log4j 相关配制说明：http://blog.csdn.net/liangrui1988/article/details/17435139

自己定义异常

package org.rui.ExceptionTest;

public class ExtraFeature {

	//-------使用------

	public static void f()throws MyException

	{

	 System.out.println("MyException from f()");

	 throw new MyException();

	}

	public static void l()throws MyException

	{

	 System.out.println("MyException from l()");

	 throw new MyException("Originated in l()");

	}

	public static void r()throws MyException

	{

	 System.out.println("MyException from r()");

	 throw new MyException("originated(起源) in r()");

	}

	//-------main---------

	public static void main(String[] args)

	{

		try {

			f();

		} catch (MyException e) {

			e.printStackTrace(System.out);

		}

		try {

			l();

		} catch (MyException e) {

			e.printStackTrace(System.err);

		}

		try {

			r();

		} catch (MyException e) {

			e.printStackTrace(System.out);

			System.out.println("getLocalizedMessage: "+e.getLocalizedMessage());

		    //栈轨迹

			for(StackTraceElement ste:e.getStackTrace())

				System.out.println("methodName:"+ste.getMethodName());

		}

	}

}

//自己定义异常---

class MyException  extends Exception

{

	private int x;

	public MyException(){}

	public MyException(String msg){super(msg);}

	public MyException(String msg,int x)

	{

		super(msg);

		this.x=x;

	}

	public int val(){return x;}

	public String getMessge()

	{

		return "Detail Message: "+x+"super.getmessage()";

	}

}

异常与日志 简单说明

package org.rui.ExceptionTest;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.util.logging.Logger;

 public class LoggingExceptions{

	 public static void main(String[] args) {

				try {

					throw new LoggingException();

				} catch (LoggingException e) {

					System.err.print("Caught: "+e);

				}

				try {

					throw new LoggingException();

				} catch (LoggingException e) {

					System.err.print("Caught2: "+e);

				}

	}

 }

 class LoggingException extends Exception{

	private static Logger logger=Logger.getLogger("LoggingException");

	public LoggingException() {

		StringWriter trace=new StringWriter();

		printStackTrace(new PrintWriter(trace));

		logger.severe("severett:"+trace.toString());

	}

}

package org.rui.ExceptionTest;

import java.io.FileNotFoundException;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.util.logging.Logger;

 public class LoggingException2{

	 private static Logger logger=Logger.getLogger("LoggingException");

	 static void LogException(Exception e) {

			StringWriter trace=new StringWriter();

			e.printStackTrace(new PrintWriter(trace));

			logger.severe("severett:"+trace.toString());

	}

	 public static void main(String[] args) {

		 try {

			 throw new NullPointerException();

		} catch (NullPointerException e) {

			LogException(e);

		}

	}

 }