android DefaultHttpClient设置setCookieStore

android DefaultHttpClient设置setCookieStore
第一步：设置CookieStoreUtils的工具类

import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.http.client.CookieStore;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.cookie.BasicClientCookie;

import android.app.Activity;
import android.content.SharedPreferences;

import com.google.gson.Gson;

public class CookieStoreUtils {

    @SuppressWarnings("unchecked")
    public static CookieStore initCookieStore(CookieStore cookieStore){
        SharedPreferences mySharedPreferences = MyApplication.mInstance.getSharedPreferences(
                "cookies", Activity.MODE_PRIVATE);
        Map<String, String> map = (Map<String, String>) mySharedPreferences.getAll();
        if (map != null) {
            Iterator<String> it = map.keySet().iterator();
            Gson gson = new Gson();
            while (it.hasNext()) {
                String key = it.next();
                String jsonCookie = map.get(key);
                if (jsonCookie != null) {       
                    BasicClientCookie cookie = gson.fromJson(jsonCookie, BasicClientCookie.class);  
                    cookieStore.addCookie(cookie);
                }
            }
        }
        return cookieStore;
    }

    public static void saveCookies(List<Cookie> cookies){
        SharedPreferences mySharedPreferences = MyApplication.mInstance.getSharedPreferences("cookies", Activity.MODE_PRIVATE);
        SharedPreferences.Editor editor = mySharedPreferences.edit();
        Gson gson = new Gson();
        for(Cookie cookie:cookies){
            editor.putString(cookie.getName(), gson.toJson(cookie));// JSON转换成String类型
        }
        editor.commit();
    }

}

private static CookieStore cookieStore = null;

  /*
     * POST方式，查询从URL得到的字符串
     */
    public static String queryStringForPost(String url, List<NameValuePair> params) {
        DefaultHttpClient client = new DefaultHttpClient();
        if(cookieStore==null){
            cookieStore = CookieStoreUtils.initCookieStore(client.getCookieStore());
        }
        client.setCookieStore(cookieStore); 
        // 获取HttpPost对象
        HttpPost httpPost = new HttpPost(url);
        String result = "isError";

        HttpResponse httpResponse = null;
        try {
            // 设置HttpPost请求参数
            httpPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
            httpResponse = client.execute(httpPost);

            if (httpResponse.getStatusLine().getStatusCode() == 200) {
                result = EntityUtils.toString(httpResponse.getEntity());
                if (result.equals("{"data":null}") || result.equals("{"data":[]}")) {// 如果后台数据为空
                    return "isNull";// 返回为空的结果
                }
            }
            //保存cookie到本地
            CookieStoreUtils.saveCookies(cookieStore.getCookies());
            return result;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return result;
    }