Package com.fasterxml.jackson.core.base

Class ParserMinimalBase

  • All Implemented Interfaces:
    Versioned, java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    ParserBase, TreeTraversingParser
    public abstract class ParserMinimalBase
extends JsonParser
    Intermediate base class used by all Jackson JsonParser implementations, but does not add any additional fields that depend on particular method of obtaining input.

    Note that 'minimal' here mostly refers to minimal number of fields (size) and functionality that is specific to certain types of parser implementations; but not necessarily to number of methods.

    • Method Detail

      • nextToken

        public abstract 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 JsonParser
        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

      • currentToken

        public JsonToken currentToken()
        Description copied from class: JsonParser
        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.
        Overrides:
        currentToken in class JsonParser
        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 int currentTokenId()
        Description copied from class: JsonParser
        Method similar to JsonParser.getCurrentToken() 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.

        Overrides:
        currentTokenId in class JsonParser
        Returns:
        int matching one of constants from JsonTokenId.

      • getCurrentToken

        public JsonToken getCurrentToken()
        Description copied from class: JsonParser
        Alias for JsonParser.currentToken(), may be deprecated sometime after Jackson 2.13 (will be removed from 3.0).
        Specified by:
        getCurrentToken in class JsonParser
        Returns:
        Type of the token this parser currently points to, if any: null before any tokens have been read, and

      • hasCurrentToken

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

      • hasTokenId

        public boolean hasTokenId​(int id)
        Description copied from class: JsonParser
        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 JsonParser.isExpectedStartArrayToken() is necessary instead.

        Specified by:
        hasTokenId in class JsonParser
        Parameters:
        id - Token id to match (from (@link JsonTokenId})
        Returns:
        True if the parser current points to specified token

      • hasToken

        public boolean hasToken​(JsonToken t)
        Description copied from class: JsonParser
        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 JsonParser.isExpectedStartArrayToken() is necessary instead.

        Specified by:
        hasToken in class JsonParser
        Parameters:
        t - Token to match
        Returns:
        True if the parser current points to specified token

      • isExpectedStartArrayToken

        public boolean isExpectedStartArrayToken()
        Description copied from class: JsonParser
        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.
        Overrides:
        isExpectedStartArrayToken in class JsonParser
        Returns:
        True if the current token can be considered as a start-array marker (such JsonToken.START_ARRAY); false if not

      • nextValue

        public JsonToken nextValue()
                    throws java.io.IOException
        Description copied from class: JsonParser
        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.FIELD_NAME is returned, another time to get the value for the field. Method is most useful for iterating over value entries of JSON objects; field name will still be available by calling JsonParser.getCurrentName() when parser points to the value.
        Specified by:
        nextValue in class JsonParser
        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:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • skipChildren

        public JsonParser skipChildren()
                        throws java.io.IOException
        Description copied from class: JsonParser
        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 JsonParser.nextToken() to point to the next available token, if any.
        Specified by:
        skipChildren in class JsonParser
        Returns:
        This parser, to allow call chaining
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getCurrentName

        public abstract java.lang.String getCurrentName()
                                         throws java.io.IOException
        Description copied from class: JsonParser
        Alias of JsonParser.currentName().
        Specified by:
        getCurrentName in class JsonParser
        Returns:
        Name of the current field in the parsing context
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • close

        public abstract 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 JsonParser
        Throws:
        java.io.IOException - if there is either an underlying I/O problem

      • isClosed

        public abstract 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 JsonParser
        Returns:
        True if this parser instance has been closed

      • getParsingContext

        public abstract 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 JsonParser
        Returns:
        Stream input context (JsonStreamContext) associated with this parser

      • getLastClearedToken

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

      • overrideCurrentName

        public abstract 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 JsonParser
        Parameters:
        name - Name to use as the current name; may be null.

      • getText

        public abstract java.lang.String getText()
                                  throws java.io.IOException
        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 JsonParser
        Returns:
        Textual value associated with the current token (one returned by JsonParser.nextToken() or other iteration methods)
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getTextCharacters

        public abstract 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 JsonParser
        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

      • hasTextCharacters

        public abstract 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 JsonParser
        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

      • getBinaryValue

        public abstract 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 JsonParser
        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

      • getValueAsBoolean

        public boolean getValueAsBoolean​(boolean defaultValue)
                          throws java.io.IOException
        Description copied from class: JsonParser
        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 can not be converted to a boolean value (including structured types like Objects and Arrays), specified def will be returned; no exceptions are thrown.

        Overrides:
        getValueAsBoolean in class JsonParser
        Parameters:
        defaultValue - Default value to return if conversion to boolean is not possible
        Returns:
        boolean value current token is converted to, if possible; def otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsInt

        public int getValueAsInt()
                  throws java.io.IOException
        Description copied from class: JsonParser
        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 can not 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.

        Overrides:
        getValueAsInt in class JsonParser
        Returns:
        int value current token is converted to, if possible; exception thrown otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsInt

        public int getValueAsInt​(int defaultValue)
                  throws java.io.IOException
        Description copied from class: JsonParser
        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 can not be converted to an int (including structured type markers like start/end Object/Array) specified def will be returned; no exceptions are thrown.

        Overrides:
        getValueAsInt in class JsonParser
        Parameters:
        defaultValue - Default value to return if conversion to int is not possible
        Returns:
        int value current token is converted to, if possible; def otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsLong

        public long getValueAsLong()
                    throws java.io.IOException
        Description copied from class: JsonParser
        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 can not 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.

        Overrides:
        getValueAsLong in class JsonParser
        Returns:
        long value current token is converted to, if possible; exception thrown otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsLong

        public long getValueAsLong​(long defaultValue)
                    throws java.io.IOException
        Description copied from class: JsonParser
        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 can not be converted to a long (including structured type markers like start/end Object/Array) specified def will be returned; no exceptions are thrown.

        Overrides:
        getValueAsLong in class JsonParser
        Parameters:
        defaultValue - Default value to return if conversion to long is not possible
        Returns:
        long value current token is converted to, if possible; def otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsDouble

        public double getValueAsDouble​(double defaultValue)
                        throws java.io.IOException
        Description copied from class: JsonParser
        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 can not be converted to a double (including structured types like Objects and Arrays), specified def will be returned; no exceptions are thrown.

        Overrides:
        getValueAsDouble in class JsonParser
        Parameters:
        defaultValue - Default value to return if conversion to double is not possible
        Returns:
        double value current token is converted to, if possible; def otherwise
        Throws:
        java.io.IOException - for low-level read issues, or JsonParseException for decoding problems

      • getValueAsString

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

      • getValueAsString

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