简单的利用UrlConnection，后台模拟http请求

来源：互联网发布：mac能下bilibili吗编辑：程序博客网时间：2024/05/16 07:15

这两天在整理看httpclient，然后想自己用UrlConnection后台模拟实现Http请求，于是一个简单的小例子就新鲜出炉了（支持代理哦）：

public class SimpleHttpTest {public static String send(String urlStr, Map<String,String> map,String encoding){String body="";StringBuffer sbuf = new StringBuffer();if(map!=null){for (Entry<String,String> entry : map.entrySet()) {sbuf.append(entry.getKey()).append("=").append(entry.getValue()).append("&");}if(sbuf.length()>0){sbuf.deleteCharAt(sbuf.length()-1);}} // 1、重新对请求报文进行 GBK 编码        byte[] postData = null;        try {            postData = sbuf.toString().getBytes(encoding);        } catch (UnsupportedEncodingException e) {        e.printStackTrace();        }        // 2、发送 HTTP(S) 请求        OutputStream reqStream = null;        InputStream resStream = null;        URLConnection request = null;        try {            System.out.println("交易请求地址：" + urlStr);            System.out.println("参数：" + sbuf.toString());                        //A、与服务器建立 HTTP(S) 连接    URL url = null;            try {            Proxy proxy = new Proxy(java.net.Proxy.Type.HTTP,new InetSocketAddress("127.0.0.1", 8087));                url = new URL(urlStr);                request = url.openConnection(proxy);                request.setDoInput(true);                request.setDoOutput(true);            } catch (MalformedURLException e) {            e.printStackTrace();            } catch (IOException e) {            e.printStackTrace();            }                        //B、指定报文头【Content-type】、【Content-length】 与 【Keep-alive】            request.setRequestProperty("Content-type", "application/x-www-form-urlencoded");            request.setRequestProperty("Content-length", String.valueOf(postData.length));            request.setRequestProperty("Keep-alive", "false");            request.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");                        //C、发送报文至服务器            reqStream = request.getOutputStream();            reqStream.write(postData);            reqStream.close();                        //D、接收服务器返回结果            ByteArrayOutputStream ms = null;            resStream = request.getInputStream();            ms = new ByteArrayOutputStream();            byte[] buf = new byte[4096];            int count;            while ((count = resStream.read(buf, 0, buf.length)) > 0) {                ms.write(buf, 0, count);            }            resStream.close();            body = new String(ms.toByteArray(), encoding);        } catch (UnknownHostException e) {            System.err.println( "服务器不可达【" + e.getMessage() + "】");        } catch (IOException e) {            e.printStackTrace();        } finally {            try {                if (reqStream != null)                reqStream.close();                if (resStream != null)                resStream.close();            } catch (Exception ex) {            }        }        System.out.println("交易响应结果：");        System.out.println(body);        return body;}public static void main(String[] args) {String url="http://php.weather.sina.com.cn/iframe/index/w_cl.php";Map<String, String> map = new HashMap<String, String>();map.put("code", "js");map.put("day", "0");map.put("city", "上海");map.put("dfc", "1");map.put("charset", "utf-8");send(url, map,"utf-8");}}

结果如下：

交易请求地址：http://php.weather.sina.com.cn/iframe/index/w_cl.php参数：dfc=1&charset=utf-8&day=0&code=js&city=上海交易响应结果：(function(){var w=[];w['上海']=[{s1:'阴',s2:'阴',f1:'yin',f2:'yin',t1:'17',t2:'14',p1:'≤3',p2:'≤3',d1:'东北风',d2:'东北风'}];var add={now:'2015-11-11 19:04:33',time:'1447239873',update:'北京时间11月11日17:10更新',error:'0',total:'1'};window.SWther={w:w,add:add};})();//0

代码中的步骤写的很明白了，如果你有心，还可以对该方法进行各种封装，方便使用。下篇我会分享一下httpclient是如何模拟后台来发送http请求的，还有配置ssl、代理、自定义header等等，敬请期待吧。

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