使用UrlConnection实现后台模拟http请求的简单实例

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使用UrlConnection实现后台模拟http请求的简单实例

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 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();
}

  1. // 2、发送 HTTP(S) 请求
  2. OutputStream reqStream = null;
  3. InputStream resStream = null;
  4. URLConnection request = null;
  5. try {
  6. System.out.println("交易请求地址:" + urlStr);
  7. System.out.println("参数:" + sbuf.toString());
  8. //A、与服务器建立 HTTP(S) 连接
  9. URL url = null;
  10. try {
  11. Proxy proxy = new Proxy(java.net.Proxy.Type.HTTP,new InetSocketAddress("127.0.0.1",8087));
  12. url = new URL(urlStr);
  13. request = url.openConnection(proxy);
  14. request.setDoInput(true);
  15. request.setDoOutput(true);
  16. } catch (MalformedURLException e) {
  17. e.printStackTrace();
  18. } catch (IOException e) {
  19. e.printStackTrace();
  20. }
  21. //B、指定报文头【Content-type】、【Content-length】 与 【Keep-alive】
  22. request.setRequestProperty("Content-type","application/x-www-form-urlencoded");
  23. request.setRequestProperty("Content-length",String.valueOf(postData.length));
  24. request.setRequestProperty("Keep-alive","false");
  25. request.setRequestProperty("User-Agent","Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
  26. //C、发送报文至服务器
  27. reqStream = request.getOutputStream();
  28. reqStream.write(postData);
  29. reqStream.close();
  30. //D、接收服务器返回结果
  31. ByteArrayOutputStream ms = null;
  32. resStream = request.getInputStream();
  33. ms = new ByteArrayOutputStream();
  34. byte[] buf = new byte[4096];
  35. int count;
  36. while ((count = resStream.read(buf,buf.length)) > 0) {
  37. ms.write(buf,count);
  38. }
  39. resStream.close();
  40. body = new String(ms.toByteArray(),encoding);
  41. } catch (UnknownHostException e) {
  42. System.err.println( "服务器不可达【" + e.getMessage() + "】");
  43. } catch (IOException e) {
  44. e.printStackTrace();
  45. } finally {
  46. try {
  47. if (reqStream != null)
  48. reqStream.close();
  49. if (resStream != null)
  50. resStream.close();
  51. } catch (Exception ex) {
  52. }
  53. }
  54. System.out.println("交易响应结果:");
  55. System.out.println(body);
  56. 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:

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。

感谢阅读,希望能帮助到大家,谢谢大家对本站的支持

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