simplelogwriter.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 Ozone Library License version 1 published by ozone-db.org.
//
// Copyright (C) 1997-@year@ by Per Nyfelt. All rights reserved.
//
// $Id: LogWriter.java,v 1.5 2002/12/29 11:15:58 per_nyfelt Exp $
package org.ozoneDB.util;

import java.io.Serializable;

/**
 * Provides simple console logging
 * Usage: LogWriter logWriter = SimpleLogWriter.getInstance().setDebugLevel(LogWriter.DEBUG);
 * @author Per Nyfelt
 */
public class SimpleLogWriter implements LogWriter, Serializable {

    private int debugLevel;
    private static SimpleLogWriter instance;


    public synchronized static SimpleLogWriter getInstance(){
        if(instance == null){
            instance = new SimpleLogWriter();
        }
        return instance;
    }

    public SimpleLogWriter setDebugLevel(int debugLevel) {
        this.debugLevel = debugLevel;
        return this;
    }

    private SimpleLogWriter() {

    }

    /**
     * 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 level <= debugLevel;
    }

    public void newEntry(Object sender, String msg, int level) {
        if (hasTarget(level)) {
            System.out.println("[" + sender.getClass().getName() + "] " + msg);
        }
    }

    public void newEntry(Object sender, String msg, Throwable e, int level) {
        if (hasTarget(level)) {
            System.out.println("[" + sender.getClass().getName() + "] "
                    + msg
                    + ", "
                    + e.toString());
        }
    }
}