conversion to double is not possible
      Returns:
      double value current token is converted to, if possible; def otherwise
      Throws:
      InputCoercionException - If numeric value exceeds double range

    • getValueAsString

      public String getValueAsString()
      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 cannot 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.
      Returns:
      String value current token is converted to, if possible; null otherwise

    • getValueAsString

      public abstract String getValueAsString(String def)
      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 cannot 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.
      Parameters:
      def - Default value to return if conversion to String is not possible
      Returns:
      String value current token is converted to, if possible; def otherwise

    • canReadObjectId

      public boolean canReadObjectId()
      Introspection method that may be called to see if the underlying data format supports some kind of Object Ids natively (many do not; for example, JSON doesn't).

      Default implementation returns true; overridden by data formats that do support native Object Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it cannot use native object ids.

      Returns:
      True if the format being read supports native Object Ids; false if not

    • canReadTypeId

      public boolean canReadTypeId()
      Introspection method that may be called to see if the underlying data format supports some kind of Type Ids natively (many do not; for example, JSON doesn't).

      Default implementation returns true; overridden by data formats that do support native Type Ids. Caller is expected to either use a non-native notation (explicit property or such), or fail, in case it cannot use native type ids.

      Returns:
      True if the format being read supports native Type Ids; false if not

    • getObjectId

      public Object getObjectId()
      Method that can be called to check whether current token (one that was just read) has an associated Object id, and if so, return it. Note that while typically caller should check with canReadObjectId() first, it is not illegal to call this method even if that method returns true; but if so, it will return null. This may be used to simplify calling code.

      Default implementation will simply return null.

      Returns:
      Native Object id associated with the current token, if any; null if none

    • getTypeId

      public Object getTypeId()
      Method that can be called to check whether current token (one that was just read) has an associated type id, and if so, return it. Note that while typically caller should check with canReadTypeId() first, it is not illegal to call this method even if that method returns true; but if so, it will return null. This may be used to simplify calling code.

      Default implementation will simply return null.

      Returns:
      Native Type Id associated with the current token, if any; null if none

    • readValueAs

      public abstract <T> T readValueAs(Class<T> valueType) throws JacksonException
      Method to deserialize stream content into a non-container type (it can be an array type, however): typically a bean, array or a wrapper type (like Boolean).
      Note: method can only be called if the parser has been constructed with a linkage to ObjectReadContext; this is true if constructed by databinding layer above, or by factory method that takes in context object.

      This method may advance the event stream, for structured values the current token will be the closing end marker (END_ARRAY, END_OBJECT) of the bound structure. For non-structured values (and for JsonToken.VALUE_EMBEDDED_OBJECT) stream is not advanced.

      Note: this method should NOT be used if the result type is a container (Collection or Map. The reason is that due to type erasure, key and value types cannot be introspected when using this method.

      Type Parameters:
      T - Nominal type parameter to specify expected node type to reduce need to cast result value
      Parameters:
      valueType - Type to bind content to
      Returns:
      Java value read from content
      Throws:
      JacksonException - if there is either an underlying I/O problem or decoding issue at format layer

    • readValueAs

      public abstract <T> T readValueAs(TypeReference<T> valueTypeRef) throws JacksonException
      Method to deserialize stream content into a Java type, reference to which is passed as argument. Type is passed using so-called "super type token" and specifically needs to be used if the root type is a parameterized (generic) container type.
      Note: method can only be called if the parser has been constructed with a linkage to ObjectReadContext; this is true if constructed by databinding layer above, or by factory method that takes in context object.

      This method may advance the event stream, for structured types the current token will be the closing end marker (END_ARRAY, END_OBJECT) of the bound structure. For non-structured types (and for JsonToken.VALUE_EMBEDDED_OBJECT) stream is not advanced.

      Type Parameters:
      T - Nominal type parameter to specify expected node type to reduce need to cast result value
      Parameters:
      valueTypeRef - Type to bind content to
      Returns:
      Java value read from content
      Throws:
      JacksonException - if there is either an underlying I/O problem or decoding issue at format layer

    • readValueAs

      public abstract <T> T readValueAs(ResolvedType type) throws JacksonException
      Throws:
      JacksonException

    • readValueAsTree

      public abstract <T extends TreeNode> T readValueAsTree() throws JacksonException
      Method to deserialize stream content into equivalent "tree model", represented by root TreeNode of resulting model. For Array values it will an array node (with child nodes), for Object values object node (with child nodes), and for other types matching leaf node type. Empty or whitespace documents are null.
      Note: method can only be called if the parser has been constructed with a linkage to ObjectReadContext; this is true if constructed by databinding layer above, or by factory method that takes in context object.
      Type Parameters:
      T - Nominal type parameter for result node type (to reduce need for casting)
      Returns:
      root of the document, or null if empty or whitespace.
      Throws:
      JacksonException - if there is either an underlying I/O problem or decoding issue at format layer

    • _reportUnsupportedOperation

      protected void _reportUnsupportedOperation()
      Helper method to call for operations that are not supported by parser implementation.

    • _constructReadException

      protected StreamReadException _constructReadException(String msg)
      Helper method for constructing StreamReadException based on current state of the parser
      Parameters:
      msg - Base exception message to construct exception with
      Returns:
      StreamReadException constructed

    • _constructReadException

      protected StreamReadException _constructReadException(String msg, Object arg)

    • _constructReadException

      protected StreamReadException _constructReadException(String msg, Object arg1, Object arg2)

    • _constructReadException

      protected StreamReadException _constructReadException(String msg, Object arg1, Object arg2, Object arg3)

    • _constructReadException

      protected StreamReadException _constructReadException(String msg, Throwable t)
      Helper method for constructing StreamReadException based on current state of the parser and indicating that the given Throwable is the root cause.
      Parameters:
      msg - Base exception message to construct exception with
      t - Root cause to assign
      Returns:
      Read exception (of type StreamReadException) constructed

    • _constructReadException

      protected StreamReadException _constructReadException(String msg, TokenStreamLocation loc)
      Helper method for constructing StreamReadException based on current state of the parser, except for specified TokenStreamLocation for problem location (which may not be the exact current location)
      Parameters:
      msg - Base exception message to construct exception with
      loc - Error location to report
      Returns:
      Read exception (of type StreamReadException) constructed
      Since:
      2.13