Java實現Http請求

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;

/**
 * @title: HttpClient類實現Get、Post方法
 * @author: 獵手部落
 * @date: 2020年11月18日 16:00
 * @description: 備忘
 */
public class HttpClient {

    //GET方法
    public static String doGet(String httpurl) {

        HttpURLConnection connection = null;
        InputStream is = null;
        BufferedReader br = null;
        String result = null; //返回結果字串

        try {
            //建立遠端url連線物件
            URL url = new URL(httpurl);

            //透過遠端url連線物件開啟一個連線，強轉成httpURLConnection類
            connection = (HttpURLConnection) url.openConnection();

            //設定連線方式：get
            connection.setRequestMethod("GET");

            //設定連線主機伺服器的超時時間：15000毫秒
            connection.setConnectTimeout(15000);

            //設定讀取遠端返回的資料時間：60000毫秒
            connection.setReadTimeout(60000);

            //傳送請求
            connection.connect();

            //透過connection連線，獲取輸入流
            if (connection.getResponseCode() == 200) {

                is = connection.getInputStream();

                //封裝輸入流is，並指定字符集
                br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));

                //存放資料
                StringBuilder sb = new StringBuilder();
                String line;

                while ((line = br.readLine()) != null) {
                    sb.append(line);
                    sb.append("\r\n");
                }
                result = sb.toString();
            }

        } catch (IOException e) {
            e.printStackTrace();

        } finally {

            //關閉資源
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (null != is) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            assert connection != null;
            connection.disconnect(); //關閉遠端連線
        }

        return result;
    }

    //POST方法
    public static String doPost(String httpUrl, String param) {

        HttpURLConnection connection = null;
        InputStream is = null;
        OutputStream os = null;
        BufferedReader br = null;
        String result = null;

        try {
            URL url = new URL(httpUrl);

            //透過遠端url連線物件開啟連線
            connection = (HttpURLConnection) url.openConnection();

            //設定連線請求方式
            connection.setRequestMethod("POST");

            //設定連線主機伺服器超時時間：15000毫秒
            connection.setConnectTimeout(15000);

            //設定讀取主機伺服器返回資料超時時間：60000毫秒
            connection.setReadTimeout(60000);

            //預設值為：false，當向遠端伺服器傳送資料/寫資料時，需要設定為true
            connection.setDoOutput(true);

            //預設值為：true，當前向遠端服務讀取資料時，設定為true，該引數可有可無
            connection.setDoInput(true);

            //設定傳入引數的格式:請求引數應該是 name1=value1&name2=value2 的形式。
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            //設定鑑權資訊：Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0
            connection.setRequestProperty("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");

            //透過連線物件獲取一個輸出流
            os = connection.getOutputStream();

            //透過輸出流物件將引數寫出去/傳輸出去,它是透過位元組陣列寫出的
            os.write(param.getBytes());

            //透過連線物件獲取一個輸入流，向遠端讀取
            if (connection.getResponseCode() == 200) {

                is = connection.getInputStream();

                //對輸入流物件進行包裝:charset根據工作專案組的要求來設定
                br = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));

                StringBuilder sb = new StringBuilder();
                String line;

                //迴圈遍歷一行一行讀取資料
                while ((line = br.readLine()) != null) {
                    sb.append(line);
                    sb.append("\r\n");
                }
                result = sb.toString();
            }

        } catch (IOException e) {
            e.printStackTrace();

        } finally {

            //關閉資源
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (null != os) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (null != is) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            //斷開與遠端地址url的連線
            assert connection != null;
            connection.disconnect();
        }

        return result;
    }
}