michael@0: /** michael@0: * Copyright (c) 2012, Ben Fortuna michael@0: * All rights reserved. michael@0: * michael@0: * Redistribution and use in source and binary forms, with or without michael@0: * modification, are permitted provided that the following conditions michael@0: * are met: michael@0: * michael@0: * o Redistributions of source code must retain the above copyright michael@0: * notice, this list of conditions and the following disclaimer. michael@0: * michael@0: * o Redistributions in binary form must reproduce the above copyright michael@0: * notice, this list of conditions and the following disclaimer in the michael@0: * documentation and/or other materials provided with the distribution. michael@0: * michael@0: * o Neither the name of Ben Fortuna nor the names of any other contributors michael@0: * may be used to endorse or promote products derived from this software michael@0: * without specific prior written permission. michael@0: * michael@0: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS michael@0: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT michael@0: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR michael@0: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR michael@0: * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, michael@0: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, michael@0: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR michael@0: * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF michael@0: * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING michael@0: * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS michael@0: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. michael@0: */ michael@0: package net.fortuna.ical4j.data; michael@0: michael@0: import java.io.FilterWriter; michael@0: import java.io.IOException; michael@0: import java.io.Writer; michael@0: michael@0: import org.apache.commons.logging.Log; michael@0: import org.apache.commons.logging.LogFactory; michael@0: michael@0: /** michael@0: *
michael@0: * $Id$ [Apr 6, 2004] michael@0: *michael@0: * michael@0: * A writer that performs iCalendar folding as it writes. michael@0: * @author Ben Fortuna michael@0: */ michael@0: public class FoldingWriter extends FilterWriter { michael@0: michael@0: /** michael@0: * reduced to 73 to be consistent with Apple iCal.. michael@0: */ michael@0: public static final int REDUCED_FOLD_LENGTH = 73; michael@0: michael@0: /** michael@0: * Lines of text SHOULD NOT be longer than 75 octets, excluding the line break. michael@0: */ michael@0: public static final int MAX_FOLD_LENGTH = 75; michael@0: michael@0: private static final char[] FOLD_PATTERN = { '\r', '\n', ' ' }; michael@0: michael@0: private final Log log = LogFactory.getLog(FoldingWriter.class); michael@0: michael@0: private int lineLength; michael@0: michael@0: private final int foldLength; michael@0: michael@0: /** michael@0: * @param writer a writer to write output to michael@0: * @param foldLength the maximum line length michael@0: */ michael@0: public FoldingWriter(final Writer writer, final int foldLength) { michael@0: super(writer); michael@0: this.foldLength = Math.min(foldLength, MAX_FOLD_LENGTH); michael@0: } michael@0: michael@0: /** michael@0: * @param writer a writer to write output to michael@0: */ michael@0: public FoldingWriter(final Writer writer) { michael@0: this(writer, REDUCED_FOLD_LENGTH); michael@0: } michael@0: michael@0: /** michael@0: * {@inheritDoc} michael@0: */ michael@0: public final void write(final int c) throws IOException { michael@0: michael@0: /* michael@0: * super.write(c); if (c == '\n') { lineLength = 0; } else { lineLength += 1; } if (lineLength >= FOLD_LENGTH) { michael@0: * super.write(FOLD_PATTERN); } michael@0: */ michael@0: write(new char[] { (char) c }, 0, 1); michael@0: } michael@0: michael@0: /** michael@0: * {@inheritDoc} michael@0: */ michael@0: public final void write(final char[] buffer, final int offset, michael@0: final int length) throws IOException { michael@0: final int maxIndex = offset + length - 1; michael@0: for (int i = offset; i <= maxIndex; i++) { michael@0: michael@0: // debugging.. michael@0: if (log.isTraceEnabled()) { michael@0: log.trace("char [" + buffer[i] + "], line length [" michael@0: + lineLength + "]"); michael@0: } michael@0: michael@0: // check for fold first so we don't unnecessarily fold after michael@0: // no more data.. michael@0: if (lineLength >= foldLength) { michael@0: super.write(FOLD_PATTERN, 0, FOLD_PATTERN.length); michael@0: michael@0: // re-initialise to 1 to account for the space in fold pattern.. michael@0: lineLength = 1; michael@0: } michael@0: michael@0: super.write(buffer[i]); michael@0: michael@0: if (buffer[i] == '\r' || buffer[i] == '\n') { michael@0: lineLength = 0; michael@0: } michael@0: else { michael@0: lineLength += 1; michael@0: } michael@0: } michael@0: } michael@0: michael@0: /** michael@0: * {@inheritDoc} michael@0: */ michael@0: public final void write(final String str, final int off, final int len) michael@0: throws IOException { michael@0: write(str.toCharArray(), off, len); michael@0: } michael@0: michael@0: /* michael@0: * (non-Javadoc) michael@0: * @see java.io.FilterWriter#write(java.lang.String, int, int) public void write(String arg0, int arg1, int arg2) michael@0: * throws IOException { super.write(arg0, arg1, arg2); if (arg0.indexOf('\n') >= 0) { lineLength = 0; } else { michael@0: * lineLength += 1; } fold(); } michael@0: */ michael@0: michael@0: /* michael@0: * (non-Javadoc) michael@0: * @see java.io.Writer#write(java.lang.String) public void write(String arg0) throws IOException { michael@0: * /* if (lineLength + michael@0: * arg0.length() >= FOLD_LENGTH) { super.write(arg0.substring(0,FOLD_LENGTH-lineLength-1)); michael@0: * super.write(FOLD_PATTERN); super.write(arg0.substring(FOLD_LENGTH-lineLength)); } else { super.write(arg0); } if michael@0: * (arg0.indexOf('\n') >= 0) { lineLength = 0; } else { lineLength += 1; } fold(); char[] chars = michael@0: * arg0.toCharArray(); for (int i=0; i