使用Post方法模拟登陆爬取网页的实现方法

import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.net.HttpURLConnection;import java.net.URL;import java.util.HashMap;public class test { //post请求地址 private static final String POST_URL = "";  //模拟谷歌浏览器请求 private static final String USER_AGENT = "";  //用账号登录某网站后 请求POST_URL链接获取cookie private static final String COOKIE = "";  //用账号登录某网站后 请求POST_URL链接获取数据包 private static final String REQUEST_DATA = "";  public static void main(String[] args) throws Exception {  HashMap<String, String> map = postCapture(REQUEST_DATA);  String responseCode = map.get("responseCode");  String value = map.get("value");    while(!responseCode.equals("200")){   map = postCapture(REQUEST_DATA);   responseCode = map.get("responseCode");   value = map.get("value");  }    //打印爬取结果  System.out.println(value); }  private static HashMap<String, String> postCapture(String requestData) throws Exception{  HashMap<String, String> map = new HashMap<>();    URL url = new URL(POST_URL);  HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();  httpConn.setDoInput(true); // 设置输入流采用字节流  httpConn.setDoOutput(true); // 设置输出流采用字节流  httpConn.setUseCaches(false); //设置缓存  httpConn.setRequestMethod("POST");//POST请求  httpConn.setRequestProperty("User-Agent", USER_AGENT);  httpConn.setRequestProperty("Cookie", COOKIE);    PrintWriter out = new PrintWriter(new OutputStreamWriter(httpConn.getOutputStream(), "UTF-8"));  out.println(requestData);  out.close();  int responseCode = httpConn.getResponseCode();  StringBuffer buffer = new StringBuffer();  if (responseCode == 200) {   BufferedReader reader = new BufferedReader(new InputStreamReader(httpConn.getInputStream(), "UTF-8"));   String line = null;   while ((line = reader.readLine()) != null) {    buffer.append(line);   }   reader.close();   httpConn.disconnect();  }    map.put("responseCode", new Integer(responseCode).toString());  map.put("value", buffer.toString());  return map; }}