org.apache.juneau.parser

Class ParserReader

java.lang.Object

java.io.Reader

org.apache.juneau.parser.ParserReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

Direct Known Subclasses:

UonReader

public class ParserReader
extends Reader

Similar to a PushbackReader with a pushback buffer of 1 character.

Code is optimized to work with a 1 character buffer.

Additionally keeps track of current line and column number, and provides the ability to set mark points and capture characters from the previous mark point.

Warning: Not thread safe.

Field Summary

Fields

Modifier and Type	Field and Description
protected Reader	r Wrapped reader

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor and Description
ParserReader(ParserPipe pipe) Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() No-op.
ParserReader	delete() Trims off the last character in the marking buffer.
ParserReader	delete(int count) Trims off the specified number of last characters in the marking buffer.
int	getColumn() Returns the current column number position in this reader.
int	getLine() Returns the current line number position in this reader.
ObjectMap	getLocation(ParserSession session) Returns the combined location information on both this reader and the session.
String	getMarked() Returns the contents of the reusable character buffer as a string, and resets the buffer for next usage.
String	getMarked(int offsetStart, int offsetEnd) Same as getMarked() except allows you to specify offsets into the buffer.
ParserPipe	getPipe() Returns the pipe that was passed into the constructor.
void	mark() Start buffering the calls to read() so that the text can be gathered from the mark point on calling getFromMarked().
int	peek() Peeks the next character in the stream.
int	peekSkipWs() Same as peek() but skips over any whitespace characters.
int	read() Reads a single character.
int	read(char[] cbuf, int off, int len) Subclasses can override this method to provide additional filtering.
String	read(int num) Read the specified number of characters off the stream.
int	readCodePoint() Same as read() but detects and combines extended unicode characters (i.e.
int	readSkipWs() Same as read() but skips over any whitespace characters.
ParserReader	replace(char c) Replace the last read character in the buffer with the specified character.
ParserReader	replace(int c, int offset) Replaces the last character in the marking buffer with the specified character.
ParserReader	unread() Pushes the last read character back into the stream.

Methods inherited from class java.io.Reader

mark, markSupported, read, read, ready, reset, skip

Methods inherited from class java.lang.Object

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

Field Detail

r

protected final Reader r

Wrapped reader

Constructor Detail

ParserReader

public ParserReader(ParserPipe pipe)
             throws IOException

Constructor.

Parameters:

pipe - The parser input.

Throws:

IOException

Method Detail

getLine

public final int getLine()

Returns the current line number position in this reader.

Returns:

The current line number.

getColumn

public final int getColumn()

Returns the current column number position in this reader.

Returns:

The current column number.

read

public final int read()
               throws IOException

Reads a single character.

Note that this method does NOT process extended unicode characters (i.e. characters above 0x10000), but rather returns them as two chars. Use readCodePoint() to ensure proper handling of extended unicode.

Overrides:

read in class Reader

Returns:

The character read, or -1 if the end of the stream has been reached.

Throws:

IOException - If a problem occurred trying to read from the reader.

readSkipWs

public final int readSkipWs()
                     throws IOException

Same as read() but skips over any whitespace characters.

Returns:

The first non-whitespace character, or -1 if the end of stream reached.

Throws:

IOException

readCodePoint

public final int readCodePoint()
                        throws IOException

Same as read() but detects and combines extended unicode characters (i.e. characters above 0x10000).

Returns:

The character read, or -1 if the end of the stream has been reached.

Throws:

IOException - If a problem occurred trying to read from the reader.

mark

public final void mark()

Start buffering the calls to read() so that the text can be gathered from the mark point on calling getFromMarked().

peek

public final int peek()
               throws IOException

Peeks the next character in the stream.

This is equivalent to doing a read() followed by an unread().

Returns:

The peeked character, or (char)-1 if the end of the stream has been reached.

Throws:

IOException - If a problem occurred trying to read from the reader.

peekSkipWs

public final int peekSkipWs()
                     throws IOException

Same as peek() but skips over any whitespace characters.

This is equivalent to doing a read() followed by an unread().

Returns:

The peeked character, or (char)-1 if the end of the stream has been reached.

Throws:

IOException - If a problem occurred trying to read from the reader.

read

public final String read(int num)
                  throws IOException

Read the specified number of characters off the stream.

Parameters:

num - The number of characters to read.

Returns:

The characters packaged as a String.

Throws:

IOException - If a problem occurred trying to read from the reader.

unread

public ParserReader unread()
                    throws IOException

Pushes the last read character back into the stream.

Returns:

This object (for method chaining).

Throws:

IOException - If a problem occurred trying to read from the reader.

close

public void close()
           throws IOException

No-op.

Input readers are closed in the ParserPipe class.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Reader

Throws:

IOException - If a problem occurred trying to read from the reader.

getMarked

public final String getMarked()

Returns the contents of the reusable character buffer as a string, and resets the buffer for next usage.

Returns:

The contents of the reusable character buffer as a string.

getMarked

public final String getMarked(int offsetStart,
                              int offsetEnd)

Same as getMarked() except allows you to specify offsets into the buffer.

For example, to return the marked string, but trim the first and last characters, call the following:

getFromMarked(1, -1);

Parameters:

offsetStart - The offset of the start position.

offsetEnd - The offset of the end position.

Returns:

The contents of the reusable character buffer as a string.

delete

public final ParserReader delete()

Trims off the last character in the marking buffer.

Useful for removing escape characters from sequences.

Returns:

This object (for method chaining).

delete

public final ParserReader delete(int count)

Trims off the specified number of last characters in the marking buffer. Useful for removing escape characters from sequences.

Parameters:

count - The number of characters to delete.

Returns:

This object (for method chaining).

replace

public final ParserReader replace(int c,
                                  int offset)
                           throws IOException

Replaces the last character in the marking buffer with the specified character.

offset must be at least 1 for normal characters, and 2 for extended unicode characters in order for the replacement to fit into the buffer.

Parameters:

c - The new character.

offset - The offset.

Returns:

This object (for method chaining).

Throws:

IOException

replace

public final ParserReader replace(char c)
                           throws IOException

Replace the last read character in the buffer with the specified character.

Parameters:

c - The new character.

Returns:

This object (for method chaining).

Throws:

IOException

read

public int read(char[] cbuf,
                int off,
                int len)
         throws IOException

Subclasses can override this method to provide additional filtering.

Default implementation simply calls the same method on the underlying reader.

Specified by:

read in class Reader

Throws:

IOException

getLocation

public ObjectMap getLocation(ParserSession session)

Returns the combined location information on both this reader and the session.

Parameters:

session - The session object to read the last location on.

Returns:

A new map describing the current parse location.

getPipe

public final ParserPipe getPipe()

Returns the pipe that was passed into the constructor.

Returns:

The pipe that was passed into the constructor.