java 网络编程之TCP通信和简单的文件上传功能实例

Socket client_socket = new Socket("192.168.100.17",8888); //客户端套接字(Socket类的套接字为已连接套接字)
ServerSocket listen_socket = new ServerSocket(8888);  //服务端套接字，此时为监听套接字(已经bind()地址和端口了)

Socket server_scoket = socket.accept();
Socket server_scoket2 = socket.accept();
Socket server_scoket3 = socket.accept();

public static void main(String[] args) throws IOException {
 ServerSocket listen_sock = new ServerSocket(8888); //监听套接字只需创建一个，因此在任务之外
 while (true) { //每建立一个连接，就开启一个线程
  Socket conn_sock = listen_sock.accept(); //没有新连接进来时，main主线程阻塞在此
  new Thread(new ThreadTask(conn_sock)).start();
 }
}

OutputStream send_stream = client_socket.getOutputStream(); //客户端获取输出流
InputStream recv_stream = server_socket.getInputStream();

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
public class TCPClient {
 public static void main(String[] args) {
 // 1.创建客户端套接字
 Socket c_sock = null;
 OutputStream client_outstream = null;
 try {
  c_sock = new Socket("192.168.0.124",8888);
  // 2.获取输出流
  client_outstream = c_sock.getOutputStream();
  // 3.输出数据
  client_outstream.write("Hello,i'm coming".getBytes());
 } catch (IOException e) {
  e.printStackTrace();
 } finally {
  if(c_sock != null){
  try{
   c_sock.close();
  } catch(IOException e) {
   e.printStackTrace();
  }
  }
 }
 }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
public class TCPServer {
 public static void main(String[] args) {
 // 1.创建监听套接字
 ServerSocket listen_sock = null;
 try {
  listen_sock = new ServerSocket(8888);
 } catch(IOException i) {
  i.printStackTrace();
 }
 Socket server_sock = null;
 InputStream in_sock = null;
 while (true) {
  try {
  // 2.和客户端建立连接，生成已连接套接字，并获取客户端ip地址
  server_sock = listen_sock.accept();
  String client_ip = server_sock.getInetAddress().getHostAddress();
  System.out.println("Client: " + client_ip + " connected");
  // 3.根据已连接套接字，获取输入流，读取客户端发送的数据
  in_sock = server_sock.getInputStream();
  BufferedReader bufr = new BufferedReader(new InputStreamReader(in_sock));
  String line = null;
  while ((line = bufr.readLine()) != null) {
   System.out.println(line);
  }
  // 4.关闭已连接套接字
  server_sock.close();
  } catch (IOException e) {
  e.printStackTrace();
  }
 }
 }
}

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
public class UploadClient {
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  String server_addr = "192.168.0.124";
  int server_port = 8888;
  Socket send_sock = null;
  FileInputStream local_read = null;
  try {
   // 1.客户端套接字
   send_sock = new Socket(server_addr, server_port);
   // 2.获取连接管道的输出流
   OutputStream send_stream = send_sock.getOutputStream();
   // 3.字节输入流读取本地文件数据，并使用套接字的输出流发送出去
   local_read = new FileInputStream("d:/myjava/net/SQL.docx");
   byte[] buf = new byte[1024];
   int len = 0;
   while ((len = local_read.read(buf)) != -1) {
    send_stream.write(buf, 0, len);
   }
   // 4.标记输出流到结尾
   send_sock.shutdownOutput();
   // 5.接收服务端的反馈数据，如上传成功，上传失败等
   InputStream recv_stream = send_sock.getInputStream();
   BufferedReader ack_recv = new BufferedReader(new InputStreamReader(recv_stream));
   String line = null;
   while ((line = ack_recv.readLine()) != null) {
    System.out.println(line);
   }
  } catch (IOException i) {
   i.printStackTrace();
  } finally {
   if (send_sock != null) {
    try {
     send_sock.close();
     local_read.close();
    } catch (IOException i1) {
     i1.printStackTrace();
    }
   }
   if (local_read != null) {
    try {
     local_read.close();
    } catch (IOException i2) {
     i2.printStackTrace();
    }
   }
  }
 }
}

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class UploadServer {
 public static void main(String[] args) throws IOException {
  ServerSocket listen_sock = new ServerSocket(8888); //监听套接字只需创建一个，因此在任务之外
  while (true) { //每建立一个连接，就开启一个线程
   Socket conn_sock = listen_sock.accept(); //没有新连接进来时，main主线程阻塞在此
   new Thread(new Uploader(conn_sock)).start();
  }
 }
}
class Uploader implements Runnable {
 private File dest_dir = new File("d:/temp"); // 上传目录
 private Socket conn_sock = null; // 连接套接字
 InputStream recv_stream = null;
 FileOutputStream dest_stream = null;
 Uploader(Socket conn_sock) throws IOException {
  this.conn_sock = conn_sock;
 }
 public void run() {
  try {
   if (!dest_dir.exists()) {
    dest_dir.mkdirs();
   }
   // 1.获取连接管道的输入流
   recv_stream = conn_sock.getInputStream();
   // 客户端ip
   String client_ip = conn_sock.getInetAddress().getHostAddress();
   System.out.println(client_ip + ".....connected");
   // 2.文件的上传位置，即输出目标，以ip命名。如果文件已存在，则使用括号加数字新建文件，如"192.168.100.23(1).txt"
   File dest_file = new File(dest_dir, client_ip + ".docx");
   int count = 1;
   while (dest_file.exists()) {
    dest_file = new File(dest_dir, client_ip + "(" + count + ")" + ".docx");
    count++;
   }
   // 3.读取数据并写入目标文件
   dest_stream = new FileOutputStream(dest_file);
   byte[] buf = new byte[1024];
   int len = 0;
   while ((len = recv_stream.read(buf)) != -1) {
    dest_stream.write(buf, 0, len);
   }
   // 4. 向客户端反馈信息
   OutputStream ack_send = conn_sock.getOutputStream();
   byte[] text = "upload successful!".getBytes();
   ack_send.write(text);
  } catch (IOException e1) {
   e1.printStackTrace();
  } finally {
   if (dest_stream != null) {
    try {
     dest_stream.close();
    } catch (IOException i) {
     i.printStackTrace();
    }
   }
   if (conn_sock != null) {
    try {
     conn_sock.close();
    } catch (IOException i) {
     i.printStackTrace();
    }
   }
  }
 }
}