java下io文件合并功能

package cn.stat.p1.file;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Vector;

public class sequendemo {

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        /*这个方法可以用，但是过期了
        Vector<FileInputStream> v=new Vector<FileInputStream>();
        v.add(new FileInputStream("D:\\1.txt"));
        v.add(new FileInputStream("D:\\2.txt"));
        v.add(new FileInputStream("D:\\3.txt"));

        Enumeration<FileInputStream> en=v.elements();
        */

        ArrayList<FileInputStream> al=new ArrayList<FileInputStream>();
        al.add(new FileInputStream("D:\\1.txt"));
        al.add(new FileInputStream("D:\\2.txt"));
        al.add(new FileInputStream("D:\\3.txt"));

        Enumeration<FileInputStream> en=Collections.enumeration(al);
        SequenceInputStream sis=new SequenceInputStream(en);

        FileOutputStream fos=new FileOutputStream("D:\\4.txt");

        byte[] buf=new byte[1024];
        int len=0;
        while((len=sis.read(buf))!=-1)
        {
            fos.write(buf,0,len);
        }

        fos.close();
        sis.close();

    }

}