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


public class doGet {
    public static void main(String[] args) {

        try {
            String path = "访问的接口地址";
            URL url = new URL(path);
            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setRequestMethod("GET");
            con.setRequestProperty(
                    "User-Agent",
                    "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36");
            con.setRequestProperty("Cookie", "shshs..（省略部分）");
            con.connect();
            if (con.getResponseCode() == 200) {

                BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
                String line;
                StringBuilder sb = new StringBuilder();
                while ((line = br.readLine()) != null) {// 循环读取流
                    sb.append(line);
                }
                br.close();// 关闭流
                System.out.println(sb);
            } else {
                System.out.println(con.getResponseCode());
            }
            con.disconnect();// 断开连接
        } catch (Exception e) {

            System.out.println(e);


        }
    }
}

运行代码，返回接口请求结果：

遇到问题：

（1）因系统需要登录，因此调用接口时，需要配置cookie信息，如果不配置cookie，运行会出现如下结果：