logwriter.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Infozone Software License version 2 published by the Infozone Group
// (http://www.infozone-group.org).
//
// Copyright (C) @year@ by The Infozone Group. All rights reserved.
//
// $Id: LogWriter.java,v 1.1 2002/05/10 08:59:12 per_nyfelt Exp $

package org.infozone.tools.logger;

import java.io.*;
import java.util.*;


/**
@author <a href="http://www.softwarebuero.de/">SMB</a>
@version $Revision: 1.1 $Date: 2002/05/10 08:59:12 $
*/
public final class LogWriter {

    public static final int		INFO	= 1;
    public static final int		WARN	= 2;
    public static final int		ERROR	= 4;
    public static final int		DEBUG	= 8;
    public static final int		DEBUG2	= 16;
    public static final int		DEBUG3	= 32;

    protected static final String	INFO_PREFIX	= "[info] ";
    protected static final String	WARN_PREFIX	= "[warn] ";
    protected static final String	ERROR_PREFIX	= "[error]";
    protected static final String	DEBUG_PREFIX	= "[debug]";

    public static final int	LINE_WIDTH = 70;

    protected Vector		logTargets;

    protected int		allLevels;


    public LogWriter() {
        logTargets = new Vector();
        }


    /**
    This method allows to quickly find out if there is any log target that
    would receive entries of the specified level.
    */
    public boolean hasTarget (int level) {
        return (allLevels & level) > 0;
        }


    public void addLogTarget (OutputStream _out, int _levels) {
        // set also lower debug levels when higher levels are requested
        _levels = ((_levels & DEBUG3) > 0) ? (_levels | DEBUG2) : _levels;
        _levels = ((_levels & DEBUG2) > 0) ? (_levels | DEBUG) : _levels;

        addLogTarget (new PrintWriter (_out), _levels);
        }


    public void addLogTarget (PrintWriter _writer, int _levels) {
        // set also lower debug levels when higher levels are requested
        _levels = ((_levels & DEBUG3) > 0) ? (_levels | DEBUG2) : _levels;
        _levels = ((_levels & DEBUG2) > 0) ? (_levels | DEBUG) : _levels;

        logTargets.addElement (new LogTarget (_writer, _levels));
        allLevels = allLevels | _levels;
        }


    public void newEntry (Object sender, String msg, int levels) {
        newEntry (sender, msg, null, levels);
        }


    public void newEntry (Object sender, String msg, Throwable e, int levels) {
        //check if at least one of the specified levels is supported by
        //any of the LogTargets
        if ((allLevels & levels) > 0) {
            for (int i=0; i<logTargets.size(); i++) {
                LogTarget logTarget = (LogTarget)logTargets.elementAt (i);
                if ((logTarget.levels & levels & INFO) > 0)
                    printToWriter (logTarget.writer, sender, msg, INFO_PREFIX, e);
                if ((logTarget.levels & levels & WARN) > 0)
                    printToWriter (logTarget.writer, sender, msg, WARN_PREFIX, e);
                if ((logTarget.levels & levels & ERROR) > 0)
                    printToWriter (logTarget.writer, sender, msg, ERROR_PREFIX, e);
                if ((logTarget.levels & levels & (DEBUG | DEBUG2 | DEBUG3)) > 0)
                    printToWriter (logTarget.writer, sender, msg, DEBUG_PREFIX, e);
                }
            }
        }


    protected void printToWriter (PrintWriter writer, Object sender, String msg, String status, Throwable e) {
        StringBuffer sb = new StringBuffer (120);
        sb.append (status);
        sb.append ('(');
        String threadNum = String.valueOf(Thread.currentThread().hashCode());
        sb.append (threadNum.substring (threadNum.length() - 3));
        sb.append (") ");
        sb.append (rawClassName (sender));
        sb.append (": ");
        sb.append (msg);
        writer.println (sb);
        writer.flush();
        if (e != null) {
           // writer.print ("    exception: " + e.getUserName());
            printFormatedException (writer, e, LINE_WIDTH, "    ");
            }
        }


    public static String rawClassName (Object obj) {
        if (obj != null) {
            String name = (obj instanceof Class)
                ?((Class)obj).getName()
                :obj.getClass().getName();
            int index = name.lastIndexOf('.');
            return name.substring (index+1);
            }
        else
            return "(null)";
        }


    protected void printFormatedException (OutputStream out, Throwable e, int lineWidth, String pre) {
        printFormatedException (new PrintWriter (out), e, lineWidth, pre);
        }


    protected void printFormatedException (PrintWriter out, Throwable e, int lineWidth, String pre) {
        StringWriter buff = new StringWriter();
        e.printStackTrace (new PrintWriter (buff));
        StringTokenizer st = new StringTokenizer (buff.toString(), "\n");
        while (st.hasMoreTokens()) {
            String line = st.nextToken();
            boolean firstSubLine = true;
           // while (line.length() > lineWidth) {
            do {
                int subLineLength = Math.min (lineWidth, line.length());
                String subLine = line.substring (0, subLineLength);
                line = line.substring (subLineLength);
                if (!firstSubLine)
                    out.print ("        ");
                out.print (pre);
                out.println (subLine);
                firstSubLine = false;
                }
            while (line.length() > 0);
            }
        out.flush();
        }

    }