本文实例讲解了java实现http的Post、Get、代理访问请求的详细代码片段，分享给大家供大家参考，具体内容如下

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请求工具类 * @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; /** * 编码 * @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; } /** * 发起http请求获取返回结果 * @param req_url 请求地址 * @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(); // 将返回的输入流转换成字符串 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(); // 释放资源 inputStream.close(); inputStream = null; httpUrlConn.disconnect(); } catch (Exception e) { System.out.println(e.getStackTrace()); } return buffer.toString(); } /** * 发送http请求取得返回的输入流 * @param requestUrl 请求地址 * @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(); // 获得返回的输入流 inputStream = httpUrlConn.getInputStream(); } catch (Exception e) { e.printStackTrace(); } return inputStream; } /** * 向指定URL发送GET方法的请求 * * @param url * 发送请求的URL * @param param * 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 * @return URL 所代表远程资源的响应结果 */ public static String sendGet(String url, String param) { String result = ""; BufferedReader in = null; try { String urlNameString = url + "?" + param; URL realUrl = new URL(urlNameString); // 打开和URL之间的连接 URLConnection connection = realUrl.openConnection(); // 设置通用的请求属性 connection.setRequestProperty("accept", "*/*"); connection.setRequestProperty("connection", "Keep-Alive"); connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); // 建立实际的连接 connection.connect(); // 获取所有响应头字段 Map<String, List<String>> map = connection.getHeaderFields(); // 遍历所有的响应头字段 for (String key : map.keySet()) { System.out.println(key + "--->" + map.get(key)); } // 定义 BufferedReader输入流来读取URL的响应 in = new BufferedReader(new InputStreamReader( connection.getInputStream())); String line; while ((line = in.readLine()) != null) { result += line; } } catch (Exception e) { System.out.println("发送GET请求出现异常！" + e); e.printStackTrace(); } // 使用finally块来关闭输入流 finally { try { if (in != null) { in.close(); } } catch (Exception e2) { e2.printStackTrace(); } } return result; } /** * 向指定 URL 发送POST方法的请求 * * @param url * 发送请求的 URL * @param param * 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 * @param isproxy * 是否使用代理模式 * @return 所代表远程资源的响应结果 */ 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(); } // 打开和URL之间的连接 // 发送POST请求必须设置如下两行 conn.setDoOutput(true); conn.setDoInput(true); conn.setRequestMethod("POST"); // POST方法 // 设置通用的请求属性 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-"; String sr=HttpRequestUtil.sendPost(url,para,true); System.out.println(sr); } }

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