com.sun.mail.util.TraceInputStream Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.mail.util;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.logging.Level;
/**
* 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 logger log trace here
*/
public TraceInputStream(InputStream in, MailLogger logger) {
super(in);
this.trace = logger.isLoggable(Level.FINEST);
this.traceOut = new LogOutputStream(logger);
}
/**
* Creates an input stream filter built on top of the specified
* input stream.
*
* @param in the underlying input stream.
* @param traceOut 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
* -1 if no data is available. Writes out the read
* byte into the trace stream, if trace mode is true
*/
@Override
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 len bytes of data from this input stream
* into an array of bytes. Returns -1 if no more data
* is available. Writes out the read bytes into the trace stream, if
* trace mode is true
*/
@Override
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);
}
}
}