tr-agent-client/src/main/java/com/tongran/agent/client/utils/PublicIpFetcher.java

package com.tongran.agent.client.utils;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class PublicIpFetcher {

    private static final String IP_SERVICE_URL = "https://myip.ipip.net";
    private static final int TIMEOUT_MS = 10_000; // 10秒超时

    /**
     * 获取公网 IP（包含归属地信息）
     *
     * @return IP 信息字符串，如 "当前 IP：112.96.15.145，来自于：中国 广东省 深圳市 联通"
     * @throws IOException 如果网络请求失败
     */
    public static String getPublicIp() throws IOException {
        URL url = new URL(IP_SERVICE_URL);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        // 设置请求方法
        connection.setRequestMethod("GET");
        connection.setConnectTimeout(TIMEOUT_MS);
        connection.setReadTimeout(TIMEOUT_MS);

        // 发起请求
        int responseCode = connection.getResponseCode();
        if (responseCode != 200) {
            throw new IOException("HTTP " + responseCode + " from " + IP_SERVICE_URL);
        }

        // 读取响应（注意：myip.ipip.net 返回的是 GBK 编码）
        try (BufferedReader reader = new BufferedReader(
                new InputStreamReader(connection.getInputStream(), "GBK"))) { // 使用 GBK 解码
            StringBuilder response = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            return response.toString().trim();
        }
    }

    /**
     * 从返回文本中提取纯 IP 地址（如 112.96.15.145）
     *
     * @param ipInfo 来自 getPublicIp() 的完整信息
     * @return 纯 IP 字符串，提取失败返回 null
     */
    public static String extractIp(String ipInfo) {
        if (ipInfo == null || ipInfo.isEmpty()) return null;

        // 匹配 IP 地址的正则
        java.util.regex.Pattern pattern = java.util.regex.Pattern.compile("(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})");
        java.util.regex.Matcher matcher = pattern.matcher(ipInfo);
        return matcher.find() ? matcher.group(1) : null;
    }

    // === 使用示例 ===
    public static void main(String[] args) {
        try {
            String ipInfo = getPublicIp();
            System.out.println("完整信息: " + ipInfo);

            String pureIp = extractIp(ipInfo);
            if (pureIp != null) {
                System.out.println("公网 IP: " + pureIp);
            } else {
                System.out.println("未能提取 IP 地址");
            }

        } catch (IOException e) {
            System.err.println("获取公网 IP 失败: " + e.getMessage());
            e.printStackTrace();
        }
    }
}