Java基于Socket文件传输示例

需要进行网络传输大文件，于是对基于socket的文件传输作了一个初步的了解。在一位网友提供的程序基础上，俺进行了一些加工，采用了缓冲输入/输出流来包装输出流，再采用数据输入/输出输出流进行包装，加快传输的速度。废话少说，先来看服务器端的程序。

1.服务器端

import  java.io.BufferedInputStream;import  java.io.DataInputStream;import  java.io.DataOutputStream;import  java.io.File;import  java.io.FileInputStream;import  java.net.ServerSocket;import  java.net.Socket;public   class  ServerTest  {     int  port  =   8821 ;     void  start()  {        Socket s  =   null ;         try   {            ServerSocket ss  =   new  ServerSocket(port);             while  ( true )  {                 //  选择进行传输的文件                String filePath  =   " D://lib.rar " ;                File fi  =   new  File(filePath);                System.out.println( " 文件长度: "   +  ( int ) fi.length());                 //  public Socket accept() throws                 //  IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。                s  =  ss.accept();                System.out.println( " 建立socket链接 " );                DataInputStream dis  =   new  DataInputStream( new  BufferedInputStream(s.getInputStream()));                dis.readByte();                DataInputStream fis  =   new  DataInputStream( new  BufferedInputStream( new  FileInputStream(filePath)));                DataOutputStream ps  =   new  DataOutputStream(s.getOutputStream());                 // 将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 4th里有现成的代码。                ps.writeUTF(fi.getName());                ps.flush();                ps.writeLong(( long ) fi.length());                ps.flush();                 int  bufferSize  =   8192 ;                 byte [] buf  =   new   byte [bufferSize];                 while  ( true )  {                     int  read  =   0 ;                     if  (fis  !=   null )  {                        read  =  fis.read(buf);                    }                     if  (read  ==   - 1 )  {                         break ;                    }                    ps.write(buf,  0 , read);                }                ps.flush();                 //  注意关闭socket链接哦，不然客户端会等待server的数据过来，                 //  直到socket超时，导致数据不完整。                                fis.close();                s.close();                                System.out.println( " 文件传输完成 " );            }        }   catch  (Exception e)  {            e.printStackTrace();        }    }     public   static   void  main(String arg[])  {         new  ServerTest().start();    }}

2.socket的Util辅助类

 import  java.net. * ;import  java.io. * ;public   class  ClientSocket  {     private  String ip;     private   int  port;     private  Socket socket  =   null ;    DataOutputStream out  =   null ;    DataInputStream getMessageStream  =   null ;     public  ClientSocket(String ip,  int  port)  {         this .ip  =  ip;         this .port  =  port;    }     /**     * 创建socket连接     *      *  @throws  Exception     *             exception      */     public   void  CreateConnection()  throws  Exception  {         try   {            socket  =   new  Socket(ip, port);        }   catch  (Exception e)  {            e.printStackTrace();             if  (socket  !=   null )                socket.close();             throw  e;        }   finally   {        }    }     public   void  sendMessage(String sendMessage)  throws  Exception  {         try   {            out  =   new  DataOutputStream(socket.getOutputStream());             if  (sendMessage.equals( " Windows " ))  {                out.writeByte( 0x1 );                out.flush();                 return ;            }             if  (sendMessage.equals( " Unix " ))  {                out.writeByte( 0x2 );                out.flush();                 return ;            }             if  (sendMessage.equals( " Linux " ))  {                out.writeByte( 0x3 );                out.flush();            }   else   {                out.writeUTF(sendMessage);                out.flush();            }        }   catch  (Exception e)  {            e.printStackTrace();             if  (out  !=   null )                out.close();             throw  e;        }   finally   {        }    }     public  DataInputStream getMessageStream()  throws  Exception  {         try   {            getMessageStream  =   new  DataInputStream( new  BufferedInputStream(socket.getInputStream()));             return  getMessageStream;        }   catch  (Exception e)  {            e.printStackTrace();             if  (getMessageStream  !=   null )                getMessageStream.close();             throw  e;        }   finally   {        }    }     public   void  shutDownConnection()  {         try   {             if  (out  !=   null )                out.close();             if  (getMessageStream  !=   null )                getMessageStream.close();             if  (socket  !=   null )                socket.close();        }   catch  (Exception e)  {        }    }}

3.客户端

 import  java.io.BufferedOutputStream;import  java.io.DataInputStream;import  java.io.DataOutputStream;import  java.io.FileOutputStream;public   class  ClientTest  {     private  ClientSocket cs  =   null ;     private  String ip  =   " localhost " ; //  设置成服务器IP     private   int  port  =   8821 ;     private  String sendMessage  =   " Windwos " ;     public  ClientTest()  {         try   {             if  (createConnection())  {                sendMessage();                getMessage();            }        }   catch  (Exception ex)  {            ex.printStackTrace();        }    }     private   boolean  createConnection()  {        cs  =   new  ClientSocket(ip, port);         try   {            cs.CreateConnection();            System.out.print( " 连接服务器成功! "   +   " /n " );             return   true ;        }   catch  (Exception e)  {            System.out.print( " 连接服务器失败! "   +   " /n " );             return   false ;        }    }     private   void  sendMessage()  {         if  (cs  ==   null )             return ;         try   {            cs.sendMessage(sendMessage);        }   catch  (Exception e)  {            System.out.print( " 发送消息失败! "   +   " /n " );        }    }     private   void  getMessage()  {         if  (cs  ==   null )             return ;        DataInputStream inputStream  =   null ;         try   {            inputStream  =  cs.getMessageStream();        }   catch  (Exception e)  {            System.out.print( " 接收消息缓存错误/n " );             return ;        }         try   {             // 本地保存路径，文件名会自动从服务器端继承而来。            String savePath  =   " E:// " ;             int  bufferSize  =   8192 ;             byte [] buf  =   new   byte [bufferSize];             int  passedlen  =   0 ;             long  len = 0 ;                        savePath  +=  inputStream.readUTF();            DataOutputStream fileOut  =   new  DataOutputStream( new  BufferedOutputStream( new  BufferedOutputStream( new  FileOutputStream(savePath))));            len  =  inputStream.readLong();                        System.out.println( " 文件的长度为: "   +  len  +   " /n " );            System.out.println( " 开始接收文件! "   +   " /n " );                                 while  ( true )  {                 int  read  =   0 ;                 if  (inputStream  !=   null )  {                    read  =  inputStream.read(buf);                }                passedlen  +=  read;                 if  (read  ==   - 1 )  {                     break ;                }                 // 下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比                System.out.println( " 文件接收了 "   +   (passedlen  *   100 /  len)  +   " %/n " );                fileOut.write(buf,  0 , read);            }            System.out.println( " 接收完成，文件存为 "   +  savePath  +   " /n " );            fileOut.close();        }   catch  (Exception e)  {            System.out.println( " 接收消息错误 "   +   " /n " );             return ;        }    }     public   static   void  main(String arg[])  {         new  ClientTest();    }} 

这就实现了从服务器端向客户端发送文件的过程,当然,反过来,也一样.稍有不同.代码中对跨平台的细节没有实现,

转自【http://www.open-open.com/lib/view/open1390525710507.html】