/*
* @(#)LogStream.java 1.7 96/12/17
*
* Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
*
* This software is the confidential and proprietary information of Sun
* Microsystems, Inc. ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Sun.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
* SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
* SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
* THIS SOFTWARE OR ITS DERIVATIVES.
*
* CopyrightVersion 1.1_beta
*/
package java.rmi.server;
import java.io.*;
import java.util.*;
/**
* LogStream presents a mechanism for logging errors that are
* of possible interest to those monitoring the system.
*
* @author Ann Wollrath (lots of code stolen from Ken Arnold)
*/
public class LogStream extends PrintStream {
/** table mapping known log names to log stream objects */
private static Hashtable known = new Hashtable(5);
/** default output stream for new logs */
private static PrintStream defaultStream = System.err;
/** log name for this log */
private String name;
/** stream where output of this log is sent to */
private OutputStream logOut;
/** string writer for writing message prefixes to log stream */
private OutputStreamWriter logWriter;
/** string buffer used for constructing log message prefixes */
private StringBuffer buffer = new StringBuffer();
/** stream used for buffering lines */
private ByteArrayOutputStream bufOut;
/**
* Create a new LogStream object. Since this only constructor is
* private, users must have a LogStream created through the "log"
* method.
* @param name string identifying messages from this log
* @out output stream that log messages will be sent to
*/
private LogStream(String name, OutputStream out)
{
super(new ByteArrayOutputStream());
bufOut = (ByteArrayOutputStream) super.out;
this.name = name;
setOutputStream(out);
}
/**
* Return the LogStream identified by the given name. If
* a log corresponding to "name" does not exist, a log using
* the default stream is created.
*/
public static LogStream log(String name) {
LogStream stream;
synchronized (known) {
stream = (LogStream)known.get(name);
if (stream == null) {
stream = new LogStream(name, defaultStream);
}
known.put(name, stream);
}
return stream;
}
/**
* Return the current default stream for new logs.
*/
public static synchronized PrintStream getDefaultStream() {
return defaultStream;
}
/**
* Set the default stream for new logs.
*/
public static synchronized void setDefaultStream(PrintStream newDefault) {
defaultStream = newDefault;
}
/**
* Return the current stream to which output from this log is sent.
*/
public synchronized OutputStream getOutputStream()
{
return logOut;
}
/**
* Set the stream to which output from this log is sent.
*/
public synchronized void setOutputStream(OutputStream out)
{
logOut = out;
// Maintain an OutputStreamWriter with default CharToByteConvertor
// (just like new PrintStream) for writing log message prefixes.
logWriter = new OutputStreamWriter(logOut);
}
/**
* Write a byte of data to the stream. If it is not a newline, then
* the byte is appended to the internal buffer. If it is a newline,
* then the currently buffered line is sent to the log's output
* stream, prefixed with the appropriate logging information.
*/
public void write(int b)
{
if (b == '\n') {
// synchronize on "this" first to avoid potential deadlock
synchronized (this) {
synchronized (logOut) {
// construct prefix for log messages:
buffer.setLength(0);;
buffer.append( // date/time stamp...
(new Date()).toString());
buffer.append(':');
buffer.append(name); // ...log name...
buffer.append(':');
buffer.append(Thread.currentThread().getName());
buffer.append(':'); // ...and thread name
try {
// write prefix through to underlying byte stream
logWriter.write(buffer.toString());
logWriter.flush();
// finally, write the already converted bytes of
// the log message
bufOut.writeTo(logOut);
logOut.write(b);
logOut.flush();
} catch (IOException e) {
setError();
} finally {
bufOut.reset();
}
}
}
}
else
super.write(b);
}
/**
* Write a subarray of bytes. Pass each through write byte method.
*/
public void write(byte b[], int off, int len)
{
if (len < 0)
throw new ArrayIndexOutOfBoundsException(len);
for (int i = 0; i < len; ++ i)
write(b[off + i]);
}
/**
* Return log name as string representation
*/
public String toString()
{
return name;
}
/** constants for logging levels */
public static final int SILENT = 0;
public static final int BRIEF = 10;
public static final int VERBOSE = 20;
/**
* Convert a string name of a logging level to its internal
* integer representation.
*/
public static int parseLevel(String s)
{
if ((s == null) || (s.length() < 1))
return -1;
try {
return Integer.parseInt(s);
} catch (NumberFormatException e) {
}
if (s.length() < 1)
return -1;
if ("SILENT".startsWith(s.toUpperCase()))
return SILENT;
else if ("BRIEF".startsWith(s.toUpperCase()))
return BRIEF;
else if ("VERBOSE".startsWith(s.toUpperCase()))
return VERBOSE;
return -1;
}
}
