Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.pdfbox.pdfwriter; import java.io.FilterOutputStream; import java.io.IOException; import java.io.OutputStream; /** * simple output stream with some minor features for generating "pretty" PDF files. * * @author Michael Traut */ public class COSStandardOutputStream extends FilterOutputStream { /** * To be used when 2 byte sequence is enforced. */ public static final byte[] CRLF = { '\r', '\n' }; /** * Line feed character. */ public static final byte[] LF = { '\n' }; /** * standard line separator. */ public static final byte[] EOL = { '\n' }; // current byte position in the output stream private long position = 0; // flag to prevent generating two newlines in sequence private boolean onNewLine = false; /** * Constructor. * * @param out The underlying stream to write to. */ public COSStandardOutputStream(OutputStream out) { super(out); } /** * Constructor. * * @param out The underlying stream to write to. * @param position The current position of output stream. */ public COSStandardOutputStream(OutputStream out, long position) { super(out); this.position = position; } /** * This will get the current position in the stream. * * @return The current position in the stream. */ public long getPos() { return position; } /** * This will tell if we are on a newline. * * @return true If we are on a newline. */ public boolean isOnNewLine() { return onNewLine; } /** * This will set a flag telling if we are on a newline. * * @param newOnNewLine The new value for the onNewLine attribute. */ public void setOnNewLine(boolean newOnNewLine) { onNewLine = newOnNewLine; } /** * This will write some byte to the stream. * * @param b The source byte array. * @param off The offset into the array to start writing. * @param len The number of bytes to write. * * @throws IOException If the underlying stream throws an exception. */ @Override public void write(byte[] b, int off, int len) throws IOException { setOnNewLine(false); out.write(b, off, len); position += len; } /** * This will write a single byte to the stream. * * @param b The byte to write to the stream. * * @throws IOException If there is an error writing to the underlying stream. */ @Override public void write(int b) throws IOException { setOnNewLine(false); out.write(b); position++; } /** * This will write a CRLF to the stream. * * @throws IOException If there is an error writing the data to the stream. */ public void writeCRLF() throws IOException { write(CRLF); } /** * This will write an EOL to the stream. * * @throws IOException If there is an error writing to the stream */ public void writeEOL() throws IOException { if (!isOnNewLine()) { write(EOL); setOnNewLine(true); } } /** * This will write a Linefeed to the stream. * * @throws IOException If there is an error writing to the underlying stream. */ public void writeLF() throws IOException { write(LF); } }