java http請求

/**
     * 向指定URL發送GET方法的請求
     * 
     * @param url
     *            發送請求的URL
     * @param param
     *            請求參數，請求參數是 string 類型。
     * @return URL 所表明遠程資源的響應結果
     */
    public static String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            URL realUrl = new URL(urlNameString);
            // 打開和URL之間的鏈接
            URLConnection connection = realUrl.openConnection();
            // 設置通用的請求屬性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 創建實際的鏈接
            connection.connect();
            // 獲取全部響應頭字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍歷全部的響應頭字段
            for (String key : map.keySet()) {
                System.out.println(key + "--->" + map.get(key));
            }
            // 定義 BufferedReader輸入流來讀取URL的響應
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("發送GET請求出現異常！" + e);
            e.printStackTrace();
        }
        // 使用finally塊來關閉輸入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    } 
/**
     * 發送POST請求
     * @param url 目的地址
     * @param parameters 請求參數，Map類型。
     * @return 遠程響應結果
     */
    public static String sendPost(String url, Map<String, String> parameters) {
        String result = "";// 返回的結果  
        BufferedReader in = null;// 讀取響應輸入流  
        PrintWriter out = null;
        StringBuffer sb = new StringBuffer();// 處理請求參數  
        String params = "";// 編碼以後的參數

        try {
            // 編碼請求參數  
            if (parameters.size() == 1) {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8"));
                }
                params = sb.toString();
            } else {
                for (String name : parameters.keySet()) {
                    sb.append(name).append("=").append(
                            java.net.URLEncoder.encode(parameters.get(name),
                                    "UTF-8")).append("&");
                }
                String temp_params = sb.toString();
                params = temp_params.substring(0, temp_params.length() - 1);
            }
            // 建立URL對象  
            java.net.URL connURL = new java.net.URL(url);
            // 打開URL鏈接  
            java.net.HttpURLConnection httpConn = (java.net.HttpURLConnection) connURL
                    .openConnection();
            // 設置通用屬性  
            httpConn.setRequestProperty("Accept", "*/*");
            httpConn.setRequestProperty("Connection", "Keep-Alive");
            httpConn.setRequestProperty("User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1)");
            // 設置POST方式  
            httpConn.setDoInput(true);
            httpConn.setDoOutput(true);
            // 獲取HttpURLConnection對象對應的輸出流  
            out = new PrintWriter(httpConn.getOutputStream());
            // 發送請求參數  
            out.write(params);
            // flush輸出流的緩衝  
            out.flush();
            // 定義BufferedReader輸入流來讀取URL的響應，設置編碼方式  
            in = new BufferedReader(new InputStreamReader(httpConn
                    .getInputStream(), "UTF-8"));
            String line;
            // 讀取返回的內容  
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        System.out.println("數據發送成功");
        return result;
    }
    
/**
     * 向指定 URL 發送POST方法的請求
     * @param url發送請求的 URL
     * @param param請求參數，請求參數是 string 類型。
     * @return 所表明遠程資源的響應結果
     */

    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打開和URL之間的鏈接
            URLConnection conn = realUrl.openConnection();
            // 設置通用的請求屬性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 發送POST請求必須設置以下兩行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 獲取URLConnection對象對應的輸出流
            out = new PrintWriter(conn.getOutputStream());
            // 發送請求參數
            out.print(param);
            // flush輸出流的緩衝
            out.flush();
            // 定義BufferedReader輸入流來讀取URL的響應
            in = new BufferedReader(
                    new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("發送 POST 請求出現異常！"+e);
            e.printStackTrace();
        }
        //使用finally塊來關閉輸出流、輸入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }