Java网络编程02：TCP案例

Java网络编程02：TCP案例

客户端

1. 连接服务器Socket
2. 发送消息

//客户端
public class TcpClientDemo01 {
     
    public static void main(String[] args) {
     

        Socket socket = null;
        OutputStream os = null;

        try {
     
            //1.要知道服务器的地址，端口号
            InetAddress serverIP = InetAddress.getByName("127.0.0.1");
            int port = 9999;
            //2.创建一个socket连接
            socket = new Socket(serverIP,port);
            //3.发送消息  IO流
            os = socket.getOutputStream();
            os.write("你好".getBytes());

        } catch (Exception e) {
     
            e.printStackTrace();
        }finally {
     
            if (os!=null){
     
                try {
     
                    os.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
            if (socket!=null){
     
                try {
     
                    socket.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
        }

    }
}

服务器

1. 建立服务的端口ServerSocket
2. 等待用户的连接 accept
3. 接收用户的消息

//服务端
public class TcpServerDemo01 {
     
    public static void main(String[] args) {
     

        ServerSocket serverSocket = null;
        Socket socket = null;
        InputStream is = null;
        ByteArrayOutputStream baos = null;

        try {
     
            //1.我得有一个地址
            serverSocket = new ServerSocket(9999);
            //2.等待客户端连接过来
            socket = serverSocket.accept();
            //3.读取客户端的消息
            is = socket.getInputStream();

            //管道流
            baos = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int len;
            while ((len=is.read(buffer))!=-1){
     
                baos.write(buffer,0,len);
            }

            System.out.println(baos.toString());

        } catch (IOException e) {
     
            e.printStackTrace();
        }finally {
     
            //关闭资源
            if (baos!=null){
     
                try {
     
                    baos.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
            if (is!=null){
     
                try {
     
                    is.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
            if (socket!=null){
     
                try {
     
                    socket.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
            if (serverSocket!=null){
     
                try {
     
                    serverSocket.close();
                } catch (IOException e) {
     
                    e.printStackTrace();
                }
            }
        }

    }
}

文件上传

客户端

public class TcpClientDemo02 {
     

    public static void main(String[] args) throws Exception {
     

        //1.创建一个Socket连接
        Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9000);
        //2.创建一个输出流
        OutputStream os = socket.getOutputStream();
        //3.读取文件
        FileInputStream fis = new FileInputStream(new File("a.txt"));
        //4.写出文件
        byte[] buffer = new byte[1024];
        int len;
        while ((len=fis.read(buffer))!=-1){
     
            os.write(buffer,0,len);
        }

        //同值服务器，我已经结束了
        socket.shutdownInput();//我已经传输完毕了

        //确定服务器接收完毕，才能断开连接
        InputStream inputStream = socket.getInputStream();
        //String byte[]
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        byte[] buffer2 = new byte[2048];
        int len2;
        while ((len2=inputStream.read(buffer2))!=-1){
     
            baos.write(buffer2,0,len2);
        }
        System.out.println(baos.toString());

        //5.关闭支援   （异常就直接抛出了）
        baos.close();
        inputStream.close();
        fis.close();
        os.close();
        socket.close();
    }

}

服务器端

public class TcpServerDemo02 {
     

    public static void main(String[] args) throws Exception {
     

        //1.创建服务
        ServerSocket serverSocket = new ServerSocket(9000);
        //2.监听客户端连接
        Socket socket = serverSocket.accept();//阻塞式监听，会一直等待客户端连接
        //3.获取输入流
        InputStream is = socket.getInputStream();

        //4.文件输出
        FileOutputStream fos = new FileOutputStream(new File("receive.txt"));
        byte[] buffer = new byte[1024];
        int len;
        while ((len=is.read(buffer))!=-1){
     
            fos.write(buffer,0,len);
        }

        //通知客户端我接收完毕了
        OutputStream os = socket.getOutputStream();
        os.write("我接收完毕了，你可以断开了".getBytes());


        //关闭资源
        fos.close();
        is.close();
        socket.close();
        serverSocket.close();
    }

}