java 原生代码，不依赖库，http请求工具类，header使用

java 原生代码，不依赖库，

http请求工具类

package com.shiku.imserver.gpt;

import org.springframework.lang.Nullable;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

/**
 * http请求调用
 */
public class HttpURLConnectionUtil {
    /**
     * http get请求
     *
     * @param httpUrl 链接
     * @return 响应数据
     */
    public static String doGet(String httpUrl) {
        //链接
        HttpURLConnection connection = null;
        InputStream is = null;
        BufferedReader br = null;
        StringBuffer result = new StringBuffer();
        try {
            //创建连接
            URL url = new URL(httpUrl);
            connection = (HttpURLConnection) url.openConnection();
            //设置请求方式
            connection.setRequestMethod("GET");
            //设置连接超时时间
            connection.setConnectTimeout(15000);
            //设置读取超时时间
            connection.setReadTimeout(15000);
            //开始连接
            connection.connect();
            //获取响应数据
            if (connection.getResponseCode() == 200) {
                //获取返回的数据
                is = connection.getInputStream();
                if (is != null) {
                    br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                    String temp = null;
                    while ((temp = br.readLine()) != null) {
                        result.append(temp);
                    }
                }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            connection.disconnect();// 关闭远程连接
        }
        return result.toString();
    }

    /**
     * post请求
     *
     * @param httpUrl 链接
     * @param param   参数
     * @return
     */
    public static String doPost(String httpUrl, @Nullable String param, HashMap<String, Object> map) {
        StringBuffer result = new StringBuffer();
        //连接
        HttpURLConnection connection = null;
        OutputStream os = null;
        InputStream is = null;
        BufferedReader br = null;
        try {
            //创建连接对象
            URL url = new URL(httpUrl);
            //创建连接
            connection = (HttpURLConnection) url.openConnection();

            // 设置header
            for (Map.Entry item : map.entrySet()) {
                connection.setRequestProperty(item.getKey().toString(), item.getValue().toString());
            }

            //设置请求方法
            connection.setRequestMethod("POST");
            //设置连接超时时间
            connection.setConnectTimeout(15000);
            //设置读取超时时间
            connection.setReadTimeout(15000);
            //设置是否可读取
            connection.setDoOutput(true);
            //设置响应是否可读取
            connection.setDoInput(true);
            //设置参数类型
//            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            //拼装参数
            if (param != null && !param.equals("")) {
                //设置参数
                os = connection.getOutputStream();
                //拼装参数
                os.write(param.getBytes("UTF-8"));
            }
            //设置权限
            //设置请求头等
            //开启连接
            //connection.connect();
            //读取响应
            if (connection.getResponseCode() == 200) {
                is = connection.getInputStream();
                if (is != null) {
                    br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                    String temp = null;
                    if ((temp = br.readLine()) != null) {
                        result.append(temp);
                    }
                }
            }
            //关闭连接
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            //关闭连接
            connection.disconnect();
        }
        return result.toString();
    }

    public static void main(String[] str) {
        /*String result=HttpURLConnectionUtil.doGet("http://localhost:8080/test");
        System.out.println(result);*/
        /*Map<String, Object> map=new HashMap<>();
        map.put("1","1");
        map.put("2","2");
        map.put("3","3");
        System.out.println(HttpURLConnectionUtil.getParamStr(map));*/
    }
}