JAVA實現HTTP請求的方法
阿新 • • 發佈:2018-08-14
config auth AMM connect www 超時 port encoding n) 目前JAVA實現HTTP請求的方法用的最多的有兩種:
第一種是java原生HttpURLConnection
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.MalformedURLException; import java.net.URL; public class HttpClient { public static String doGet(String httpurl) { HttpURLConnection connection = null; InputStream is = null; BufferedReader br = null; String result = null;// 返回結果字符串 try { // 創建遠程url連接對象 URL url = new URL(httpurl); // 通過遠程url連接對象打開一個連接,強轉成httpURLConnection類 connection = (HttpURLConnection) url.openConnection(); // 設置連接方式:get connection.setRequestMethod("GET"); // 設置連接主機服務器的超時時間:15000毫秒 connection.setConnectTimeout(15000); // 設置讀取遠程返回的數據時間:60000毫秒 connection.setReadTimeout(60000); // 發送請求 connection.connect(); // 通過connection連接,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, "UTF-8")); // 存放數據 StringBuffer sbf = new StringBuffer(); String temp = null; while ((temp = br.readLine()) != null) { sbf.append(temp); sbf.append("\r\n"); } result = sbf.toString(); } } catch (MalformedURLException e) { e.printStackTrace(); } 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(); } } connection.disconnect();// 關閉遠程連接 } return result; } 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); // 通過遠程url連接對象打開連接 connection = (HttpURLConnection) url.openConnection(); // 設置連接請求方式 connection.setRequestMethod("POST"); // 設置連接主機服務器超時時間:15000毫秒 connection.setConnectTimeout(15000); // 設置讀取主機服務器返回數據超時時間:60000毫秒 connection.setReadTimeout(60000); // 默認值為:false,當向遠程服務器傳送數據/寫數據時,需要設置為true connection.setDoOutput(true); // 默認值為:true,當前向遠程服務讀取數據時,設置為true,該參數可有可無 connection.setDoInput(true); // 設置傳入參數的格式:請求參數應該是 name1=value1&name2=value2 的形式。 connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); // 設置鑒權信息:Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0 connection.setRequestProperty("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0"); // 通過連接對象獲取一個輸出流 os = connection.getOutputStream(); // 通過輸出流對象將參數寫出去/傳輸出去,它是通過字節數組寫出的 os.write(param.getBytes()); // 通過連接對象獲取一個輸入流,向遠程讀取 if (connection.getResponseCode() == 200) { is = connection.getInputStream(); // 對輸入流對象進行包裝:charset根據工作項目組的要求來設置 br = new BufferedReader(new InputStreamReader(is, "UTF-8")); StringBuffer sbf = new StringBuffer(); String temp = null; // 循環遍歷一行一行讀取數據 while ((temp = br.readLine()) != null) { sbf.append(temp); sbf.append("\r\n"); } result = sbf.toString(); } } catch (MalformedURLException e) { e.printStackTrace(); } 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(); } } // 斷開與遠程地址url的連接 connection.disconnect(); } return result; } }
第二種是apache httpClient4.5
import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import org.apache.http.HttpEntity; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.config.RequestConfig; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils; public class HttpClient4 { public static String doGet(String url) { CloseableHttpClient httpClient = null; CloseableHttpResponse response = null; String result = ""; try { // 通過址默認配置創建一個httpClient實例 httpClient = HttpClients.createDefault(); // 創建httpGet遠程連接實例 HttpGet httpGet = new HttpGet(url); // 設置請求頭信息,鑒權 httpGet.setHeader("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0"); // 設置配置請求參數 RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 連接主機服務超時時間 .setConnectionRequestTimeout(35000)// 請求超時時間 .setSocketTimeout(60000)// 數據讀取超時時間 .build(); // 為httpGet實例設置配置 httpGet.setConfig(requestConfig); // 執行get請求得到返回對象 response = httpClient.execute(httpGet); // 通過返回對象獲取返回數據 HttpEntity entity = response.getEntity(); // 通過EntityUtils中的toString方法將結果轉換為字符串 result = EntityUtils.toString(entity); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { // 關閉資源 if (null != response) { try { response.close(); } catch (IOException e) { e.printStackTrace(); } } if (null != httpClient) { try { httpClient.close(); } catch (IOException e) { e.printStackTrace(); } } } return result; } public static String doPost(String url, Map<String, Object> paramMap) { CloseableHttpClient httpClient = null; CloseableHttpResponse httpResponse = null; String result = ""; // 創建httpClient實例 httpClient = HttpClients.createDefault(); // 創建httpPost遠程連接實例 HttpPost httpPost = new HttpPost(url); // 配置請求參數實例 RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 設置連接主機服務超時時間 .setConnectionRequestTimeout(35000)// 設置連接請求超時時間 .setSocketTimeout(60000)// 設置讀取數據連接超時時間 .build(); // 為httpPost實例設置配置 httpPost.setConfig(requestConfig); // 設置請求頭 httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded"); // 封裝post請求參數 if (null != paramMap && paramMap.size() > 0) { List<NameValuePair> nvps = new ArrayList<NameValuePair>(); // 通過map集成entrySet方法獲取entity Set<Entry<String, Object>> entrySet = paramMap.entrySet(); // 循環遍歷,獲取叠代器 Iterator<Entry<String, Object>> iterator = entrySet.iterator(); while (iterator.hasNext()) { Entry<String, Object> mapEntry = iterator.next(); nvps.add(new BasicNameValuePair(mapEntry.getKey(), mapEntry.getValue().toString())); } // 為httpPost設置封裝好的請求參數 try { httpPost.setEntity(new UrlEncodedFormEntity(nvps, "UTF-8")); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } try { // httpClient對象執行post請求,並返回響應參數對象 httpResponse = httpClient.execute(httpPost); // 從響應對象中獲取響應內容 HttpEntity entity = httpResponse.getEntity(); result = EntityUtils.toString(entity); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { // 關閉資源 if (null != httpResponse) { try { httpResponse.close(); } catch (IOException e) { e.printStackTrace(); } } if (null != httpClient) { try { httpClient.close(); } catch (IOException e) { e.printStackTrace(); } } } return result; } }
有時候我們在使用post請求時,可能傳入的參數是json或者其他格式,此時我們則需要更改請求頭及參數的設置信息,以httpClient4.5為例,更改下面兩列配置:httpPost.setEntity(new StringEntity("你的json串")); httpPost.addHeader("Content-Type", "application/json")。
JAVA實現HTTP請求的方法