y.io.gml
Class GMLTokenizer

java.lang.Object
  y.io.gml.GMLTokenizer

public class GMLTokenizer
extends Object

This class is used to parse a valid stream from a reader, which contains well formed gml. A callback method must be registered with this class, whose methods will be invoked during the parsing of the stream.

Nested Class Summary

static interface	GMLTokenizer.Callback The interface used for the callback during parsing.
static class	GMLTokenizer.DebugCallback An implementation of the callback which can be used to debug the parser.
static class	GMLTokenizer.EncoderCallback An implementation of the callback, which will call the appropriate methods on an encoder.

Field Summary

protected static int	AMPERSAND The type constant for '&'
protected static int	CLOSE The closing brace type constant ']'
protected static int	COMMENT The type constant for a comment in a gml file
protected static int	DIGIT The type constant for a digit in GML
protected static int	EOF The type constant for the end of file token
protected static int	LETTER The type constant for a letter in GML
protected static int	NEWLINE The type constant for a newline in a gml file
protected static int	OPEN The opening brace type constant '['
protected static int	QUOTE The type constant for '"'
protected static int	UNKNOWN The type constant for anything that cannot be categorized in GML
protected static int	WHITESPACE The type constant for any type of whitespace in GML

Constructor Summary

GMLTokenizer()
Creates a new instance of GMLTokenizer

GMLTokenizer(GMLTokenizer.Callback callback)
Creates a new instance of GMLTokenizer and installs the given callback

Method Summary

protected int	classify(char c) classifies the given character
GMLTokenizer.Callback	getCallback() Getter for property callback.
protected int	lookAhead(PushbackReader reader) takes a look at the next character in the stream and classifies it using one of the constants.
protected void	parse(PushbackReader pbReader) this is the actual parsing method
void	parse(Reader reader) starts the parsing and will fire events to the registered callback
protected void	parseComment(PushbackReader reader) parses a comment whitespace
protected char	parseEntity(PushbackReader reader) parses an entity from a GML "instring"
protected String	parseInString(PushbackReader reader) parses the GML "instring"
protected String	parseKey(PushbackReader reader) parses a key
protected List	parseList(PushbackReader reader) parses a GML list
protected Number	parseNumber(PushbackReader reader) parses a Number (Double or Integer)
protected String	parseString(PushbackReader reader) parses a GML String, i.e. removes the quotes and replaces ISO 8859-1 entities with their corresponding characters.
protected Object	parseValue(PushbackReader reader) parses a value, which might be either a String, or a Number, i.e. either Integer or Double
protected void	parseWhiteSpace(PushbackReader reader) parses whitespace
void	setCallback(GMLTokenizer.Callback callback) Setter for property callback.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

OPEN

protected static final int OPEN

The opening brace type constant '['

See Also:

Constant Field Values

CLOSE

protected static final int CLOSE

The closing brace type constant ']'

See Also:

Constant Field Values

AMPERSAND

protected static final int AMPERSAND

The type constant for '&'

See Also:

Constant Field Values

QUOTE

protected static final int QUOTE

The type constant for '"'

See Also:

Constant Field Values

WHITESPACE

protected static final int WHITESPACE

The type constant for any type of whitespace in GML

See Also:

Constant Field Values

LETTER

protected static final int LETTER

The type constant for a letter in GML

See Also:

Constant Field Values

DIGIT

protected static final int DIGIT

The type constant for a digit in GML

See Also:

Constant Field Values

EOF

protected static final int EOF

The type constant for the end of file token

See Also:

Constant Field Values

NEWLINE

protected static final int NEWLINE

The type constant for a newline in a gml file

See Also:

Constant Field Values

COMMENT

protected static final int COMMENT

The type constant for a comment in a gml file

See Also:

Constant Field Values

UNKNOWN

protected static final int UNKNOWN

The type constant for anything that cannot be categorized in GML

See Also:

Constant Field Values

Constructor Detail

GMLTokenizer

public GMLTokenizer()

Creates a new instance of GMLTokenizer

GMLTokenizer

public GMLTokenizer(GMLTokenizer.Callback callback)

Creates a new instance of GMLTokenizer and installs the given callback

Parameters:

callback - the callback to be used

Method Detail

parse

public void parse(Reader reader)
           throws IOException

starts the parsing and will fire events to the registered callback

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the stream to be parsed

lookAhead

protected int lookAhead(PushbackReader reader)
                 throws IOException

takes a look at the next character in the stream and classifies it using one of the constants.

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader from which to read

Returns:

one of the constants defined in this class

parse

protected void parse(PushbackReader pbReader)
              throws IOException

this is the actual parsing method

Throws:

IOException - in the case of an I/O Exception

Parameters:

pbReader - the reader which will be used to parse the stream

classify

protected int classify(char c)

classifies the given character

Parameters:

c - the character

Returns:

one of the constants defined in this class

parseWhiteSpace

protected void parseWhiteSpace(PushbackReader reader)
                        throws IOException

parses whitespace

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

parseComment

protected void parseComment(PushbackReader reader)
                     throws IOException

parses a comment whitespace

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

parseKey

protected String parseKey(PushbackReader reader)
                   throws IOException

parses a key

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

Returns:

the key

parseValue

protected Object parseValue(PushbackReader reader)
                     throws IOException

parses a value, which might be either a String, or a Number, i.e. either Integer or Double

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

Returns:

a String or a Number

parseNumber

protected Number parseNumber(PushbackReader reader)
                      throws IOException

parses a Number (Double or Integer)

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

Returns:

a Number (Double or Integer)

parseString

protected String parseString(PushbackReader reader)
                      throws IOException

parses a GML String, i.e. removes the quotes and replaces ISO 8859-1 entities with their corresponding characters.

Throws:

IOException - in the case of an I/O Exception

Parameters:

reader - the reader

Returns:

the translated GML "instring"

parseInString

protected String parseInString(PushbackReader reader)
                        throws IOException

parses the GML "instring"

Throws:

IOException

parseEntity

protected char parseEntity(PushbackReader reader)
                    throws IOException

parses an entity from a GML "instring"

Throws:

IOException

parseList

protected List parseList(PushbackReader reader)
                  throws IOException

parses a GML list

Throws:

IOException

getCallback

public GMLTokenizer.Callback getCallback()

Getter for property callback.

Returns:

Value of property callback.

setCallback

public void setCallback(GMLTokenizer.Callback callback)

Setter for property callback.

Parameters:

callback - New value of property callback.