TCP网络编程

public class TCPTest {
    @Test
    public void client() {
        Socket socket = null;
        OutputStream os = null;
        try {
            //1.创建Socket对象，指明服务器端的ip和端口号
            InetAddress inet = InetAddress.getByName("127.0.0.1");
            socket = new Socket(inet, 8899);
            //2.获取一个输出流，用于输出数据
            os = socket.getOutputStream();
            //3.写出数据的操作
            os.write("hello哈哈哈".getBytes());
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //4.资源关闭
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    @Test
    public void server(){
        ServerSocket serverSocket = null;
        Socket socket = null;
        InputStream is = null;
        ByteArrayOutputStream baos = null;
        try {
            //1.创建服务器端的ServerSocket，指明自己的端口号
            serverSocket = new ServerSocket(8899);
            //调用accept()表示接收来自于客户端的socket
            socket = serverSocket.accept();
            //3.获取输入流
            is = socket.getInputStream();
            //4.读取输入流中的数据
            baos = new ByteArrayOutputStream();
            byte[] bcuf = new byte[5];
            int len;
            while ((len = is.read(bcuf)) != -1) {
                baos.write(bcuf, 0, len);
            }
            System.out.println(baos.toString());
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if(baos!=null){
                try {
                    baos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(baos!=null){
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(baos!=null){
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(baos!=null){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

　　

public class TCPTest2 {
    @Test
    public void client() throws IOException {
        InetAddress inet = InetAddress.getByName("127.0.0.1");
        Socket socket = new Socket(inet,8899);
        OutputStream os = socket.getOutputStream();

        File file = new File("hello.txt");
        FileInputStream fis = new FileInputStream(file);
        byte[] bytes = new byte[1024];
        int len;
        while ((len=fis.read(bytes))!=-1){
            os.write(bytes,0,len);
        }

        socket.shutdownOutput();
        fis.close();
        os.close();
        socket.close();

    }

    @Test
    public void server() throws IOException {
        FileOutputStream fos = new FileOutputStream("hello3.txt");
        ServerSocket ss = new ServerSocket(8899);
        Socket socket = ss.accept();

        InputStream is = socket.getInputStream();
        byte[] bytes = new byte[1024];
        int len;
        while ((len=is.read(bytes))!=-1){
            fos.write(bytes,0,len);
        }

        is.close();
        socket.close();
        fos.close();
    }

}