[网络协议]java中http请求方法工具类（get/post）

import org.apache.http.conn.ConnectTimeoutException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.*;
import java.io.*;
import java.net.ConnectException;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.net.URLConnection;
import java.security.cert.X509Certificate;
public class HttpUtils {
    private static final Logger log = LoggerFactory.getLogger(HttpUtils.class);

    /**
     * 向指定 URL 发送GET方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendGet(String url, String param) {
        StringBuilder result = new StringBuilder();
        BufferedReader in = null;
        String urlNameString = url;
        try {
            if (param != null || param != "") {
                urlNameString = urlNameString + "?" + 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();
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result.append(line);
            }
        } catch (ConnectException e) {
            e.printStackTrace();
        } catch (SocketTimeoutException | ConnectTimeoutException e) {
            e.printStackTrace();
            //SocketTimeoutException：是Java包下抛出的异常，这定义了Socket读数据的超时时间，即从server获取响应数据须要等待的时间；当读取或者接收Socket超时会抛出SocketTimeoutException
            log.error("sendGet SocketTimeoutException, url=" + url + ",param=" + param, e);
        } catch (IOException e) {
            e.printStackTrace();
            log.error("sendGet IOException, url=" + url + ",param=" + param, e);
        } catch (Exception e) {
            e.printStackTrace();
            log.error("sendGet Exception, url=" + url + ",param=" + param, e);
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception ex) {
                ex.printStackTrace();
                log.error("sendGet Exception, url=" + url + ",param=" + param, ex);
            }
        }
        return result.toString();
    }

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        StringBuilder result = new StringBuilder();
        try {
            String urlNameString = url + "?" + param;
            log.info("sendPost - {}", urlNameString);
            URL realUrl = new URL(urlNameString);

            URLConnection conn = realUrl.openConnection();
            conn.setConnectTimeout(60000);  //连接主机的超时时间（单位：毫秒）
            conn.setReadTimeout(60000);     //从主机读取数据的超时时间（单位：毫秒）
            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.setRequestProperty("Accept-Charset", "utf-8");
            conn.setRequestProperty("contentType", "utf-8");
            //设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在http正文内，因此需要设为true, 默认情况下是false  发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            // 设置是否从httpUrlConnection读入，默认情况下是true;
            conn.setDoInput(true);
            // Post 请求不能使用缓存
            conn.setUseCaches(false);
            out = new PrintWriter(conn.getOutputStream());
            out.print(param);
            out.flush();
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result.append(line);
            }
//            log.info("recv - {}", result);
        } catch (ConnectException e) {
            log.error("调用HttpUtils.sendPost ConnectException, url=" + url + ",param=" + param, e);
        } catch (SocketTimeoutException | ConnectTimeoutException e) {
            //SocketTimeoutException：是Java包下抛出的异常，这定义了Socket读数据的超时时间，即从server获取响应数据须要等待的时间；当读取或者接收Socket超时会抛出SocketTimeoutException
            log.error("调用HttpUtils.sendPost SocketTimeoutException, url=" + url + ",param=" + param, e);
        } catch (IOException e) {
            log.error("调用HttpUtils.sendPost IOException, url=" + url + ",param=" + param, e);
        } catch (Exception e) {
            log.error("调用HttpsUtil.sendPost Exception, url=" + url + ",param=" + param, e);
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                log.error("调用HttpUtils.sendPost Exception, url=" + url + ",param=" + param, ex);
            }
        }
        return result.toString();
    }

}

以下提供java中经常会用到的http请求方法封装，提供的方法中，其参数拼接方式都是：

param1=value1&param2=value2 的形式，话不多说，直接上菜：