Class JSONTokener


  • public class JSONTokener
    extends Object
    A JSONTokener takes a source string and extracts characters and tokens from it. It is used by the JSONObject and JSONArray constructors to parse JSON source strings.
    Version:
    4
    Author:
    JSON.org
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static String LEGACY_NUMBER_COERCION_PROPERTY
      Compatibility switch for numeric coercion semantics inherited from json-lib 2.x, which in turn aligned with commons-lang 2.6 (org.apache.commons.lang.math.NumberUtils) behavior.
    • Constructor Summary

      Constructors 
      Constructor Description
      JSONTokener​(String s)
      Construct a JSONTokener from a string.
    • Field Detail

      • LEGACY_NUMBER_COERCION_PROPERTY

        public static final String LEGACY_NUMBER_COERCION_PROPERTY
        Compatibility switch for numeric coercion semantics inherited from json-lib 2.x, which in turn aligned with commons-lang 2.6 (org.apache.commons.lang.math.NumberUtils) behavior.

        Default is true to preserve historical rounding/coercion patterns.

        See Also:
        Constant Field Values
    • Constructor Detail

      • JSONTokener

        public JSONTokener​(String s)
        Construct a JSONTokener from a string.
        Parameters:
        s - A source string.
    • Method Detail

      • dehexchar

        public static int dehexchar​(char c)
        Get the hex value of a character (base16).
        Parameters:
        c - A character between '0' and '9' or between 'A' and 'F' or between 'a' and 'f'.
        Returns:
        An int between 0 and 15, or -1 if c was not a hex digit.
      • back

        public void back()
        Back up one character. This provides a sort of lookahead capability, so that you can test for a digit or letter before attempting to parse the next number or identifier.
      • length

        public int length()
      • matches

        public boolean matches​(String pattern)
      • startsWith

        public boolean startsWith​(String prefix)
      • more

        public boolean more()
        Determine if the source string still contains characters that next() can consume.
        Returns:
        true if not yet at the end of the source.
      • next

        public char next()
        Get the next character in the source string.
        Returns:
        The next character, or 0 if past the end of the source string.
      • next

        public char next​(char c)
        Consume the next character, and check that it matches a specified character.
        Parameters:
        c - The character to match.
        Returns:
        The character.
        Throws:
        JSONException - if the character does not match.
      • next

        public String next​(int n)
        Get the next n characters.
        Parameters:
        n - The number of characters to take.
        Returns:
        A string of n characters.
        Throws:
        JSONException - Substring bounds error if there are not n characters remaining in the source string.
      • nextClean

        public char nextClean()
        Get the next char in the string, skipping whitespace and comments (slashslash, slashstar, and hash).
        Returns:
        A character, or 0 if there are no more characters.
        Throws:
        JSONException
      • nextString

        public String nextString​(char quote)
        Return the characters up to the next close quote character. Backslash processing is done. The formal JSON format does not allow strings in single quotes, but an implementation is allowed to accept them.
        Parameters:
        quote - The quoting character, either " (double quote) or ' (single quote).
        Returns:
        A String.
        Throws:
        JSONException - Unterminated string.
      • nextTo

        public String nextTo​(char d)
        Get the text up but not including the specified character or the end of line, whichever comes first.
        Parameters:
        d - A delimiter character.
        Returns:
        A string.
      • nextTo

        public String nextTo​(String delimiters)
        Get the text up but not including one of the specified delimeter characters or the end of line, whichever comes first.
        Parameters:
        delimiters - A set of delimiter characters.
        Returns:
        A string, trimmed.
      • nextValue

        public Object nextValue()
        Get the next value. The value can be a Boolean, Double, Integer, JSONArray, JSONObject, Long, or String, or the JSONObject.NULL object.
        Returns:
        An object.
        Throws:
        JSONException - If syntax error.
      • nextValue

        public Object nextValue​(JsonConfig jsonConfig)
        Get the next value. The value can be a Boolean, Double, Integer, JSONArray, JSONObject, Long, or String, or the JSONObject.NULL object.
        Returns:
        An object.
        Throws:
        JSONException - If syntax error.
      • peek

        public char peek()
        Look at the next character in the source string.
        Returns:
        The next character, or 0 if past the end of the source string.
      • reset

        public void reset()
      • skipPast

        public void skipPast​(String to)
        Skip characters until past the requested string. If it is not found, we are left at the end of the source.
        Parameters:
        to - A string to skip past.
      • skipTo

        public char skipTo​(char to)
        Skip characters until the next character is the requested character. If the requested character is not found, no characters are skipped.
        Parameters:
        to - A character to skip to.
        Returns:
        The requested character, or zero if the requested character is not found.
      • syntaxError

        public JSONException syntaxError​(String message)
        Make a JSONException to signal a syntax error.
        Parameters:
        message - The error message.
        Returns:
        A JSONException object, suitable for throwing
      • toString

        public String toString()
        Make a printable string of this JSONTokener.
        Overrides:
        toString in class Object
        Returns:
        " at character [this.myIndex] of [this.mySource]"
      • reloadLegacyNumberCoercionCompatibility

        public static void reloadLegacyNumberCoercionCompatibility()
        Reloads the numeric compatibility flag from the current system property value. This is mainly useful in tests that toggle the property at runtime.