JavaTCP通信程序

3 TCP通信程序

3.1 TCP通信原理

TCP通信协议是一种可靠的网络协议，它在通信的两端名建立一个Socke对象，从而在通信的两端形成网络虚拟链路
一旦建立了虚拟的网络链路，两端的程序就可以通过虚拟链路进行通信
Java对基于TCP协议的的网络提供了良好的封装,使用Socket对象来代表两端的通信端口，并通过Socket产生l0流来进行网络通信
Java为客户端提供了Socket类,为服务器端提供了ServerSocket类

3.2 TCP发送数据

发送数据的步骤
- 1、创建客户端的Socket对象(Socket)：Socket(String host, int port)
- 2、获取输出流，写数据：OutputStream对象的getOutputStream()方法
- 3、释放资源：void close()
范例：

package test;

import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //1、创建客户端的Socket对象(Socket)：Socket(String host, int port)
        Socket s = new Socket("127.0.0.1",1000);

        //2、获取输出流，写数据：OutputStream对象的getOutputStream()方法
        OutputStream os = s.getOutputStream();
        os.write("hello,java".getBytes());

        //3、释放资源：void close()
        s.close();
    }
}

3.3 TCP接收数据

接收数据的步骤
- 1、创建服务器端的Socket对象(ServerSocket)：ServerSocket(int port)
- 2、监听客户端连接, 返回个Socket对象:Socket accept()
- 3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
- 4、释放资源：void close()
范例

package test;

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //1、创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        //2、监听客户端连接, 返回个Socket对象:Socket accept()
        Socket s = ss.accept();

        //3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
        InputStream is = s.getInputStream();
        byte[] bys = new byte[1014];
        int len = is.read(bys);
        String data = new String(bys,0,len);
        System.out.println(data);

        //4、释放资源：void close()
        s.close();
        ss.close();
    }
}

3.4 案例

3.4.1 练习一：服务器给出反馈

在这里插入图片描述

客户端

package test;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //1、创建客户端的Socket对象(Socket)：Socket(String host, int port)
        Socket s = new Socket("127.0.0.1",1000);

        //2、获取输出流，写数据：OutputStream对象的getOutputStream()方法
        OutputStream os = s.getOutputStream();
        os.write("hello,java".getBytes());

        //接收服务器反馈
        InputStream is = s.getInputStream();
        byte[] bys = new byte[1024];
        int len = is.read(bys);
        String data = new String(bys,0,len);
        System.out.println("客户端:"+data);

        //3、释放资源：void close()
        s.close();
        
        //客户端:数据已经收到
    }
}

服务器

package test;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //1、创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        //2、监听客户端连接, 返回个Socket对象:Socket accept()
        Socket s = ss.accept();

        //3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
        InputStream is = s.getInputStream();
        byte[] bys = new byte[1014];
        int len = is.read(bys);
        String data = new String(bys,0,len);
        System.out.println("服务器："+data);

        //给出反馈
        OutputStream os = s.getOutputStream();
        os.write("数据已经收到".getBytes());

        //4、释放资源：void close()
        s.close();
        ss.close();

        //服务器：hello,java
    }
}

3.4.2 练习二：客户端数据来源于键盘录入

在这里插入图片描述

客户端

package test;

import java.io.*;
import java.net.Socket;

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //创建客户端的Socket对象(Socket)：Socket(String host, int port)
        Socket s = new Socket("127.0.0.1",1000);

        //数据来源于键盘录入，直到886停止
        System.out.println("请输入数据");
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        //封装输出流对象
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        String line;
        while((line= br.readLine())!=null) {
            if("886".equals(line)) {
                break;
            }

            //获取输出流对象
            bw.write(line);
            bw.newLine();
            bw.flush();
        }

        //释放资源
        s.close();

//        hello
//        886
    }
}

服务器

package test;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //1、创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        //2、监听客户端连接, 返回个Socket对象:Socket accept()
        Socket s = ss.accept();

        //3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
//        InputStream is = s.getInputStream();
//        InputStreamReader isr = new InputStreamReader(is);
//        BufferedReader br = new BufferedReader(isr);
        BufferedReader br  = new BufferedReader(new InputStreamReader(s.getInputStream()));
        String line;
        while((line=br.readLine())!=null) {
            System.out.println(line);
        }


        //4、释放资源：void close()
        s.close();
        //hello
    }
}

3.4.3 练习三：服务器数据写入文本文件

在这里插入图片描述

服务器

package test;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //1、创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        //2、监听客户端连接, 返回个Socket对象:Socket accept()
        Socket s = ss.accept();

        //3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
        BufferedReader br  = new BufferedReader(new InputStreamReader(s.getInputStream()));
        //把数据写入文本文件
        BufferedWriter bw = new BufferedWriter(new FileWriter("E:\\test\\java.txt"));

