怎么用Java实现向钉钉小机器人发送文件

你可以使用Java中的HttpURLConnection类来向钉钉小机器人发送文件。首先，你需要获取钉钉机器人的webhook地址，然后使用以下代码将文件发送给机器人：

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

public class DingTalkRobot {
    public static void main(String[] args) throws Exception {
        String webhook = "https://oapi.dingtalk.com/robot/send?access_token=xxxxxxxxxxxxxxxxxxxxxx"; // 替换为你的钉钉机器人webhook地址
        String filePath = "C:/test.txt"; // 替换为你要发送的文件路径

        URL url = new URL(webhook);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW");

        conn.setDoOutput(true);
        conn.setDoInput(true);

        OutputStream out = conn.getOutputStream();
        FileInputStream fileInputStream = new FileInputStream(filePath);
        byte[] buffer = new byte[1024];
        int len;
        while ((len = fileInputStream.read(buffer)) != -1) {
            out.write(buffer, 0, len);
        }
        fileInputStream.close();

        out.flush();
        out.close();

        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = in.readLine()) != null) {
            System.out.println(line);
        }
        in.close();
    }
}

这段代码会将指定路径下的文件发送给钉钉机器人。注意，你需要将webhook地址和文件路径替换为你自己的。