Java主流的Http请求--原生的HttpURLConnection

import com.alibaba.fastjson.JSONObject;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.ParseException;

public class get_post {

    /**
     * Created by chengxia on 2018/12/4.
     */
        public String doPost(String URL){
            OutputStreamWriter out = null;
            BufferedReader in = null;
            StringBuilder result = new StringBuilder();
            HttpURLConnection conn = null;
            try{
                URL url = new URL(URL);
                conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("POST");
                //发送POST请求必须设置为true
                conn.setDoOutput(true);
                conn.setDoInput(true);
                //设置连接超时时间和读取超时时间
                conn.setConnectTimeout(30000);
                conn.setReadTimeout(10000);
                conn.setRequestProperty("Content-Type", "application/json");
                conn.setRequestProperty("Accept", "application/json");
                //获取输出流
                out = new OutputStreamWriter(conn.getOutputStream());
                //向post请求发送json数据
                String jsonStr = "{"touser":"", "msgtype":"text",  "text":{" +
                        " "content":""}}";
                out.write(jsonStr);
                out.flush();
                out.close();
                //取得输入流，并使用Reader读取
                if (200 == conn.getResponseCode()){
                    in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
                    String line;
                    while ((line = in.readLine()) != null){
                        result.append(line);
                        System.out.println(line);
                    }
                }else{
                    System.out.println("ResponseCode is an error code:" + conn.getResponseCode());
                }
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                try{
                    if(out != null){
                        out.close();
                    }
                    if(in != null){
                        in.close();
                    }
                }catch (IOException ioe){
                    ioe.printStackTrace();
                }
            }
            return result.toString();
        }

        public String doGet(String URL){
            HttpURLConnection conn = null;
            InputStream is = null;
            BufferedReader br = null;
            StringBuilder result = new StringBuilder();
            try{
                //创建远程url连接对象
                URL url = new URL(URL);
                //通过远程url连接对象打开一个连接，强转成HTTPURLConnection类
                conn = (HttpURLConnection) url.openConnection();
                conn.setRequestMethod("GET");
                //设置连接超时时间和读取超时时间
                conn.setConnectTimeout(15000);
                conn.setReadTimeout(60000);
                conn.setRequestProperty("Accept", "application/json");
                //发送请求
                conn.connect();
                //通过conn取得输入流，并使用Reader读取
                if (200 == conn.getResponseCode()){
                    is = conn.getInputStream();
                    br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                    String line;
                    while ((line = br.readLine()) != null){
                        result.append(line);
//                        System.out.println(line);
                    }
                    //json类型字符串转为jsonObject
//                    System.out.println(result);
                    JSONObject jsonObject = JSONObject.parseObject(String.valueOf(result));
                    //根据key值获取数据value
                    System.out.println(jsonObject.getString("access_token"));  //输出value1
                    Writer writer = null;
                    StringBuilder outputString = new StringBuilder();
                    try {
                        outputString.append(jsonObject.getString("access_token") + "
");
                        writer = new FileWriter("test.txt"); // true表示追加
                        writer.write(outputString.toString());
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        try {
                            writer.close();
                        } catch (IOException e2) {
                            e2.printStackTrace();
                        }
                    }



                }else{
                    System.out.println("ResponseCode is an error code:" + conn.getResponseCode());
                }
            }catch (MalformedURLException e){
                e.printStackTrace();
            }catch (IOException e){
                e.printStackTrace();
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                try{
                    if(br != null){
                        br.close();
                    }
                    if(is != null){
                        is.close();
                    }
                }catch (IOException ioe){
                    ioe.printStackTrace();
                }
                conn.disconnect();
            }
            return result.toString();
        }


    /** 读取文件数据，存入集合中
     * @return*/
    public static String readtFile(File file) throws IOException, ParseException {
        InputStreamReader read = null;// 考虑到编码格式
        try {
            read = new InputStreamReader(new FileInputStream(file), "utf-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        BufferedReader bufferedReader = new BufferedReader(read);
        String lineTxt = null;
        StringBuffer buffer = new StringBuffer();
        String line = " ";
        while ((line = bufferedReader.readLine()) != null) {
//            System.out.println(lineTxt);
            buffer.append(line);
        }

        read.close();
        return buffer.toString();
    }


   public static void main(String[] args) throws Exception {
             get_post http = new get_post();

//            System.out.println("Testing 1 - Do Http GET request");
       //获取token的get方法
//            http.doGet("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=&secret=");

            System.out.println("
Testing 2 - Do Http POST request");
            File file = new File("test.txt");
            String token = readtFile(file);
            System.out.println(token);
            http.doPost("https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token="+token);

        }

    }