springboot NTRIP demo

NTRIP (Networked Transport of RTCM via Internet Protocol) 是一种用于传输差分 GPS 数据的协议。Spring Boot 是一个快速开发框架，可以轻松构建基于 Java 的 Web 应用程序。在这里，我将为您提供一个使用 Spring Boot 构建 NTRIP 客户端的简单示例。

1. 首先，您需要在您的 Spring Boot 项目中添加以下依赖项：

<dependency>
    <groupId>com.github.anthunt</groupId>
    <artifactId>ntripclient</artifactId>
    <version>1.0.5</version>
</dependency>

2. 然后，您需要创建一个 NTRIP 客户端类，该类将负责与 NTRIP 服务器进行通信。以下是一个简单的示例：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.Socket;

import org.springframework.stereotype.Component;

@Component
public class NtripClient {

    private static final String SERVER_HOST = "your_server_host";
    private static final int SERVER_PORT = 2101;
    private static final String MOUNT_POINT = "your_mount_point";
    private static final String USERNAME = "your_username";
    private static final String PASSWORD = "your_password";

    public void connect() throws Exception {

        // 创建 Socket 连接
        Socket socket = new Socket(SERVER_HOST, SERVER_PORT);

        // 获取输入输出流
        BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        Writer writer = new OutputStreamWriter(socket.getOutputStream());

        // 发送 NTRIP 认证请求
        String authRequest = "GET /" + MOUNT_POINT + " HTTP/1.0\r\n";
        authRequest += "User-Agent: NTRIP Java Client/1.0\r\n";
        authRequest += "Authorization: Basic " + getBase64Credentials() + "\r\n";
        authRequest += "Connection: close\r\n\r\n";
        writer.write(authRequest);
        writer.flush();

        // 读取服务器响应
        String response = "";
        String line;
        while ((line = reader.readLine()) != null) {
            response += line + "\n";
            if (line.isEmpty()) {
                break;
            }
        }

        // 处理响应
        if (response.contains("401 Unauthorized")) {
            throw new Exception("Invalid username or password");
        } else if (response.contains("SOURCETABLE")) {
            throw new Exception("Mount point is a sourcetable");
        } else if (response.contains("ICY 200 OK")) {
            System.out.println("Connected to NTRIP server");
        } else {
            throw new Exception("Unexpected response from NTRIP server");
        }

        // 关闭连接
        socket.close();
    }

    private String getBase64Credentials() {
        String credentials = USERNAME + ":" + PASSWORD;
        return java.util.Base64.getEncoder().encodeToString(credentials.getBytes());
    }
}

3. 最后，在您的应用程序中调用 `NtripClient.connect()` 方法即可连接到 NTRIP 服务器。您可以将此方法添加到您的控制器或服务中，或者在应用程序启动时调用它。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    @Autowired
    private NtripClient ntripClient;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    public void run(String... arg0) throws Exception {
        ntripClient.connect();
    }
}

这是一个非常基本的示例，您可以根据您的需要进行修改和扩展。您可能需要实现更复杂的功能，例如处理 RTCM 数据流或定期获取数据。