只实现了传送文件的功能。

编写Socket客户端和服务器程序，客户端读取本地文件的数据，发送到服务器，服务器接收并存储到文件中。

消息格式：

字段 长度(单位字节) 内容

--------------------------------------------------------------------

len 8 整个消息长度，不包括这4个字节，类型为long

file_name_length 1 文件名长度，byte

file_name file_name_length 文件名，String

data_length 8 文件数据长度，long

data data_length 文件数据

mac 8 消息的MAC码，byte

客户端执行：

java FileClient -i 192.168.1.171 -p 8888 -f localFileName -r remoteFileName

服务器能连续不断的服务。

服务器端：

1 packagetest.socket;2

3 importjava.io.BufferedInputStream;4 importjava.io.BufferedOutputStream;5 importjava.io.DataInputStream;6 importjava.io.DataOutputStream;7 importjava.io.FileOutputStream;8 importjava.io.IOException;9 importjava.net.ServerSocket;10 importjava.net.Socket;11

12 public classFileServer {13 private int port = 4000;14

15 public FileServer(intport){16 this.port =port;17 }18

19 voidstart(){20 Socket socket = null;21 ServerSocket server = null;22 DataInputStream inputStream = null;23 DataOutputStream fileOut = null;24 long len = 0;25 int bufferSize = 8192; //缓冲区大小

26 byte[] buf = new byte[bufferSize];27 String savePath = null;28 while (true) {29 try{30 server = newServerSocket(port);31 socket =server.accept();32 System.out.println("建立socket链接");33

34 savePath = "d:\\\\";35 inputStream = new DataInputStream(newBufferedInputStream(socket.getInputStream()));36 savePath += inputStream.readUTF(); //接收从客户端传来的文件名

37

38 int passedlen = 0; //文件大小

39 len = inputStream.readLong(); //接收从客户端传来的文件的大小

40 fileOut = new DataOutputStream(new BufferedOutputStream(newFileOutputStream(savePath)));41 System.out.println("文件的长度为:" + len + "\n");42 System.out.println("开始接收文件!" + "\n");43 while (true) {44 int read = 0;45 if (inputStream != null) {46 read =inputStream.read(buf);47 }48 passedlen +=read;49 if (read == -1) { //文件末尾

50 break;51 }52 //打印传输百分比

53 System.out.println("文件接收了" + (passedlen * 100L/ len) + "%");54 fileOut.write(buf, 0, read);55 }56 fileOut.close();57 inputStream.close();58 System.out.println("接收完成，文件存为" +savePath);59 }60 //}

61 catch(NumberFormatException e) {62 e.printStackTrace();63 }64 catch(IOException e){65 e.printStackTrace();66 }67 finally{68 try{69 if(null !=server){70 socket.close();71 server.close();72 }73 }74 catch(IOException e) {75 e.printStackTrace();76 System.out.println("出错了");77 }78 }79 }80 }81

82 public static voidmain(String[] args){83 String usageMsg = "格式错误，请在带参数的eclipse下按照格式输入：\r\n"

84 + "java FileServer -p port";85 int port = 4000; //默认端口是4000

86

87 if (2 !=args.length){88 System.out.println(usageMsg);89 System.exit(1);90 }91

92 for (int i = 0; i < args.length; i++){93 if (args[i].equals("-p") || args[i].equals("-P")){94 port = Integer.parseInt(args[i+1]);95 break;96 }97 }98 newFileServer(port).start();99 }100 }

客户端：

packagetest.socket;importjava.io.BufferedInputStream;importjava.io.DataInputStream;importjava.io.DataOutputStream;importjava.io.File;importjava.io.FileInputStream;importjava.io.IOException;importjava.net.Socket;public classFileClient {private int port = 4000; //默认短裤为4000

private String ipAddress = "localhost"; //默认地址是本机

privateString localFileName;privateString remoteFileName;public FileClient(intport,String ipAddress,String localFileName,String remoteFileName){this.port =port;this.ipAddress =ipAddress;this.localFileName =localFileName;this.remoteFileName =remoteFileName;

}voidstart(){int bufferSize = 8192;byte[] buf = new byte[bufferSize];

Socket socket= null;//读取文件

DataInputStream is = null;//输出数据到服务器端

DataOutputStream os = null;try{

File localFile= newFile(localFileName);//本地保存路径，文件名会自动从服务器端继承而来。

socket = newSocket(ipAddress, port);//发送数据到服务器端

is = new DataInputStream(new BufferedInputStream(newFileInputStream(localFileName)));

os= newDataOutputStream(socket.getOutputStream());//传送localFile文件名和remoteFile文件

os.writeUTF(remoteFileName);

os.flush();

os.writeLong((long) localFile.length());

os.flush();while (true) {int read = 0;if (is != null) {

read=is.read(buf);

}if (read == -1) {break;

}

os.write(buf,0, read);

}

os.flush();

os.close();

is.close();

}catch(IOException e){

e.printStackTrace();

System.out.println("接收消息错误" + "\n");

}finally{if( null !=socket){try{

socket.close();

System.out.println("文件传输完成");

}catch(IOException e) {

e.printStackTrace();

}

}

}

}public static voidmain(String[] args) {

String usageMsg= "格式错误，请在带参数的eclipse下按照格式输入：\r\n"

+ "java FileClient -i ipAddress"

+ "-p port -f localFileName -r remoteFileName";int port = 4000;

String ipAddress= null;

String localFileName= null;

String remoteFileName= null;if(8 !=args.length){

System.out.println(usageMsg);

System.exit(1);

}for(int i = 0; i < args.length; i++){if(args[i].equals("-p") || args[i].equals("-P")){

port= Integer.parseInt(args[i+1]);

}else if(args[i].equals("-i") || args[i].equals("-I")){

ipAddress= args[i+1];

}else if(args[i].equals("-f") || args[i].equals("-F")){

localFileName= args[i+1];

}else if(args[i].equals("-r") || args[i].equals("-R")){

remoteFileName= args[i+1];

}

}newFileClient(port,ipAddress,localFileName,remoteFileName).start();

}

}