java 自己定义异常，记录日志简单说明！留着以后真接复制

Posted 2020-09-23 zhchoutai

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);
		}
		
			
		
	}
 }