1、 对SharePreference的封装

import android.content.Context;import android.content.SharedPreferences;/** * 对SharePreference的封装 *  *  */public class PrefUtils {    public static void putBoolean(String key, boolean value, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        sp.edit().putBoolean(key, value).commit();    }    public static boolean getBoolean(String key, boolean defValue, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        return sp.getBoolean(key, defValue);    }    public static void putString(String key, String value, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        sp.edit().putString(key, value).commit();    }    public static String getString(String key, String defValue, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        return sp.getString(key, defValue);    }    public static void putInt(String key, int value, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        sp.edit().putInt(key, value).commit();    }    public static int getInt(String key, int defValue, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        return sp.getInt(key, defValue);    }    public static void remove(String key, Context ctx) {        SharedPreferences sp = ctx.getSharedPreferences("config",                Context.MODE_PRIVATE);        sp.edit().remove(key).commit();    }}

2、 网络缓存工具类

import android.content.Context;/** * 网络缓存工具类 * 原则: * 以url+参数为key, 以json为value,保存起来 *  */public class CacheUtils {    /**     * 写缓存     */    public static void setCache(String url, String json, Context ctx) {        //有时候,可以将缓存写在本地文件中, 以MD5(url)为文件名, 以json为文件内容保存        PrefUtils.putString(url, json, ctx);    }        /**     * 读缓存     */    public static String getCache(String url, Context ctx) {        //如果缓存写在文件中, 先找文件MD5(url)存不存在,如果存在,说明有缓存        return PrefUtils.getString(url, null, ctx);    }}

3、新闻中心示例

import java.util.ArrayList;import android.app.Activity;import android.text.TextUtils;import android.widget.Toast;import com.google.gson.Gson;import com.itheima.zhsh66.MainActivity;import com.itheima.zhsh66.base.BaseMenuDetailPager;import com.itheima.zhsh66.base.BasePager;import com.itheima.zhsh66.base.impl.menudetail.InteractMenuDetailPager;import com.itheima.zhsh66.base.impl.menudetail.NewsMenuDetailPager;import com.itheima.zhsh66.base.impl.menudetail.PhotosMenuDetailPager;import com.itheima.zhsh66.base.impl.menudetail.TopicMenuDetailPager;import com.itheima.zhsh66.domain.NewsMenuData;import com.itheima.zhsh66.global.Constants;import com.itheima.zhsh66.utils.CacheUtils;import com.lidroid.xutils.HttpUtils;import com.lidroid.xutils.exception.HttpException;import com.lidroid.xutils.http.ResponseInfo;import com.lidroid.xutils.http.callback.RequestCallBack;import com.lidroid.xutils.http.client.HttpRequest.HttpMethod;/** * 新闻中心 *  */public class NewsCenterPager extends BasePager {    // 菜单详情页集合    private ArrayList
      
        mMenuDetailPagers;    private NewsMenuData mNewsMenuData;// 新闻分类信息网络数据    public NewsCenterPager(Activity activity) {        super(activity);    }    @Override    public void initData() {        System.out.println("新闻中心初始化...");        tvTitle.setText("新闻");        // 1.首先先看本地有没有缓存        // 2.有缓存,直接加载缓存        String cache = CacheUtils.getCache(Constants.CATEGORIES_URL, mActivity);        if (!TextUtils.isEmpty(cache)) {            // 有缓存            System.out.println("发现缓存....");            processResult(cache);        }        // 即使发现有缓存,仍继续调用网络, 获取最新数据        getDataFromServer();    }    /**     * 从服务器获取数据 需要权限: 
            */    private void getDataFromServer() {        HttpUtils utils = new HttpUtils();        utils.send(HttpMethod.GET, Constants.CATEGORIES_URL,                new RequestCallBack
       
        () {                    @Override                    public void onSuccess(ResponseInfo
        
          responseInfo) {                        // 请求成功                        String result = responseInfo.result;// 获取json字符串                        // System.out.println("result:" + result);                        processResult(result);                        // 写缓存                        CacheUtils.setCache(Constants.CATEGORIES_URL, result,                                mActivity);                    }                    @Override                    public void onFailure(HttpException error, String msg) {                        // 请求失败                        error.printStackTrace();                        Toast.makeText(mActivity, msg, Toast.LENGTH_SHORT)                                .show();                    }                });    }    /**     * 解析json数据     *      * @param result     */    protected void processResult(String result) {        // gson->json        Gson gson = new Gson();        mNewsMenuData = gson.fromJson(result, NewsMenuData.class);        System.out.println("解析结果:" + mNewsMenuData);        // 获取侧边栏对象        MainActivity mainUI = (MainActivity) mActivity;        LeftMenuFragment leftMenuFragment = mainUI.getLeftMenuFragment();        // 将网络数据设置给侧边栏        leftMenuFragment.setData(mNewsMenuData.data);        // 初始化4个菜单详情页        mMenuDetailPagers = new ArrayList
         
          ();        mMenuDetailPagers.add(new NewsMenuDetailPager(mActivity,                mNewsMenuData.data.get(0).children));        mMenuDetailPagers.add(new TopicMenuDetailPager(mActivity));        mMenuDetailPagers.add(new PhotosMenuDetailPager(mActivity));        mMenuDetailPagers.add(new InteractMenuDetailPager(mActivity));        // 菜单详情页-新闻作为初始页面        setCurrentMenuDetailPager(0);    }    // 给新闻中心页面的FrameLayout填充布局    protected void setCurrentMenuDetailPager(int position) {        BaseMenuDetailPager pager = mMenuDetailPagers.get(position);        // 移除之前所有的view对象, 清理屏幕        flContent.removeAllViews();        flContent.addView(pager.mRootView);        pager.initData();// 初始化数据        // 更改标题        tvTitle.setText(mNewsMenuData.data.get(position).title);    }}