咨询项目实战月考练习

其他 2018-06-24 12:13:14 阅读次数: 0 
  MainActivity页面
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
import android.widget.Toast;
import com.google.gson.Gson;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshListView;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private PullToRefreshListView plv;
    private int pageIndex=1;
    private String webUrl="https://api.tianapi.com/wxnew/?key=48a7d7193e11bd2dd4a683b6e2f90a4f&num=10&page="+pageIndex;
    //定义一个大集合
    private List<ResultData.NewslistBean> dataAll=new ArrayList<>();
    private  MyAdapter adapter;
    private int operType=1;//1:代表刷新 2：代表加载更多

    private Handler myHanlder=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            List<ResultData.NewslistBean> lists=( List<ResultData.NewslistBean>)msg.obj;

            //显示数据
            showData(lists);

        }
    };

    private JsonCacheDao jsonCacheDao;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        plv= findViewById(R.id.plv);

        jsonCacheDao = new JsonCacheDao(this);
        initPlv();

        requestNetData();

    }

    private void requestNetData() {
        if (NetStateUtil.isConn(this)){
            new Thread(){
                @Override
                public void run() {
                    try {
                        URL url=new URL(webUrl);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.setRequestMethod("GET");
                        connection.setConnectTimeout(5000);
                        connection.setReadTimeout(5000);
                        int responseCode = connection.getResponseCode();
                        if(responseCode==200){
                            InputStream stream = connection.getInputStream();
                            String s = stremToString(stream);
                            jsonCacheDao.insertData(webUrl,s);
                            List<ResultData.NewslistBean> newslist = asyncJson(s);
//发送消息
                            Message msg=Message.obtain();
                            msg.obj=newslist;
                            myHanlder.sendMessage(msg);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }.start();
        }else{
            Toast.makeText(this,"现在米有网,请稍后重试",Toast.LENGTH_SHORT).show();
            String s = jsonCacheDao.queryData(webUrl);
            List<ResultData.NewslistBean> newslistBeans = asyncJson(s);
            showData(newslistBeans);
        }
    }
    /**
     * 对json串进行解析
     * @param json
     * @return
     */
    public List<ResultData.NewslistBean> asyncJson(String json){
        Gson gson=new Gson();
        ResultData data=gson.fromJson(json,ResultData.class);
        List<ResultData.NewslistBean> newslist = data.getNewslist();
        return newslist;
    }
    private void showData(List<ResultData.NewslistBean> lists) {
        if (operType==1){
            dataAll.clear();
        }
        dataAll.addAll(lists);
        setLvAdapter();
        plv.onRefreshComplete();

    }

    private void setLvAdapter() {
        if (adapter==null){
            adapter=new MyAdapter(MainActivity.this,dataAll);
            plv.setAdapter(adapter);
        }else{
            adapter.notifyDataSetChanged();
        }
    }

    private void initPlv() {
        plv.setMode(PullToRefreshBase.Mode.BOTH);
        plv.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<ListView>() {
            @Override
            public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
                operType=1;
                pageIndex=1;
                webUrl="https://api.tianapi.com/wxnew/?key=48a7d7193e11bd2dd4a683b6e2f90a4f&num=10&page="+pageIndex;
                requestNetData();

            }

            @Override
            public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
                //上拉加载更多操作
                operType=2;
                pageIndex++;
                webUrl="https://api.tianapi.com/wxnew/?key=48a7d7193e11bd2dd4a683b6e2f90a4f&num=10&page="+pageIndex;
                requestNetData();

            }
        });
    }
    //将流转换成字符串
    public  String stremToString(InputStream stream){
        StringBuilder builder=new StringBuilder();

        try {
            BufferedReader reader=new BufferedReader(new InputStreamReader(stream));
            String str;
            while ((str=reader.readLine())!=null){
                builder.append(str);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return  builder.toString();
    }
}
MyAdaptrer适配器界面

import android.content.Context;
import android.graphics.Bitmap;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;

import java.util.List;

