第三方jar包解读文件编码

package test;

//import cpdetector.io.*;
import info.monitorenter.cpdetector.io.CodepageDetectorProxy;
import info.monitorenter.cpdetector.io.JChardetFacade;

import java.io.*;
import java.nio.charset.*;

public class PageCode {
    public static void main(String args[]) {

        CodepageDetectorProxy detector = CodepageDetectorProxy.getInstance();
        detector.add(JChardetFacade.getInstance());

        Charset charset = null;

        File f = new File("D:/test/1.xls");

        try {
            charset = detector.detectCodepage(f.toURL());
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (charset != null) {
            System.out.println(f.getName() + "编码是：" + charset.name());
        } else
            System.out.println(f.getName() + "未知");
    }
}

原理：

import java.io.*;

public class TestText {
    public static void main(String args[]){
        File file = new File("C:/1.txt");

        try{
            InputStream stream = new FileInputStream(file);
            byte[] byteArray = new byte[3];

            stream.read(byteArray);
            stream.close();

            if (byteArray[0] == -17 && byteArray[1] ==  -69 && byteArray[2] == -65)
                System.out.println("UTF-8");
            else
                System.out.println("可能是其他的编码");

        }
        catch(Exception e){
            e.printStackTrace();
        }
    }
}

http://blog.csdn.net/justinavril/archive/2008/08/07/2783266.aspx

jar包下载地址：
http://ncu.dl.sourceforge.net/project/cpdetector/cpdetector/binaries/cpdetector_1.0.7_binary.zip