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

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：

package test.socket;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class FileServer {    
    private int port = 4000;
    
    public FileServer(int port){
        this.port = port;
        }        
    
    void start(){
        Socket socket = null;
        ServerSocket server = null;
        DataInputStream inputStream = null;
        DataOutputStream fileOut = null;
        long len = 0;
        int bufferSize = 8192;  //缓冲区大小
        byte[] buf = new byte[bufferSize];
        String savePath = null;
        while (true) {
            try {
                server = new ServerSocket(port);        
                socket = server.accept();       
                System.out.println("建立socket链接");
                
                savePath = "d:\\\\";
                inputStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));                        
                savePath += inputStream.readUTF();  //接收从客户端传来的文件名 
                
                int passedlen = 0;   //文件大小
                len = inputStream.readLong();   //接收从客户端传来的文件的大小
                fileOut = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(savePath)));                                
                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) { //文件末尾
                        break;
                        }
                    //打印传输百分比
                    System.out.println("文件接收了" +  (passedlen * 100L/ len) + "%");
                    fileOut.write(buf, 0, read);
                    }
                fileOut.close();
                inputStream.close();
                System.out.println("接收完成，文件存为" + savePath);
                }
            //}
        catch (NumberFormatException e) {
            e.printStackTrace();
            } 
        catch (IOException e){
            e.printStackTrace();
            }
        finally{
            try {
                if(null != server){
                    socket.close();
                    server.close();
                    } 
                }
            catch (IOException e) {
                e.printStackTrace();
                System.out.println("出错了");
                }
            }
        }
    }

    public static void main(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 FileServer -p port";
        int port = 4000; //默认端口是4000
        
        if (2 != 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]);
                break;
                }
            }
        new FileServer(port).start();
        }        
    }


客户端：

package test.socket;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;

public class FileClient {    
    private int port = 4000; //默认短裤为4000
    private String ipAddress = "localhost"; //默认地址是本机
    private String localFileName;
    private String remoteFileName;    
    
    public FileClient(int port,String ipAddress,String localFileName,String remoteFileName){
        this.port = port;
        this.ipAddress = ipAddress;
        this.localFileName = localFileName;
        this.remoteFileName = remoteFileName;
        }    
    
    void start(){
        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 = new File(localFileName);
            //本地保存路径，文件名会自动从服务器端继承而来。
            socket = new Socket(ipAddress, port);    
            //发送数据到服务器端                    
            is = new DataInputStream(new BufferedInputStream(new FileInputStream(localFileName)));
            os = new DataOutputStream(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 void main(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];
            }
        }
        new FileClient(port,ipAddress,localFileName,remoteFileName).start();
        }
    }