net.yura.mobile.io.json

Class JSONTokener

java.lang.Object

net.yura.mobile.io.json.JSONTokener

public class JSONTokener
extends java.lang.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

Constructors

Constructor and Description
JSONTokener(java.io.Reader reader) Construct a JSONTokener from a string.

Method Summary

Modifier and Type	Method and Description
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.
java.lang.String	next(int n) Get the next n characters.
char	nextClean() Get the next char in the string, skipping whitespace.
java.lang.String	nextKey()
boolean	nextNull()
java.lang.String	nextSimple()
java.lang.String	nextString() Return the characters up to the next close quote character.
java.lang.String	nextTo(char d) Get the text up but not including the specified character or the end of line, whichever comes first.
java.lang.String	nextTo(java.lang.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()
java.io.IOException	syntaxError(java.lang.String message) Make a JSONException to signal a syntax error.
java.lang.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(java.io.Reader reader)

Construct a JSONTokener from a string.

Parameters:

reader - A reader.

Method Detail

back

public void back()
          throws java.io.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:

java.io.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.

startArray

public void startArray()
                throws java.io.IOException

Throws:

java.io.IOException

endArray

public boolean endArray()
                 throws java.io.IOException

Throws:

java.io.IOException

more

public boolean more()
             throws java.io.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:

java.io.IOException

next

public char next()
          throws java.io.IOException

Get the next character in the source string.

Returns:

The next character, or 0 if past the end of the source string.

Throws:

java.io.IOException

next

public char next(char c)
          throws java.io.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.

java.io.IOException

next

public java.lang.String next(int n)
                      throws java.io.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.

java.io.IOException

nextClean

public char nextClean()
               throws java.io.IOException

Get the next char in the string, skipping whitespace.

Returns:

A character, or 0 if there are no more characters.

Throws:

JSONException

java.io.IOException

startObject

public void startObject()
                 throws java.io.IOException

Throws:

java.io.IOException

nextKey

public java.lang.String nextKey()
                         throws java.io.IOException

Returns:

null if the object is over and there is no more key

Throws:

java.io.IOException

nextNull

public boolean nextNull()
                 throws java.io.IOException

Throws:

java.io.IOException

endObject

public boolean endObject()
                  throws java.io.IOException

Returns:

true for end of object, false for no end

Throws:

java.io.IOException

nextSimple

public java.lang.String nextSimple()
                            throws java.io.IOException

Throws:

java.io.IOException

nextString

public java.lang.String nextString()
                            throws java.io.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.

java.io.IOException

nextTo

public java.lang.String nextTo(char d)
                        throws java.io.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:

java.io.IOException

nextTo

public java.lang.String nextTo(java.lang.String delimiters)
                        throws java.io.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:

java.io.IOException

skipTo

public char skipTo(char to)
            throws java.io.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:

java.io.IOException

syntaxError

public java.io.IOException syntaxError(java.lang.String message)

Make a JSONException to signal a syntax error.

Parameters:

message - The error message.

Returns:

A JSONException object, suitable for throwing

toString

public java.lang.String toString()

Make a printable string of this JSONTokener.

Overrides:

toString in class java.lang.Object

Returns:

" at character [this.index]"