Inheritance diagram for javolution.io.UTF8StreamReader:

Collaboration diagram for javolution.io.UTF8StreamReader:

Public Member Functions
	UTF8StreamReader ()

	UTF8StreamReader (int capacity)

UTF8StreamReader	setInput (InputStream inStream)

boolean	ready () throws IOException

void	close () throws IOException

int	read () throws IOException

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

void	read (Appendable dest) throws IOException

void	reset ()

UTF8StreamReader	setInputStream (InputStream inStream)

Private Member Functions
int	read2 () throws IOException

Private Attributes
InputStream	_inputStream

int	_start

int	_end

final byte[]	_bytes

int	_code

int	_moreBytes

Detailed Description

A UTF-8 stream reader.

This reader supports surrogate char pairs (representing characters in the range [U+10000 .. U+10FFFF]). It can also be used to read characters unicodes (31 bits) directly (ref. read()).

Each invocation of one of the read() methods may cause one or more bytes to be read from the underlying byte-input stream. To enable the efficient conversion of bytes to characters, more bytes may be read ahead from the underlying stream than are necessary to satisfy the current read operation.

Instances of this class can be reused for different input streams and can be part of a higher level component (e.g. parser) in order to avoid dynamic buffer allocation when the input source changes. Also wrapping using a java.io.BufferedReader is unnescessary as instances of this class embed their own data buffers.

Note: This reader is unsynchronized and does not test if the UTF-8 encoding is well-formed (e.g. UTF-8 sequences longer than necessary to encode a character).

Author: Jean-Marie Dautelle

Version: 2.0, December 9, 2004

See also: UTF8StreamWriter

Definition at line 44 of file UTF8StreamReader.java.

Constructor & Destructor Documentation

◆ UTF8StreamReader() [1/2]

javolution.io.UTF8StreamReader.UTF8StreamReader ( )

Creates a UTF-8 reader having a byte buffer of moderate capacity (2048).

Definition at line 69 of file UTF8StreamReader.java.

                               {
         _bytes = new byte[2048];
     }

References javolution.io.UTF8StreamReader._bytes.

◆ UTF8StreamReader() [2/2]

javolution.io.UTF8StreamReader.UTF8StreamReader ( int capacity )

Creates a UTF-8 reader having a byte buffer of specified capacity.

Parameters

capacity the capacity of the byte buffer.

Definition at line 78 of file UTF8StreamReader.java.

                                           {
         _bytes = new byte[capacity];
     }

References javolution.io.UTF8StreamReader._bytes.

Member Function Documentation

◆ close()

void javolution.io.UTF8StreamReader.close ( ) throws IOException

Closes and resets this reader for reuse.

Exceptions

IOException if an I/O error occurs.

Definition at line 120 of file UTF8StreamReader.java.

                                            {
         if (_inputStream != null) {
             _inputStream.close();
             reset();
         }
     }

References javolution.io.UTF8StreamReader._inputStream, and javolution.io.UTF8StreamReader.reset().

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◆ read() [1/3]

int javolution.io.UTF8StreamReader.read ( ) throws IOException

Reads a single character. This method will block until a character is available, an I/O error occurs or the end of the stream is reached.

Returns: the 31-bits Unicode of the character read, or -1 if the end of the stream has been reached.

Exceptions

IOException if an I/O error occurs.

Definition at line 135 of file UTF8StreamReader.java.

                                          {
         byte b = _bytes[_start];
         return ((b >= 0) && (_start++ < _end)) ? b : read2();
     }

References javolution.io.UTF8StreamReader._bytes, javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._start, and javolution.io.UTF8StreamReader.read2().

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◆ read() [2/3]

void javolution.io.UTF8StreamReader.read ( Appendable dest ) throws IOException

Reads characters into the specified appendable. This method will block until the end of the stream is reached.

Parameters

dest	the destination buffer.

Exceptions

IOException if an I/O error occurs.

Definition at line 271 of file UTF8StreamReader.java.

                                                          {
         if (_inputStream == null)
             throw new IOException("No input stream or stream closed");
         while (true) {
             if (_start >= _end) { // Fills buffer.
                 _start = 0;
                 _end = _inputStream.read(_bytes, 0, _bytes.length);
                 if (_end <= 0) { // Done.
                     break;
                 }
             }
             byte b = _bytes[_start];
             if (b >= 0) {
                 dest.append((char) b); // Most common case.
                 _start++;
             } else {
                 int code = read2();
                 if (code < 0x10000) {
                     dest.append((char) code);
                 } else if (code <= 0x10ffff) { // Surrogates.
                     dest.append((char) (((code - 0x10000) >> 10) + 0xd800));
                     dest.append((char) (((code - 0x10000) & 0x3ff) + 0xdc00));
                 } else {
                     throw new CharConversionException("Cannot convert U+"
                             + Integer.toHexString(code)
                             + " to char (code greater than U+10FFFF)");
                 }
             }
         }
     }

References javolution.io.UTF8StreamReader._bytes, javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._inputStream, javolution.io.UTF8StreamReader._start, and javolution.io.UTF8StreamReader.read2().

