/*
* 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.sling.mailarchiveserver.util;
/**
* Util class to log System.err and System.out streams.
*
* taken from http://stackoverflow.com/questions/11187461/redirect-system-out-and-system-err-to-slf4j
* @author itshorty
*/
import java.io.IOException;
import java.io.PrintStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SysStreamsLogger {
private static Logger sysOutLogger = LoggerFactory.getLogger("SYSOUT");
private static Logger sysErrLogger = LoggerFactory.getLogger("SYSERR");
public static final PrintStream sysout = System.out;
public static final PrintStream syserr = System.err;
protected static final String LINE_SEPERATOR = System.getProperty("line.separator");
public static void bindSystemStreams() {
// Enable autoflush
System.setOut(new PrintStream(new LoggingOutputStream(sysOutLogger, false), true));
System.setErr(new PrintStream(new LoggingOutputStream(sysErrLogger, true), true));
}
public static void unbindSystemStreams() {
System.setOut(sysout);
System.setErr(syserr);
}
private static class LoggingOutputStream extends java.io.OutputStream {
protected Logger log;
protected boolean isError;
/**
* Used to maintain the contract of {@link #close()}.
*/
protected boolean hasBeenClosed = false;
/**
* The internal buffer where data is stored.
*/
protected byte[] buf;
/**
* The number of valid bytes in the buffer. This value is always in the
* range <tt>0</tt> through <tt>buf.length</tt>; elements
* <tt>buf[0]</tt> through <tt>buf[count-1]</tt> contain valid byte
* data.
*/
protected int count;
/**
* Remembers the size of the buffer for speed.
*/
private int bufLength;
/**
* The default number of bytes in the buffer. =2048
*/
public static final int DEFAULT_BUFFER_LENGTH = 2048;
private LoggingOutputStream() {
// illegal
}
/**
* Creates the LoggingOutputStream to flush to the given Category.
*
* @param log
* the Logger to write to
*
* @param isError
* the if true write to error, else info
*
* @exception IllegalArgumentException
* if cat == null or priority == null
*/
public LoggingOutputStream(Logger log, boolean isError) throws IllegalArgumentException {
if (log == null) {
throw new IllegalArgumentException("log == null");
}
this.isError = isError;
this.log = log;
bufLength = DEFAULT_BUFFER_LENGTH;
buf = new byte[DEFAULT_BUFFER_LENGTH];
count = 0;
}
/**
* Closes this output stream and releases any system resources
* associated with this stream. The general contract of
* <code>close</code> is that it closes the output stream. A closed
* stream cannot perform output operations and cannot be reopened.
*/
@Override
public void close() {
flush();
hasBeenClosed = true;
}
/**
* Writes the specified byte to this output stream. The general contract
* for <code>write</code> is that one byte is written to the output
* stream. The byte to be written is the eight low-order bits of the
* argument <code>b</code>. The 24 high-order bits of <code>b</code> are
* ignored.
*
* @param b
* the <code>byte</code> to write
*/
@Override
public void write(final int b) throws IOException {
if (hasBeenClosed) {
throw new IOException("The stream has been closed.");
}
// don't log nulls
if (b == 0) {
return;
}
// would this be writing past the buffer?
if (count == bufLength) {
// grow the buffer
final int newBufLength = bufLength + DEFAULT_BUFFER_LENGTH;
final byte[] newBuf = new byte[newBufLength];
System.arraycopy(buf, 0, newBuf, 0, bufLength);
buf = newBuf;
bufLength = newBufLength;
}
buf[count] = (byte) b;
count++;
}
/**
* Flushes this output stream and forces any buffered output bytes to be
* written out. The general contract of <code>flush</code> is that
* calling it is an indication that, if any bytes previously written
* have been buffered by the implementation of the output stream, such
* bytes should immediately be written to their intended destination.
*/
@Override
public void flush() {
if (count == 0) {
return;
}
// don't print out blank lines; flushing from PrintStream puts out
// these
if (count == LINE_SEPERATOR.length()) {
if (((char) buf[0]) == LINE_SEPERATOR.charAt(0) && ((count == 1) || // <-
// Unix
// &
// Mac,
// ->
// Windows
((count == 2) && ((char) buf[1]) == LINE_SEPERATOR.charAt(1)))) {
reset();
return;
}
}
final byte[] theBytes = new byte[count];
System.arraycopy(buf, 0, theBytes, 0, count);
if (isError) {
log.error(new String(theBytes));
} else {
log.info(new String(theBytes));
}
reset();
}
private void reset() {
// not resetting the buffer -- assuming that if it grew that it
// will likely grow similarly again
count = 0;
}
}
}