本文實例講解了java實現http的Post、Get、代理訪問請求的詳細代碼片段，分享給大家供大家參考，具體內容如下
package com.snowfigure.kits.net; import java.io.BufferedReader; import java.io.IOException;import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStreamWriter;import java.io.UnsupportedEncodingException; import java.net.HttpURLConnection; import java.net.InetSocketAddress;import java.net.Proxy;import java.net.URL; import java.net.URLConnection;import java.util.List;import java.util.Map; /** * Http請求工具類* @author snowfigure * @since 2014-8-24 13:30:56 * @version v1.0.1 */public class HttpRequestUtil { static boolean proxySet = false; static String proxyHost = "127.0.0.1"; static int proxyPort = 8087; /** * 編碼* @param source * @return */ public static String urlEncode(String source,String encode) { String result = source; try { result = java.net.URLEncoder.encode(source,encode); } catch (UnsupportedEncodingException e) { e.printStackTrace(); return "0"; } return result; } public static String urlEncodeGBK(String source) { String result = source; try { result = java.net.URLEncoder.encode(source,"GBK"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); return "0"; } return result; } /** * 發起http請求獲取返回結果* @param req_url 請求地址* @return */ public static String httpRequest(String req_url) { StringBuffer buffer = new StringBuffer(); try { URL url = new URL(req_url); HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection(); httpUrlConn.setDoOutput(false); httpUrlConn.setDoInput(true); httpUrlConn.setUseCaches(false); httpUrlConn.setRequestMethod("GET"); httpUrlConn.connect(); // 將返回的輸入流轉換成字符串InputStream inputStream = httpUrlConn.getInputStream(); InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8"); BufferedReader bufferedReader = new BufferedReader(inputStreamReader); String str = null; while ((str = bufferedReader.readLine()) != null) { buffer.append(str); } bufferedReader.close(); inputStreamReader.close(); // 釋放資源inputStream.close(); inputStream = null; httpUrlConn.disconnect(); } catch (Exception e) { System.out.println(e.getStackTrace()); } return buffer.toString(); } /** * 發送http請求取得返回的輸入流* @param requestUrl 請求地址* @return InputStream */ public static InputStream httpRequestIO(String requestUrl) { InputStream inputStream = null; try { URL url = new URL(requestUrl); HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection(); httpUrlConn.setDoInput(true); httpUrlConn.setRequestMethod("GET"); httpUrlConn.connect(); // 獲得返回的輸入流inputStream = httpUrlConn.getInputStream(); } catch (Exception e) { e.printStackTrace(); } return inputStream; } /** * 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，請求參數應該是name1=value1&name2=value2 的形式。 * @return URL 所代表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之間的連接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)"); // 建立實際的連接connection.connect(); // 獲取所有響應頭字段Map<String, List<String>> map = connection.getHeaderFields(); // 遍歷所有的響應頭字段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; } /** * 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，請求參數應該是name1=value1&name2=value2 的形式。 * @param isproxy * 是否使用代理模式* @return 所代表遠程資源的響應結果*/ public static String sendPost(String url, String param,boolean isproxy) { OutputStreamWriter out = null; BufferedReader in = null; String result = ""; try { URL realUrl = new URL(url); HttpURLConnection conn = null; if(isproxy){//使用代理模式@SuppressWarnings("static-access") Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort)); conn = (HttpURLConnection) realUrl.openConnection(proxy); }else{ conn = (HttpURLConnection) realUrl.openConnection(); } // 打開和URL之間的連接// 發送POST請求必須設置如下兩行conn.setDoOutput(true); conn.setDoInput(true); conn.setRequestMethod("POST"); // POST方法// 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)"); conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); conn.connect(); // 獲取URLConnection對像對應的輸出流out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8"); // 發送請求參數out.write(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; } public static void main(String[] args) { //demo:代理訪問String url = "http://api.adf.ly/api.php"; String para = "key=youkeyid&youuid=uid&advert_type=int&domain=adf.ly&url=http://somewebsite.com"; String sr=HttpRequestUtil.sendPost(url,para,true); System.out.println(sr); } }希望本文所述對大家學習java程序設計有所幫助。