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◆ read() [3/3]

int javolution.io.UTF8StreamReader.read	(	char	cbuf[],
		int	off,
		int	len
	)		throws IOException

Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs or the end of the stream is reached.

Note: Characters between U+10000 and U+10FFFF are represented by surrogate pairs (two char).

Parameters

cbuf	the destination buffer.
off	the offset at which to start storing characters.
len	the maximum number of characters to read

Returns: the number of characters read, or -1 if the end of the stream has been reached

Exceptions

IOException if an I/O error occurs.

Definition at line 222 of file UTF8StreamReader.java.

                                                                       {
         if (_inputStream == null)
             throw new IOException("No input stream or stream closed");
         if (_start >= _end) { // Fills buffer.
             _start = 0;
             _end = _inputStream.read(_bytes, 0, _bytes.length);
             if (_end <= 0) { // Done.
                 return _end;
             }
         }
         final int off_plus_len = off + len;
         for (int i = off; i < off_plus_len;) {
             // assert(_start < _end)
             byte b = _bytes[_start];
             if ((b >= 0) && (++_start < _end)) {
                 cbuf[i++] = (char) b; // Most common case.
             } else if (b < 0) {
                 if (i < off_plus_len - 1) { // Up to two 'char' can be read.
                     int code = read2();
                     if (code < 0x10000) {
                         cbuf[i++] = (char) code;
                     } else if (code <= 0x10ffff) { // Surrogates.
                         cbuf[i++] = (char) (((code - 0x10000) >> 10) + 0xd800);
                         cbuf[i++] = (char) (((code - 0x10000) & 0x3ff) + 0xdc00);
                     } else {
                         throw new CharConversionException("Cannot convert U+"
                                 + Integer.toHexString(code)
                                 + " to char (code greater than U+10FFFF)");
                     }
                     if (_start < _end) {
                         continue;
                     }
                 }
                 return i - off;
             } else { // End of buffer (_start >= _end).
                 cbuf[i++] = (char) b;
                 return i - off;
             }
         }
         return len;
     }

References javolution.io.UTF8StreamReader._bytes, javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._inputStream, javolution.io.UTF8StreamReader._start, and javolution.io.UTF8StreamReader.read2().

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◆ read2()

int javolution.io.UTF8StreamReader.read2 ( ) throws IOException

private

Definition at line 141 of file UTF8StreamReader.java.

                                            {
         if (_start < _end) {
             byte b = _bytes[_start++];
  
             // Decodes UTF-8.
             if ((b >= 0) && (_moreBytes == 0)) {
                 // 0xxxxxxx
                 return b;
             } else if (((b & 0xc0) == 0x80) && (_moreBytes != 0)) {
                 // 10xxxxxx (continuation byte)
                 _code = (_code << 6) | (b & 0x3f); // Adds 6 bits to code.
                 if (--_moreBytes == 0) {
                     return _code;
                 } else {
                     return read2();
                 }
             } else if (((b & 0xe0) == 0xc0) && (_moreBytes == 0)) {
                 // 110xxxxx
                 _code = b & 0x1f;
                 _moreBytes = 1;
                 return read2();
             } else if (((b & 0xf0) == 0xe0) && (_moreBytes == 0)) {
                 // 1110xxxx
                 _code = b & 0x0f;
                 _moreBytes = 2;
                 return read2();
             } else if (((b & 0xf8) == 0xf0) && (_moreBytes == 0)) {
                 // 11110xxx
                 _code = b & 0x07;
                 _moreBytes = 3;
                 return read2();
             } else if (((b & 0xfc) == 0xf8) && (_moreBytes == 0)) {
                 // 111110xx
                 _code = b & 0x03;
                 _moreBytes = 4;
                 return read2();
             } else if (((b & 0xfe) == 0xfc) && (_moreBytes == 0)) {
                 // 1111110x
                 _code = b & 0x01;
                 _moreBytes = 5;
                 return read2();
             } else {
                 throw new CharConversionException("Invalid UTF-8 Encoding");
             }
         } else { // No more bytes in buffer.
             if (_inputStream == null)
                 throw new IOException("No input stream or stream closed");
             _start = 0;
             _end = _inputStream.read(_bytes, 0, _bytes.length);
             if (_end > 0) {
                 return read2(); // Continues.
             } else { // Done.
                 if (_moreBytes == 0) {
                     return -1;
                 } else { // Incomplete sequence.
                     throw new CharConversionException(
                             "Unexpected end of stream");
                 }
             }
         }
     }

References javolution.io.UTF8StreamReader._bytes, javolution.io.UTF8StreamReader._code, javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._inputStream, javolution.io.UTF8StreamReader._moreBytes, and javolution.io.UTF8StreamReader._start.

