fileaccess.java

Java网络编程实例第2章实例.rar

package download;

import java.io.*;

/**
 * Title:        Java实现网络文件传输
 * Description:  在客户端请求Web服务器传输指定文件，并将文件保存。
 * Copyright:    Copyright (c) 2002
 * Company:
 * @author 钟华
 * @version 1.0
 */

public class FileAccess implements Serializable{    // 定义访问文件类

  RandomAccessFile oSavedFile;
  long nPos;

  public FileAccess() throws IOException{
    this("",0);
  }

  public FileAccess(String sName,long nPos) throws IOException{
    oSavedFile = new RandomAccessFile(sName,"rw");
    this.nPos = nPos;
    oSavedFile.seek(nPos);
  }

  public synchronized int write(byte[] b,int nStart,int nLen){
    int n = -1;
    try{
      oSavedFile.write(b,nStart,nLen);
      n = nLen;
    }
    catch(IOException e){
      e.printStackTrace ();
    }
    return n;
  }
}