使用Post方法模擬登陸爬取網頁
最近弄爬蟲,遇到的一個問題就是如何使用post方法模擬登陸爬取網頁。下面是極簡版的代碼:
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請求地址 private static final String POST_URL = ""; //模擬谷歌瀏覽器請求 private static final String USER_AGENT = ""; //用賬號登錄某網站后 請求POST_URL鏈接獲取cookie private static final String COOKIE = ""; //用賬號登錄某網站后 請求POST_URL鏈接獲取數據包 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"); } //打印爬取結果 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); // 設置輸入流采用字節流 httpConn.setDoOutput(true); // 設置輸出流采用字節流 httpConn.setUseCaches(false); //設置緩存 httpConn.setRequestMethod("POST");//POST請求 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; } }