Referenced by javolution.io.UTF8StreamReader.read().

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◆ ready()

boolean javolution.io.UTF8StreamReader.ready ( ) throws IOException

Indicates if this stream is ready to be read.

Returns: true if the next read() is guaranteed not to block for input; false otherwise.

Exceptions

IOException if an I/O error occurs.

Definition at line 109 of file UTF8StreamReader.java.

                                               {
         if (_inputStream == null)
             throw new IOException("Stream closed");
         return ((_end - _start) > 0) || (_inputStream.available() != 0);
     }

References javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._inputStream, and javolution.io.UTF8StreamReader._start.

◆ reset()

void javolution.io.UTF8StreamReader.reset ( )

Definition at line 302 of file UTF8StreamReader.java.

                         {
         _code = 0;
         _end = 0;
         _inputStream = null;
         _moreBytes = 0;
         _start = 0;
     }

References javolution.io.UTF8StreamReader._code, javolution.io.UTF8StreamReader._end, javolution.io.UTF8StreamReader._inputStream, javolution.io.UTF8StreamReader._moreBytes, and javolution.io.UTF8StreamReader._start.

Referenced by javolution.io.UTF8StreamReader.close(), and javolution.xml.internal.stream.XMLStreamReaderImpl.reset().

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◆ setInput()

UTF8StreamReader javolution.io.UTF8StreamReader.setInput ( InputStream inStream )

Sets the input stream to use for reading until this reader is closed. For example:[code] Reader reader = new UTF8StreamReader().setInput(inStream); [/code] is equivalent but reads twice as fast as [code] Reader reader = new java.io.InputStreamReader(inStream, "UTF-8"); [/code]

Parameters

inStream the input stream.

Returns: this UTF-8 reader.

Exceptions

IllegalStateException if this reader is being reused and it has not been closed or reset.

Definition at line 95 of file UTF8StreamReader.java.

                                                            {
         if (_inputStream != null)
             throw new IllegalStateException("Reader not closed or reset");
         _inputStream = inStream;
         return this;
     }

References javolution.io.UTF8StreamReader._inputStream.

Referenced by javolution.xml.internal.stream.XMLStreamReaderImpl.setInput(), and javolution.io.UTF8StreamReader.setInputStream().

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◆ setInputStream()

UTF8StreamReader javolution.io.UTF8StreamReader.setInputStream ( InputStream inStream )

Deprecated:: Replaced by setInput(InputStream)

Definition at line 313 of file UTF8StreamReader.java.

                                                                  {
         return this.setInput(inStream);
     }

References javolution.io.UTF8StreamReader.setInput().

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Member Data Documentation

◆ _bytes

final byte [] javolution.io.UTF8StreamReader._bytes

private

Holds the bytes buffer.

Definition at line 64 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.read(), javolution.io.UTF8StreamReader.read2(), and javolution.io.UTF8StreamReader.UTF8StreamReader().

◆ _code

int javolution.io.UTF8StreamReader._code

private

Definition at line 203 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.read2(), and javolution.io.UTF8StreamReader.reset().

◆ _end

int javolution.io.UTF8StreamReader._end

private

Holds the end index.

Definition at line 59 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.read(), javolution.io.UTF8StreamReader.read2(), javolution.io.UTF8StreamReader.ready(), and javolution.io.UTF8StreamReader.reset().

◆ _inputStream

InputStream javolution.io.UTF8StreamReader._inputStream

private

Holds the current input stream or null if closed.

Definition at line 49 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.close(), javolution.io.UTF8StreamReader.read(), javolution.io.UTF8StreamReader.read2(), javolution.io.UTF8StreamReader.ready(), javolution.io.UTF8StreamReader.reset(), and javolution.io.UTF8StreamReader.setInput().

◆ _moreBytes

int javolution.io.UTF8StreamReader._moreBytes

private

Definition at line 205 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.read2(), and javolution.io.UTF8StreamReader.reset().

◆ _start

int javolution.io.UTF8StreamReader._start

private

Holds the start index.

Definition at line 54 of file UTF8StreamReader.java.

Referenced by javolution.io.UTF8StreamReader.read(), javolution.io.UTF8StreamReader.read2(), javolution.io.UTF8StreamReader.ready(), and javolution.io.UTF8StreamReader.reset().

The documentation for this class was generated from the following file:

UTF8StreamReader.java

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ UTF8StreamReader() [1/2]

◆ UTF8StreamReader() [2/2]

Member Function Documentation

◆ close()

◆ read() [1/3]

◆ read() [2/3]

◆ read() [3/3]

◆ read2()

◆ ready()

◆ reset()

◆ setInput()

◆ setInputStream()

Member Data Documentation

◆ _bytes

◆ _code

◆ _end

◆ _inputStream

◆ _moreBytes

◆ _start