java get请求传json数据 比如传一个long类型的id

可以使用以下代码实现：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        try {
            // 设置请求参数
            long id = 123456L;
            Map<String, Object> params = new HashMap<>();
            params.put("id", id);

            // 拼接请求url
            StringBuilder sb = new StringBuilder("http://example.com/api/getData");
            sb.append("?").append(buildParams(params));

            // 发送请求
            URL url = new URL(sb.toString());
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");

            // 读取响应内容
            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuilder response = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            reader.close();
            System.out.println(response.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 将请求参数转换为url参数格式
    private static String buildParams(Map<String, Object> params) {
        if (params == null || params.isEmpty()) {
            return "";
        }
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, Object> entry : params.entrySet()) {
            if (sb.length() > 0) {
                sb.append("&");
            }
            sb.append(entry.getKey()).append("=").append(entry.getValue());
        }
        return sb.toString();
    }
}

以上代码将会发送一个GET请求到`http://example.com/api/getData?id=123456`，其中id的值为123456。你可以根据自己的需要修改请求url和参数。