java实现两个文件的拼接

import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class Append {  static int count=0;  static int countb=0;  public static void main(String args[]) throws IOException  {     FileInputStream filea = new FileInputStream("d://JavaXor//a");     FileInputStream fileb = new FileInputStream("d://JavaXor//b");     File outfile=new File("d://JavaXor//outfile");     int filesizea=filea.available();//计算文件的大小     int filesizeb=fileb.available();     FileOutputStream fos=new FileOutputStream(outfile);     int hasReada = 0;     int hasReadb=0;     byte[] bufa=new byte[1024];     byte[] bufc=new byte[1024];     byte[] buf_yua=new byte[filesizea%1024];     byte[] buf_yub=new byte[filesizeb%1024];     while( (hasReada=filea.read(bufa) )>0 )      {      if(count<filesizea-filesizea%1024)      {          for(int i=0;i<bufa.length && count<filesizea-filesizea%1024;i++)         {          bufc[i]=(byte)(bufa[i] & 0xFF);          count++;         }        fos.write(bufc);      }      else if(count>=filesizea-filesizea%1024 && count<filesizea)      {        for(int j=0; count>=filesizea-filesizea%1024 && count<filesizea ;j++)        {          buf_yua[j]=(byte)(bufa[j] & 0xFF);          count++;        }        fos.write(buf_yua);      }      }     while( (hasReadb=fileb.read(bufa) )>0 )      {      if(countb<filesizeb-filesizeb%1024)      {          for(int i=0;i<bufa.length && countb<filesizeb-filesizeb%1024;i++)         {          bufc[i]=(byte)(bufa[i] & 0xFF);          countb++;         }        fos.write(bufc);      }      else if(countb>=filesizeb-filesizeb%1024 && countb<filesizeb)      {        for(int j=0; countb>=filesizeb-filesizeb%1024 && countb<filesizeb ;j++)        {          buf_yub[j]=(byte)(bufa[j] & 0xFF);          countb++;        }        fos.write(buf_yub);      }      }   }}