java 后端请求第三方接口 包含post请求和get请求

public class HttpRequest {
    private static boolean debug = true;

　　//get请求
    public static String sendGet(String url, String param) {
        if (!debug) {
            return "";
        }
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);

            URLConnection connection = realUrl.openConnection();

            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent","Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");

            connection.connect();

            Map<String, List<String>> map = connection.getHeaderFields();

            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }

            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("异常" + e);
            e.printStackTrace();
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }
// [post请求]
    public static String sendPost(String url, String param) {
        if (!debug) {
            return "";
        }
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            URLConnection conn = realUrl.openConnection();
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("charset", "utf-8");
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            conn.setDoOutput(true);
            conn.setDoInput(true); 
            out = new PrintWriter(new OutputStreamWriter(conn.getOutputStream(), "utf-8"));
            out.print(param);
            out.flush();
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
            System.out.println("sendPost"+result);
        } catch (Exception e) {
            System.out.println("异常" + e);
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result;
    }
}

http请求测试工具类，请将请求地址，参数填写在main函数内