Java如何通过URL调用远程接口并读取返回信息？

1.第一种

        String ticket = "";//登录凭证
        String url_str = "http://www.sina.com.cn?ticket=";//获取用户认证的帐号URL
        String ticket_url = url_str + ticket;
        URL url = new URL(ticket_url);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.connect();

        int code = connection.getResponseCode();
        if (code == 404) {
            throw new Exception("认证无效，找不到此次认证的会话信息！");
        }
        if (code == 500) {
            throw new Exception("认证服务器发生内部错误！");
        }
        if (code != 200) {
            throw new Exception("发生其它错误，认证服务器返回 " + code);
        }
        InputStream is = connection.getInputStream();
        byte[] response = new byte[is.available()];
        is.read(response);
        is.close();
        if (response == null || response.length == 0) {
            throw new Exception("认证无效，找不到此次认证的会话信息！");
        }
        String userId = new String(response, "UTF-8");
        System.out.println(userId);

2.第二种

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONObject;
 
public class TestHuanXin {
public static void main(String[] args) {
    String url="http://www.itxm.net";
        try {
              String request="id=23";
              String response=getData(url,request);
              System.out.println(response);
 
              JSONObject root = new JSONObject(response);
 
              JSONObject jsonObject =root.getJSONObject("data");
 
             String token=jsonObject.getString("access_token");
 
              System.out.println("token="+token);
 
       } catch (Exception e) {
              e.printStackTrace();
       }
}
 
public static String getData(String url, String request)throws UnsupportedEncodingException, IOException {
       String charset = "UTF-8";
       ByteArrayOutputStream outStream = new ByteArrayOutputStream();
       HttpURLConnection connect = (HttpURLConnection) (new URL(url).openConnection());
       connect.setRequestMethod("GET");
       connect.setDoOutput(true);
       connect.setConnectTimeout(1000 * 10);
       connect.setReadTimeout(1000 * 80);
       conn.setRequestProperty("ContentType",  "application/x-www-form-urlencoded"); //采用通用的URL百分号编码的数据MIME类型来传参和设置请求头
       connect.setDoInput(true);
       // 连接
       connect.connect();
       // 发送数据
       connect.getOutputStream().write(request.getBytes(charset));
       // 接收数据
       int responseCode = connect.getResponseCode();
       if (responseCode == HttpURLConnection.HTTP_OK) {
       InputStream in = connect.getInputStream();
       byte[] data = new byte[1024];
       int len = 0;
       while ((len = in.read(data, 0, data.length)) != -1) {
              outStream.write(data, 0, len);
       }
              in.close();
       }
       // 关闭连接
       connect.disconnect();
       String response = outStream.toString("UTF-8");
       return response;
       }
}