lineends.java

java操作excel的类

	public final static int STYLE_N = 2;
	/**
	 * The UNIX and Java line ending ("\n")
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public final static int STYLE_JAVA = 2;
	/**
	 * The Macintosh line ending ("\r")
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public final static int STYLE_MAC = 3;
	/**
	 * The Macintosh line ending ("\r")
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public final static int STYLE_R = 3;

	/**
	 * Buffer size when reading from input stream.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	private final static int BUFFER_SIZE = 1024;
	private final static int STATE_INIT = 0;
	private final static int STATE_R = 1;

	private final static int MASK_N = 0x01;
	private final static int MASK_R = 0x02;
	private final static int MASK_RN = 0x04;

	/**
	 * Change the line endings of the text on the input stream and write
	 * it to the output stream.
	 *
	 * The current system's line separator is used.
	 *
	 * @param in stream that contains the text which needs line number conversion.
	 * @param out stream where converted text is written.
	 * @return true if the output was modified from the input, false if it is exactly the same
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(InputStream in, OutputStream out) throws IOException {
		return convert(in, out, STYLE_SYSTEM, true);
	}

	/**
	 * Change the line endings of the text on the input stream and write
	 * it to the output stream.
	 *
	 * @param in stream that contains the text which needs line number conversion.
	 * @param out stream where converted text is written.
	 * @param style line separator style.
	 * @return true if the output was modified from the input, false if it is exactly the same
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 * @throws IllegalArgumentException if an unknown style is requested.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(InputStream in, OutputStream out, int style) throws IOException {
		return convert(in, out, style, true);
	}

	/**
	 * Change the line endings of the text on the input stream and write
	 * it to the output stream.
	 *
	 * The current system's line separator is used.
	 *
	 * @param in stream that contains the text which needs line number conversion.
	 * @param out stream where converted text is written.
	 * @param binaryException throw an exception and abort the operation if binary data is encountered and binaryExcepion is false.
	 * @return true if the output was modified from the input, false if it is exactly the same
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(InputStream in, OutputStream out, boolean binaryException) throws IOException {
		return convert(in, out, STYLE_SYSTEM, binaryException);
	}

	/**
	 * Change the line endings of the text on the input stream and write
	 * it to the output stream.
	 *
	 * @param in stream that contains the text which needs line number conversion.
	 * @param out stream where converted text is written.
	 * @param style line separator style.
	 * @param binaryException throw an exception and abort the operation if binary data is encountered and binaryExcepion is false.
	 * @return true if the output was modified from the input, false if it is exactly the same
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 * @throws IllegalArgumentException if an unknown style is requested.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(InputStream in, OutputStream out, int style, boolean binaryException) throws IOException {
		byte[] lineEnding;
		switch (style) {
			case STYLE_SYSTEM: {
				 lineEnding = System.getProperty("line.separator").getBytes();
			} break;
			case STYLE_RN: {
				 lineEnding = new byte[]{(byte)'\r',(byte)'\n'};
			} break;
			case STYLE_R: {
				 lineEnding = new byte[]{(byte)'\r'};
			} break;
			case STYLE_N: {
				 lineEnding = new byte[]{(byte)'\n'};
			} break;
			default: {
				throw new IllegalArgumentException("Unknown line break style: " + style);
			}
		}
		byte[] buffer = new byte[BUFFER_SIZE];
		int read;
		int state = STATE_INIT;
		int seen = 0x00;
		while((read = in.read(buffer)) != -1){
			for (int i=0; i<read; i++){
				byte b = buffer[i];
				if (state==STATE_R){
					if(b!='\n'){
						out.write(lineEnding);
						seen |= MASK_R;
					}
				}
				if (b=='\r'){
					state = STATE_R;
				} else {
					if (b=='\n'){
						if (state==STATE_R){
							seen |= MASK_RN;
						} else {
							seen |= MASK_N;
						}
						out.write(lineEnding);
					} else if(binaryException && b!='\t' && b!='\f' && (b & 0xff)<32){
						throw new BinaryDataException(labels.getString("binaryexcepion"));
					} else {
						out.write(b);
					}
					state = STATE_INIT;
				}
			}
		}
		if (state==STATE_R){
			out.write(lineEnding);
			seen |= MASK_R;
		}
		if (lineEnding.length==2 && lineEnding[0]=='\r' && lineEnding[1]=='\n'){
			return ((seen & ~MASK_RN)!=0);
		} else if (lineEnding.length==1 && lineEnding[0]=='\r'){
			return ((seen & ~MASK_R)!=0);
		} else if (lineEnding.length==1 && lineEnding[0]=='\n'){
			return ((seen & ~MASK_N)!=0);
		} else {
			return true;
		}
	}

	/**
	 * Change the line endings on given file.
	 *
	 * The current system's line separator is used.
	 *
	 * @param f File to be converted.
	 * @return true if the file was modified, false if it was already in the correct format
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(File f) throws IOException {
		return convert(f, STYLE_SYSTEM, true);
	}

	/**
	 * Change the line endings on given file.
	 *
	 * @param f File to be converted.
	 * @param style line separator style.
	 * @return true if the file was modified, false if it was already in the correct format
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 * @throws IllegalArgumentException if an unknown style is requested.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(File f, int style) throws IOException {
		return convert(f, style, true);
	}

	/**
	 * Change the line endings on given file.
	 *
	 * The current system's line separator is used.
	 *
	 * @param f File to be converted.
	 * @param binaryException throw an exception and abort the operation if binary data is encountered and binaryExcepion is false.
	 * @return true if the file was modified, false if it was already in the correct format
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(File f, boolean binaryException) throws IOException {
		return convert(f, STYLE_SYSTEM, binaryException);
	}

	/**
	 * Change the line endings on given file.
	 *
	 * @param f File to be converted.
	 * @param style line separator style.
	 * @param binaryException throw an exception and abort the operation if binary data is encountered and binaryExcepion is false.
	 * @return true if the file was modified, false if it was already in the correct format
	 * @throws BinaryDataException if non-text data is encountered.
	 * @throws IOException if an input or output error occurs.
	 * @throws IllegalArgumentException if an unknown style is requested.
	 *
	 * @since ostermillerutils 1.00.00
	 */
	public static boolean convert(File f, int style, boolean binaryException) throws IOException {
		File temp = null;
		InputStream in = null;
		OutputStream out = null;
		boolean modified = false;
		try {
			in = new FileInputStream(f);
			temp = File.createTempFile("LineEnds", null, null);
			out = new FileOutputStream(temp);
			modified = convert (in, out, style, binaryException);
			in.close();
			in = null;
			out.flush();
			out.close();
			out = null;
			if (modified){
				FileHelper.move(temp, f, true);
			} else {
				if (!temp.delete()){
					throw new IOException(
						MessageFormat.format(
							labels.getString("tempdeleteerror"),
							new String[] {temp.toString()}
						)
					);
				}
			}
		} finally {
			if (in != null){
				in.close();
				in = null;
			}
			if (out != null){
				out.flush();
				out.close();
				out = null;
			}
		}
		return modified;
	}
}