JavaSE 进阶(二十二)

发表于 更新于 分类于 阅读次数： 本文字数： 8.8k 阅读时长 ≈ 15 分钟

TCP 连接测试

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
package ml.guest997;

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.nio.charset.StandardCharsets;

public class TCPClient {
    public static void main(String[] args) {
        Socket socket = null;
        OutputStream outputStream = null;
        try {
            //发送信息
            socket = new Socket(InetAddress.getByName("localhost"), 9999);
            outputStream = socket.getOutputStream();
            outputStream.write("客户端发送信息...".getBytes(StandardCharsets.UTF_8));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (socket != null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
package ml.guest997;

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

public class TCPServer {
    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        Socket accept = null;
        InputStream inputStream = null;
        ByteArrayOutputStream byteArrayOutputStream = null;
        try {
            //创建连接
            serverSocket = new ServerSocket(9999);
            //等待客户端请求
            accept = serverSocket.accept();
            //读取用户信息
            inputStream = accept.getInputStream();
            //管道流接收和打印
            byteArrayOutputStream = new ByteArrayOutputStream();
            byte[] bytes = new byte[1024];
            int len = 0;
            while ((len = inputStream.read(bytes)) != -1) {
                byteArrayOutputStream.write(bytes, 0, len);
            }
            System.out.println(byteArrayOutputStream);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (byteArrayOutputStream != null) {
                try {
                    byteArrayOutputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (accept != null) {
                try {
                    accept.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (serverSocket != null) {
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

TCP 文件上传

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
package ml.guest997;

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

public class FileClient {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket(InetAddress.getByName("localhost"), 9999);
            OutputStream outputStream = socket.getOutputStream();
            FileInputStream fileInputStream = new FileInputStream("pc.png");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = fileInputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, len);
            }
            //通知服务器文件已发送完毕
            socket.shutdownOutput();
            //确定服务端接收完毕，才断开连接。
            InputStream inputStream = socket.getInputStream();
            byte[] buffer2 = new byte[1024];
            int len2;
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            while ((len2 = inputStream.read(buffer2)) != -1) {
                byteArrayOutputStream.write(buffer2, 0, len2);
            }
            System.out.println(byteArrayOutputStream);
            System.out.println("客户端断开连接...");
            byteArrayOutputStream.close();
            inputStream.close();
            outputStream.close();
            fileInputStream.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
package ml.guest997;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;

public class FileServer {
    public static void main(String[] args) {
        try {
            ServerSocket serverSocket = new ServerSocket(9999);
            Socket accept = serverSocket.accept();
            InputStream inputStream = accept.getInputStream();
            FileOutputStream fileOutputStream = new FileOutputStream("receive.png");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = inputStream.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, len);
            }
            OutputStream outputStream = accept.getOutputStream();
            outputStream.write("服务端接收成功...".getBytes(StandardCharsets.UTF_8));
            outputStream.close();
            fileOutputStream.close();
            inputStream.close();
            accept.close();
            serverSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

UDP 发送消息

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
package ml.guest997;

import java.io.IOException;
import java.net.*;
import java.nio.charset.StandardCharsets;

public class UDPSend {
    public static void main(String[] args) {
        try {
            DatagramSocket datagramSocket = new DatagramSocket();
            String msg = "发送消息...";
            DatagramPacket datagramPacket = new DatagramPacket(msg.getBytes(StandardCharsets.UTF_8), 0, msg.getBytes(StandardCharsets.UTF_8).length, InetAddress.getByName("127.0.0.1"), 9999);
            datagramSocket.send(datagramPacket);
            datagramSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
package ml.guest997;

import java.io.IOException;
import java.net.*;

public class UDPReceive {
    public static void main(String[] args) {
        try {
            DatagramSocket datagramSocket = new DatagramSocket(9999, InetAddress.getByName("127.0.0.1"));
            byte[] buffer = new byte[1024];
            DatagramPacket datagramPacket = new DatagramPacket(buffer, 0, buffer.length);
            datagramSocket.receive(datagramPacket);
            System.out.println(new String(buffer, 0, datagramPacket.getLength()));  //不能直接使用 datagramPacket.getData()，因为未赋值的位数全是0。
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

UDP 实现聊天

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
package ml.guest997;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.*;
import java.nio.charset.StandardCharsets;

//发送消息
public class ChatSend implements Runnable {
    DatagramSocket datagramSocket;
    BufferedReader reader;

    private int fromPort;
    private int toPort;

    public ChatSend(int fromPort, int toPort) {
        this.fromPort = fromPort;
        this.toPort = toPort;
        try {
            this.datagramSocket = new DatagramSocket(fromPort);
            reader = new BufferedReader(new InputStreamReader(System.in));
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while (true) {
            try {
                String s = reader.readLine();
                byte[] data = s.getBytes(StandardCharsets.UTF_8);
                DatagramPacket datagramPacket = new DatagramPacket(data, 0, data.length, new InetSocketAddress("localhost", this.toPort));
                datagramSocket.send(datagramPacket);
                if ("bye".equals(s)) {
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
package ml.guest997;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

//接收消息
public class ChatReceive implements Runnable {
    DatagramSocket datagramSocket;

    private String from;
    private int port;

    public ChatReceive(String from, int port) {
        this.from = from;
        this.port = port;
        try {
            this.datagramSocket = new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while (true) {
            try {
                byte[] cache = new byte[1024];
                DatagramPacket datagramPacket = new DatagramPacket(cache, 0, cache.length);
                datagramSocket.receive(datagramPacket);
                String receiveData = new String(datagramPacket.getData(), 0, datagramPacket.getLength());
                System.out.println(from + "：" + receiveData);
                if ("bye".equals(receiveData)) {
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
1
2
3
4
5
6
7
8
package ml.guest997;

public class ChatServer {
    public static void main(String[] args) {
        new Thread(new ChatSend(6666, 7777)).start();
        new Thread(new ChatReceive("客户端", 8888)).start();
    }
}
1
2
3
4
5
6
7
8
package ml.guest997;

public class ChatClient {
    public static void main(String[] args) {
        new Thread(new ChatSend(9999, 8888)).start();
        new Thread(new ChatReceive("服务端", 7777)).start();
    }
}

下载网络资源

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
package ml.guest997;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class Download {
    public static void main(String[] args) {
        try {
            URL url = new URL("https://guest997.ml/wp-content/themes/Sakurairo-2.1.1.1/homepage.mp4");
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
            InputStream inputStream = urlConnection.getInputStream();
            FileOutputStream fos = new FileOutputStream("homepage.mp4");
            byte[] buffer = new byte[1024];
            int len;
            while ((len = inputStream.read(buffer)) != -1) {
                fos.write(buffer, 0, len);
            }
            fos.close();
            inputStream.close();
            urlConnection.disconnect();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}