Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2 only ("GPL") or the Common Development * and Distribution License("CDDL") (collectively, the "License"). You * may not use this file except in compliance with the License. You can obtain * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific * language governing permissions and limitations under the License. * * When distributing the software, include this License Header Notice in each * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt. * Sun designates this particular file as subject to the "Classpath" exception * as provided by Sun in the GPL Version 2 section of the License file that * accompanied this code. If applicable, add the following below the License * Header, with the fields enclosed by brackets [] replaced by your own * identifying information: "Portions Copyrighted [year] * [name of copyright owner]" * * Contributor(s): * * If you wish your version of this file to be governed by only the CDDL or * only the GPL Version 2, indicate your decision by adding "[Contributor] * elects to include this software in this distribution under the [CDDL or GPL * Version 2] license." If you don't indicate a single choice of license, a * recipient has the option to distribute your version of this file under * either the CDDL, the GPL Version 2 or to extend the choice of license to * its licensees as provided above. However, if you add GPL Version 2 code * and therefore, elected the GPL Version 2 license, then the option applies * only if the new code is made subject to such option by the copyright * holder. */ /* * @(#)TraceInputStream.java 1.8 07/05/04 */ import java.io.*; /** * This class is a FilterInputStream that writes the bytes * being read from the given input stream into the given output * stream. This class is typically used to provide a trace of * the data that is being retrieved from an input stream. * * @author John Mani */ public class TraceInputStream extends FilterInputStream { private boolean trace = false; private boolean quote = false; private OutputStream traceOut; /** * Creates an input stream filter built on top of the specified * input stream. * * @param in the underlying input stream. * @param out the trace stream */ public TraceInputStream(InputStream in, OutputStream traceOut) { super(in); this.traceOut = traceOut; } /** * Set trace mode. * @param trace the trace mode */ public void setTrace(boolean trace) { this.trace = trace; } /** * Set quote mode. * @param quote the quote mode */ public void setQuote(boolean quote) { this.quote = quote; } /** * Reads the next byte of data from this input stream. Returns * <code>-1</code> if no data is available. Writes out the read * byte into the trace stream, if trace mode is <code>true</code> */ public int read() throws IOException { int b = in.read(); if (trace && b != -1) { if (quote) writeByte(b); else traceOut.write(b); } return b; } /** * Reads up to <code>len</code> bytes of data from this input stream * into an array of bytes. Returns <code>-1</code> if no more data * is available. Writes out the read bytes into the trace stream, if * trace mode is <code>true</code> */ public int read(byte b[], int off, int len) throws IOException { int count = in.read(b, off, len); if (trace && count != -1) { if (quote) { for (int i = 0; i < count; i++) writeByte(b[off + i]); } else traceOut.write(b, off, count); } return count; } /** * Write a byte in a way that every byte value is printable ASCII. */ private final void writeByte(int b) throws IOException { b &= 0xff; if (b > 0x7f) { traceOut.write('M'); traceOut.write('-'); b &= 0x7f; } if (b == '\r') { traceOut.write('\\'); traceOut.write('r'); } else if (b == '\n') { traceOut.write('\\'); traceOut.write('n'); traceOut.write('\n'); } else if (b == '\t') { traceOut.write('\\'); traceOut.write('t'); } else if (b < ' ') { traceOut.write('^'); traceOut.write('@' + b); } else { traceOut.write(b); } } }