net.yura.mobile.io.json
Class JSONTokener

java.lang.Object
  extended by net.yura.mobile.io.json.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:
2008-09-18
Author:
JSON.org

Constructor Summary
JSONTokener(Reader reader)
          Construct a JSONTokener from a string.
 
Method Summary
 void back()
          Back up one character.
static int dehexchar(char c)
          Get the hex value of a character (base16).
 boolean endArray()
           
 boolean endObject()
           
 boolean more()
          Determine if the source string still contains characters that next() can consume.
 char next()
          Get the next character in the source string.
 char next(char c)
          Consume the next character, and check that it matches a specified character.
 String next(int n)
          Get the next n characters.
 char nextClean()
          Get the next char in the string, skipping whitespace.
 String nextKey()
           
 boolean nextNull()
           
 String nextSimple()
           
 String nextString()
          Return the characters up to the next close quote character.
 String nextTo(char d)
          Get the text up but not including the specified character or the end of line, whichever comes first.
 String nextTo(String delimiters)
          Get the text up but not including one of the specified delimiter characters or the end of line, whichever comes first.
 char skipTo(char to)
          Skip characters until the next character is the requested character.
 void startArray()
           
 void startObject()
           
 IOException syntaxError(String message)
          Make a JSONException to signal a syntax error.
 String toString()
          Make a printable string of this JSONTokener.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

JSONTokener

public JSONTokener(Reader reader)
Construct a JSONTokener from a string.

Parameters:
reader - A reader.
Method Detail

back

public void back()
          throws IOException
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.

Throws:
IOException

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.

endArray

public boolean endArray()
                 throws IOException
Throws:
IOException

endObject

public boolean endObject()
                  throws IOException
Returns:
true for end of object, false for no end
Throws:
IOException

more

public boolean more()
             throws IOException
Determine if the source string still contains characters that next() can consume.

Returns:
true if not yet at the end of the source.
Throws:
IOException

next

public char next()
          throws IOException
Get the next character in the source string.

Returns:
The next character, or 0 if past the end of the source string.
Throws:
IOException

next

public char next(char c)
          throws IOException
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.
IOException

next

public String next(int n)
            throws IOException
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.
IOException

nextClean

public char nextClean()
               throws IOException
Get the next char in the string, skipping whitespace.

Returns:
A character, or 0 if there are no more characters.
Throws:
JSONException
IOException

nextKey

public String nextKey()
               throws IOException
Returns:
null if the object is over and there is no more key
Throws:
IOException

nextNull

public boolean nextNull()
                 throws IOException
Throws:
IOException

nextSimple

public String nextSimple()
                  throws IOException
Throws:
IOException

nextString

public String nextString()
                  throws IOException
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.
IOException

nextTo

public String nextTo(char d)
              throws IOException
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.
Throws:
IOException

nextTo

public String nextTo(String delimiters)
              throws IOException
Get the text up but not including one of the specified delimiter characters or the end of line, whichever comes first.

Parameters:
delimiters - A set of delimiter characters.
Returns:
A string, trimmed.
Throws:
IOException

skipTo

public char skipTo(char to)
            throws IOException
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.
Throws:
IOException

startArray

public void startArray()
                throws IOException
Throws:
IOException

startObject

public void startObject()
                 throws IOException
Throws:
IOException

syntaxError

public IOException 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.index]"