baseexception.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.exception;

/**
 * <p>Title: </p>
 * <p>Description: All other application excetions shall extends this base exception</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: eBusiness Inc., All right reserved</p>
 * @author unascribed
 * @version 1.0
 */

import java.io.PrintStream;
import java.io.PrintWriter;

public class BaseException extends Exception
{
    private Exception parent; //Exception that causes this Exception
    private String message;

    public BaseException(String message, Exception e)
    {
        this.message = message;
        this.parent = e;
    }

    public BaseException(Exception e)
    {
        this("", e);
    }

    public BaseException(String message)
    {
        this(message, null);
    }
    //Return latest NON-Blank message
    public String getMessage()
    {
        if (this.message == null || this.message.trim().length() == 0)
        {
            if (this.parent != null)
                return this.parent.getMessage();
            else
                return super.getMessage();
        }
        else
            return this.message;
    }

    //Return the direct Exception that causes this Exception
    public Exception getParentException()
    {
        return this.parent;
    }

    //Prints this exception and its backtrace to the standard error stream
    public void printStackTrace()
    {
        if (this.parent != null)
        {
            System.err.println(this.getClass().getName() + ": " + this.message);
            System.err.println(" CAUSED BY: ");
            this.parent.printStackTrace();
        }
        else
            super.printStackTrace();
    }

    //Prints this exception and its backtrace to the specified print stream
    public void printStackTrace(PrintStream s)
    {
        if (this.parent != null)
        {
            s.println(this.getClass().getName() + ": " + this.message);
            s.println(" CAUSED BY: ");
            this.parent.printStackTrace(s);
        }
        else
            super.printStackTrace();
    }


    //Prints this exception and its backtrace to the specified print writer
    public void printStackTrace(PrintWriter s)
    {
        if (this.parent != null)
        {
            s.println(this.getClass().getName() + ": " + this.message);
            s.println(" CAUSED BY: ");
            this.parent.printStackTrace(s);
        }
        else
            super.printStackTrace();
    }
}