【正确答案】FilelnputStream用来从文件中读取字节流。FileOutputStream用来向文件中写字节流。使用例子如下：
   import java.io.*;
   public class Test
   {
   public static void main(String[]args)throws IOException
   {
   FileInputStream inputStream=new FileInputStream("Input.txt");
   FileOutputStream outputStream=new FileOutputStream("Output.txt",true);
   byte[]buffer=new byte[2048];
   int bytesRead;
   while((bytesRead=inputStream.read(buffer))!=-1)
   outputStream.write(buffer,0,bytesRead);
   inputStream.close();
   outputStream.close();
   }
   }