File	Doc	Category	Size	Date	Package
Gen_Reader.java	API Doc	J2ME MIDP 2.0	9426	Thu Nov 07 12:02:20 GMT 2002	com.sun.cldc.i18n.j2me

Gen_Reader

• java.lang.Object
  • StreamReader

Fields Summary
private String	enc Saved encoding string from construction.
private int	id Native handle for conversion routines.
private byte[]	buf Local buffer to read converted characters.
private int	maxByteLen Maximum length of characters in local buffer.
private byte[]	tmp Local buffer for conversion routines.
private int	pos Current position in the temporary buffer.

Constructors Summary

Gen_Reader(String enc) Constructor for generic reader. param enc character encoding to use for byte to character conversion. exception ClassNotFoundException is thrown if the conversion class is not available id = Conv.getHandler(enc); if (id == -1) { // this lets Helper throw UnsupportedEncodingException throw new ClassNotFoundException(); } this.enc = enc; maxByteLen = Conv.getMaxByteLength(id); pos = maxByteLen; tmp = new byte[pos]; buf = new byte[pos];

Methods Summary
private int	get() Get a byte from the temporary buffer or from the input stream. return the next byte from the input stream or local buffer exception IOException is thrown, if an error occured reading the raw input stream if (pos < tmp.length) { return tmp[pos++] & 0xff; } return in.read();
private void	init() reset the state pos = maxByteLen;
public java.io.Reader	open(java.io.InputStream in, java.lang.String enc) Generic routine to open an InputStream with a specific character encoding. param in the input stream to process param enc the character encoding of the input stream return Reader instance for converted characters throws UnsupportedEncodingException if encoding is not supported if (!enc.equals(this.enc)) { throw new UnsupportedEncodingException(); } init(); return super.open(in, enc);
private void	put(int b) Put a byte back into the temporary buffer. param b the character to put back in the temporary buffer exception IOException is thrown, if putting a character back past the beginning of the local temporary buffer if (pos == 0) { throw new IOException(); } tmp[--pos] = (byte) b;
public synchronized int	read() Read a single converted character. return a single converted character exception IOException is thrown if the input stream could not be read for the raw unconverted character int c = get(); if (c == -1) { return -1; } char[] cb = {(char)0xFFFD}; int bufLen = 0; buf[bufLen++] = (byte) c; boolean eof = false; for (int i = 1; i < maxByteLen; i++) { c = get(); if (c == -1) { eof = true; break; } buf[bufLen++] = (byte) c; } int bytelen = Conv.getByteLength(id, buf, 0, bufLen); /* the byte indicates that there are tailing bytes */ if (bytelen == -1) { /* if the stream is in the end, throw IOException */ if (eof) { throw new IOException(/* "incomplete byte" */); } /* put the read ahead bytes back to the stream */ for (int i = bufLen; i > 1; i--) { put(buf[--bufLen]); } /* return the leading byte as an unknown character */ return cb[0]; } /* the byte is invalid */ if (bytelen == 0) { for (int i = bufLen; i > 1; i--) { put(buf[--bufLen]); } return cb[0]; } /* put the read ahead bytes back to the stream */ if (bytelen < bufLen) { for (int i = bufLen; i > bytelen; i--) { put(buf[--bufLen]); } } int convLen = Conv.byteToChar(id, buf, 0, bufLen, cb, 0, 1); if (convLen != 1) { throw new IOException(/*"Converter error"*/); } return cb[0];
public synchronized int	read(char[] cbuf, int off, int len) Read a block of converted characters. param cbuf output buffer for converted characters read param off initial offset into the provided buffer param len length of characters in the buffer return the number of converted characters, or -1 if an error occured in the input arguments exception IOException is thrown if the input stream could not be read for the raw unconverted character /* first, check that the stream has been reached to eof */ int c = get(); if (c == -1) { return -1; } put(c); /* put it back */ int maxlen = len * maxByteLen; if (buf.length < maxlen) { buf = new byte[maxlen]; } int bufLen = readNumOfChars(buf, len); int ret = 0; if (bufLen > 0) { ret = Conv.byteToChar(id, buf, 0, bufLen, cbuf, off, len); } if (buf.length > maxByteLen) { buf = new byte[maxByteLen]; } return ret;
private int	readNumOfChars(byte[] b, int num) Read a specific number of characters from the input stream. param b array of bytes to read param num count of bytes to read return number of characters read exception IOException is thrown, if an error occured reading the raw input stream int charsRead = 0; int bbLen = 0; byte bb[]; if (b == null) { bb = new byte[num * maxByteLen]; } else { bb = b; } boolean eof = false; while (charsRead < num) { int c = get(); if (c == -1) { break; } int offset = bbLen; bb[bbLen++] = (byte) c; for (int i = 1; i < maxByteLen; i++) { c = get(); if (c == -1) { eof = true; break; } bb[bbLen++] = (byte) c; } int readNum = bbLen - offset; int bytelen = Conv.getByteLength(id, bb, offset, readNum); /* the byte indicates that there are tailing bytes */ if (bytelen == -1) { /* save the leading byte for the next read */ if (eof) { for (int i = readNum; i > 0; i--) { put(bb[--bbLen]); } break; } /* put the rest of bytes back into the stream */ for (int i = readNum; i > 1; i--) { put(bb[--bbLen]); } /* the byte is invalid */ } else if (bytelen == 0) { for (int i = readNum; i > 1; i--) { put(bb[--bbLen]); } } else if (bytelen < readNum) { for (int i = readNum; i > bytelen; i--) { put(bb[--bbLen]); } } charsRead++; } if (b != null) { return bbLen; } else { return charsRead; }
public void	reset() Reset the stream. exception IOException If an I/O error occurs init();
public int	sizeOf(byte[] c, int offset, int length) Get the size of the converted bytes as a Unicode byte array. param c array of bytes to compute size param offset offset in the provided buffer param length length of bytes to process return length of converted characters. return Conv.sizeOfByteInUnicode(id, c, offset, length);
public long	skip(long n) Skip over a number of bytes in the input stream. param n number of bytes to bypass from the input stream. return the number of characters skipped throws IOException if an I/O error occurs if (n < 0L) { throw new IllegalArgumentException("skip value is negative"); } /* see the stream has been reached to eof */ int c = get(); if (c == -1) { return 0; } put(c); return readNumOfChars(null, (int) n);