大家都知道HttpClient可以抓取頁面資料，但是有的頁面需要使用者登入後才可以訪問，第一次我用瀏覽器登入了，把瀏覽器的Cookie放了進去，可以抓取，但是一天後伺服器的Session就過期了，這樣很麻煩，後來在網上找了很多資料，才有了下面的版本，下面需要設定兩個URL，一個是登入頁的，主要是用來獲取登入後的Cookie，然後就可以請求第二次的URL了。程式碼很簡單應該大家都可以看懂，我就不解釋了。

package cn.amazon.http;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator
 
;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.CookieStore;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache
 
.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.PoolingClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

//對介面進行測試  
public class getCookie {
    private String loginUrl = ""
 
;
    private String SearchUrl = "";
    private String charset = "UTF-8";

    public void test() {
        //存放傳送引數
        Map<String, String> createMap = new HashMap<String, String>();
        createMap.put("userName", "");
        createMap.put("password", "");
        createMap.put("email", "[email protected]");
        HttpPost httpPost = null;
        HttpPost httpPost2 = null;
        HttpResponse response = null;
        DefaultHttpClient client = null;
        String result = null;
        try {
            client = new DefaultHttpClient(new PoolingClientConnectionManager());
            httpPost = new HttpPost(loginUrl);
            // 設定請求頭
            httpPost.setHeader("User-Agent",
                    "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0");
            // 設定引數
            List<NameValuePair> list = new ArrayList<NameValuePair>();
            Iterator iterator = createMap.entrySet().iterator();
            while (iterator.hasNext()) {
                Entry<String, String> elem = (Entry<String, String>) iterator.next();
                list.add(new BasicNameValuePair(elem.getKey(), elem.getValue()));
            }
            if (list.size() > 0) {
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);
                httpPost.setEntity(entity);
            }
            // 第一次請求
            response = client.execute(httpPost);
            System.out.println(response);
            // 第二次請求
            httpPost2 = new HttpPost(SearchUrl);
            response = client.execute(httpPost2);
            System.out.println(response);
            // 登入後的請求內容
            if (response != null) {
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    result = EntityUtils.toString(resEntity, charset);
                }
            }
            // System.out.println(result);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public static void main(String[] args) {
        getCookie main = new getCookie();
        main.test();
    }
}