import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class NetworkAPIUtils {
    /**
     * 发送GET请求
     * @param url 请求的URL
     * @return 响应结果
     * @throws IOException
     */
    public static String sendGetRequest(String url) throws IOException {
        String result = "";
        HttpURLConnection conn = null;
        InputStream is = null;
        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5000); // 设置连接超时
            conn.setReadTimeout(5000); // 设置读取超时
            conn.connect(); // 建立连接
            if (conn.getResponseCode() == 200) {
                is = conn.getInputStream();
                byte[] buffer = new byte[1024];
                int len = -1;
                while ((len = is.read(buffer)) != -1) {
                    result += new String(buffer, 0, len);
                }
            }
        } finally {
            if (is != null) {
                is.close();
            }
            if (conn != null) {
                conn.disconnect();
            }
        }
        return result;
    }

    /**
     * 发送POST请求
     * @param url 请求的URL
     * @param postData POST请求体数据
     * @return 响应结果
     * @throws IOException
     */
    public static String sendPostRequest(String url, String postData) throws IOException {
        String result = "";
        HttpURLConnection conn = null;
        InputStream is = null;
        try {
            conn = (HttpURLConnection) new URL(url).openConnection();
            conn.setRequestMethod("POST");
            conn.setConnectTimeout(5000); // 设置连接超时
            conn.setReadTimeout(5000); // 设置读取超时
            conn.setDoOutput(true); // 设置该连接是可以输出数据
            conn.setRequestProperty("Content-Type", "application/json"); // 设置请求头的内容类型
            conn.connect(); // 建立连接
            conn.getOutputStream().write(postData.getBytes()); // 发送POST请求体数据
            if (conn.getResponseCode() == 200) {
                is = conn.getInputStream();
                byte[] buffer = new byte[1024];
                int len = -1;
                while ((len = is.read(buffer)) != -1) {
                    result += new String(buffer, 0, len);
                }
            }
        } finally {
            if (is != null) {
                is.close();
            }
            if (conn != null) {
                conn.disconnect();
            }
        }
        return result;
    }
}

使用方法

try {
   // 发送GET请求
   String url1 = "https://webapi.domcer.com/match/mw";
   String response1 = NetworkAPIUtils.sendGetRequest(url1);
   System.out.println(response1);

   // 发送POST请求
   String url2 = "https://jsonplaceholder.typicode.com/posts";
   String postData = "{\"title\": \"foo\",\"body\": \"bar\",\"userId\": 1}";
   String response2 = NetworkAPIUtils.sendPostRequest(url2, postData);
   System.out.println(response2);
} catch (IOException e) {
       e.printStackTrace();
}