        String line;
        while((line=br.readLine())!=null) {
            bw.write(line);
            bw.newLine();
            bw.flush();
        }


        //4、释放资源：void close()
        bw.close();
        ss.close();
        //文件中数据：hello
    }
}

3.4.4 练习四：客户端数据来源于文本文件

在这里插入图片描述

客户端

package test;

import java.io.*;
import java.net.Socket;

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //创建客户端的Socket对象(Socket)：Socket(String host, int port)
        Socket s = new Socket("127.0.0.1",1000);

        //封装文本文件数据
        BufferedReader br  =new BufferedReader(new FileReader("E:\\test\\fos.txt"));
        //封装输出流对象
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        String line;
        while((line= br.readLine())!=null) {
            //获取输出流对象
            bw.write(line);
            bw.newLine();
            bw.flush();
        }

        //释放资源
        br.close();
        s.close();
    }
}

3.4.5 练习五：上传文件服务器给出反馈

![在这里插入图片描述](https://img-blog.csdnimg.cn/5505

客户端

package test;

import java.io.*;
import java.net.Socket;

public class ClientDemo {
    public static void main(String[] args) throws IOException {
        //创建客户端的Socket对象(Socket)：Socket(String host, int port)
        Socket s = new Socket("127.0.0.1",1000);

        //封装文本文件数据
        BufferedReader br  =new BufferedReader(new FileReader("E:\\test\\fos.txt"));
        //封装输出流对象
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        String line;
        while((line= br.readLine())!=null) {
            //获取输出流对象
            bw.write(line);
            bw.newLine();
            bw.flush();
        }

//        //自定义结束标记
//        bw.write("886");
//        bw.newLine();
//        bw.flush();
        s.shutdownOutput();//Socket类中方法：表示输出结束

        //接收反馈
        BufferedReader brClient = new BufferedReader(new InputStreamReader(s.getInputStream()));
        String data = brClient.readLine(); //等待读取数据
        System.out.println("服务器的反馈:"+data); //服务器的反馈:文件上传成功

        //释放资源
        br.close();
        s.close();
    }
}

服务端

package test;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //1、创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        //2、监听客户端连接, 返回个Socket对象:Socket accept()
        Socket s = ss.accept();

        //3、获取输入流, 读数据，并把数据显示在控制台:InputStream对象的getInputStream()方法
        BufferedReader br  = new BufferedReader(new InputStreamReader(s.getInputStream()));
        //把数据写入文本文件
        BufferedWriter bw = new BufferedWriter(new FileWriter("E:\\test\\java.txt"));

        String line;
        while((line=br.readLine())!=null) { //等待读取数据
//            if("886".equals(line)) {
//                break;
//            }
            bw.write(line);
            bw.newLine();
            bw.flush();
        }

        //给出反馈
        BufferedWriter bwServer = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
        bwServer.write("文件上传成功");
        bwServer.newLine();
        bwServer.flush();

        //4、释放资源：void close()
        bw.close();
        ss.close();
    }
}

3.4.6 练习六：多线程实现文件上传

在这里插入图片描述

服务端

package test;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class SeverDemo {
    public static void main(String[] args) throws IOException {
        //创建服务 器端的Socket对象(ServerSocket)：ServerSocket(int port)
        ServerSocket ss = new ServerSocket(1000);

        while(true) {
            //监听客户端连接, 返回个Socket对象:Socket accept()
            Socket s = ss.accept();
            //为每一个客户端开启一个线程
            new Thread(new ServerThread(s)).start();
        }
    }
}

服务端多线程

package test;

import java.io.*;
import java.net.Socket;

public class ServerThread implements Runnable {
    private Socket s;
    public ServerThread(Socket s) {
        this.s = s;
    }

    @Override
    public void run() {
        try {
            //接收数据写入文本文件
            BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
//            BufferedWriter bw = new BufferedWriter(new FileWriter("E:\\test\\java.txt"));
            //解决名称冲突问题，上传到不同文件中
            int count = 0;
            File file = new File("E:\\test\\["+count+"]java.txt");
            while(file.exists()) {
                count++;
                file = new File("E:\\test\\["+count+"]java.txt");
            }
            BufferedWriter bw = new BufferedWriter(new FileWriter(file));
            
            String line;
            while ((line=br.readLine()) != null) {
                bw.write(line);
                bw.newLine();
                bw.flush();
            }

            //给出反馈
            BufferedWriter bwSever  =new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
            bwSever.write("文件上传成功");
            bwSever.newLine();
            bwSever.flush();

            //释放资源
            s.close();

        }catch (IOException e) {
            e.printStackTrace();
        }
    }
}