用java 要获得一个文件的编码，是很困难的，在网上找了很久，什么取前几个字节之类来进行判断，都不行，找了好久在网上终于找到一位前辈写的方法，经测试，是完全符合要求的。

package com.mt.qa;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.URL;

/**

*

*  Copyright (C) <2009> 

*

*   This program is free software: you can redistribute it and/or modify

*  it under the terms of the GNU General Public License as published by

*  the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

*  This program is distributed in the hope that it will be useful,

*   but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU General Public License for more details.

*

* EncodingDetect.java

* �Զ���ȡ�ļ��ı���

* @author Billows.Van

* @since Create on 2010-01-27 11:19:00

* @version 1.0

*/

public class EncodingDetect {

public static void main(String[] args) {

String file = "http://s.szmttx.com:81/sp/ds.do?a=&b=1&c=10000&d=1000&e=1&f=13800431500&g=0&h=&i=&j=1&k=46000";

//  String file = "D:\\3.txt";

String encode=getJavaEncode(file);

System.out.println(encode);

readFile(file,encode);

}

/**

* �õ��ļ��ı���

* @param filePath �ļ�·��

* @return �ļ��ı���

*/

public static String getJavaEncode(String filePath){

BytesEncodingDetect s = new BytesEncodingDetect();

String fileCode = BytesEncodingDetect.javaname[s.detectEncoding(new File(filePath))];

return fileCode;

}

public static void readFile(String file, String code) {

BufferedReader fr;

try {

String myCode = code!=null&&!"".equals(code) ? code : "UTF8";

InputStreamReader read = new InputStreamReader(new FileInputStream(

file), myCode);

fr = new BufferedReader(read);    String line = null;    int flag=1;    // ��ȡÿһ�У��������ˣ�line��Ϊ��    while ((line = fr.readLine()) != null && line.trim().length() > 0) {     if(flag==1) {         line=line.substring(1);//ȥ���ļ�ͷ         flag++;        }     // ÿһ�д���һ��Student���