java 發送http請求

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package com.service; import java.io.BufferedReader; import java.io.DataOutputStream; import java.io.IOException; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLEncoder; public class HttpInvoker {         public static final String GET_URL = " http://localhost:8080/demo/  ";         public static final String POST_URL = " http://localhost:8080/demo/  ";         public static void readContentFromGet() throws IOException {                // 拼湊get請求的URL字串，使用URLEncoder.encode對特殊和不可見字元進行編碼                String getURL = GET_URL + " ?username= "                                + URLEncoder.encode("fat man", " utf-8 ");                URL getUrl = new URL(getURL);                // 根據拼湊的URL，開啟串連，URL.openConnection()函數會根據 URL的類型，返回不同的URLConnection子類的對象，在這裡我們的URL是一個http，因此它實際上返回的是HttpURLConnection                HttpURLConnection connection = (HttpURLConnection) getUrl.openConnection();                // 建立與伺服器的串連，並未發送資料                connection.connect();                // 發送資料到伺服器並使用Reader讀取返回的資料                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));                System.out.println(" ============================= ");                System.out.println(" Contents of get request ");                System.out.println(" ============================= ");                String lines;                while ((lines = reader.readLine()) != null) {                        System.out.println(lines);                }                reader.close();                // 中斷連線                connection.disconnect();                System.out.println(" ============================= ");                System.out.println(" Contents of get request ends ");                System.out.println(" ============================= ");         }         public static void readContentFromPost() throws IOException {                // Post請求的url，與get不同的是不需要帶參數                URL postUrl = new URL(POST_URL);                // 開啟串連                HttpURLConnection connection = (HttpURLConnection) postUrl.openConnection();                //開啟讀寫屬性，預設均為false                connection.setDoOutput(true);                 　　　　　　　 connection.setDoInput(true);                // 佈建要求方式，預設為GET                connection.setRequestMethod(" POST ");                // Post 請求不能使用緩衝                connection.setUseCaches(false);                // URLConnection.setFollowRedirects是static 函數，作用於所有的URLConnection對象。                // connection.setFollowRedirects(true);                //URLConnection.setInstanceFollowRedirects 是成員函數，僅作用於當前函數                connection.setInstanceFollowRedirects(true);                // 配置串連的Content-type，配置為application/x- www-form-urlencoded的意思是本文是urlencoded編碼過的form參數，下面我們可以看到我們對本文內容使用URLEncoder.encode進行編碼                connection.setRequestProperty(" Content-Type ",                                " application/x-www-form-urlencoded ");                // 串連，從postUrl.openConnection()至此的配置必須要在 connect之前完成，                // 要注意的是connection.getOutputStream()會隱含的進行調用 connect()，所以這裡可以省略                //connection.connect();                DataOutputStream out = new DataOutputStream(connection.getOutputStream());                //本文內容其實跟get的URL中‘?‘後的參數字串一致                String content = " firstname= "+URLEncoder.encode(" 一個大肥人 ", " utf-8 ");                // DataOutputStream.writeBytes將字串中的16位的 unicode字元以8位的字元形式寫道流裡面                out.writeBytes(content);                out.flush();                out.close(); // flush and close                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));                String line;                System.out.println(" ============================= ");                System.out.println(" Contents of post request ");                System.out.println(" ============================= ");                while ((line = reader.readLine()) != null) {                        System.out.println(line);                }                System.out.println(" ============================= ");                System.out.println(" Contents of post request ends ");                System.out.println(" ============================= ");                reader.close();                //connection.disconnect();         }         public static void main(String[] args) {                // TODO Auto-generated method stub                try {                        readContentFromGet();                        readContentFromPost();                } catch (IOException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                }         } } 

 

java 發送http請求