/**
 * Created by wang on 2018/4/1.
 */

public class MyAdapter extends BaseAdapter{
    private Context context;
    private List<ResultData.NewslistBean> datas;
    //第二步：显示图片配置
    private DisplayImageOptions options;

    public MyAdapter(Context context, List<ResultData.NewslistBean> datas) {
        this.context = context;
        this.datas = datas;

        options = new DisplayImageOptions.Builder()
                .cacheInMemory(true)//使用内存缓存
                .cacheOnDisk(true)//使用磁盘缓存
                .showImageOnLoading(R.mipmap.ic_launcher_round)//设置正在下载的图片
                .showImageForEmptyUri(R.mipmap.ic_launcher_round)//url为空或请求的资源不存在时
                .showImageOnFail(R.mipmap.ic_launcher_round)//下载失败时显示的图片
                .bitmapConfig(Bitmap.Config.RGB_565)//设置图片色彩模式
                .imageScaleType(ImageScaleType.EXACTLY)//设置图片的缩放模式
                .build();

    }

        @Override
    public int getCount() {
        return datas.size();
    }

    @Override
    public Object getItem(int position) {
        return datas.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView==null){
            convertView=View.inflate(context,R.layout.item,null);

        }
      TextView tv= convertView.findViewById(R.id.tv);
    ImageView img= convertView.findViewById(R.id.img);
    tv.setText(datas.get(position).getTitle());
        ImageLoader.getInstance().displayImage(datas.get(position).getPicUrl(),img,options);
        return convertView;
    }
}

myApplication辅助类
import android.app.Application;
import android.os.Environment;

import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

import java.io.File;

/**
 * Created by wang on 2018/4/1.
 */

public class MyApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        //程序的入口 函数

        //自定义缓存路径  sd卡下的piccache文件夹下
        File cachefile=new File(Environment.getExternalStorageDirectory().getPath()+"/piccache");
        //File cachefile1=getExternalCacheDir();//获取系统默认的sd卡缓存路径

        ImageLoaderConfiguration configuration=new ImageLoaderConfiguration.Builder(this)
                .memoryCacheExtraOptions(480, 800)//缓存图片最大的长和宽
                .threadPoolSize(2)//线程池的数量
                .threadPriority(4)
                .memoryCacheSize(2*1024*1024)//设置内存缓存区大小
                .diskCacheSize(20*1024*1024)//设置sd卡缓存区大小
                .diskCache(new UnlimitedDiscCache(cachefile))//自定义缓存目录
                .writeDebugLogs()//打印日志内容
                .diskCacheFileNameGenerator(new Md5FileNameGenerator())//给缓存的文件名进行md5加密处理
                .build();

        ImageLoader.getInstance().init(configuration);


    }


}
创建数据库
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * Created by wang on 2018/4/1.
 */

public class MyHelper extends SQLiteOpenHelper{

    public MyHelper(Context context) {
        super(context, "myapp", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
    db.execSQL("create table jsoncache(id integer primary key autoincrement,urlpath text,jsondata text)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

网络判断
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AlertDialog;

/**
 * Created by wang on 2018/4/1.
 */

public class NetStateUtil {

    /*
* 判断网络连接是否已开
* true 已打开  false 未打开
* */
    public static boolean isConn(Context context){
        boolean bisConnFlag=false;
        ConnectivityManager conManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo network = conManager.getActiveNetworkInfo();
        if(network!=null){
            bisConnFlag=network.isAvailable();
        }
        return bisConnFlag;
    }

    /**
     * 当判断当前手机没有网络时选择是否打开网络设置
     * @param context
     */
    public static void showNoNetWorkDlg(final Context context) {
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setIcon(R.mipmap.ic_launcher)         //
                .setTitle(R.string.app_name)            //
                .setMessage("当前无网络").setPositiveButton("设置", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                // 跳转到系统的网络设置界面
                Intent intent = null;
                // 先判断当前系统版本
                if(android.os.Build.VERSION.SDK_INT > 10){  // 3.0以上
                    intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);
                }else{
                    intent = new Intent();
                    intent.setClassName("com.android.settings", "com.android.settings.WirelessSettings");
                }
                context.startActivity(intent);

            }
        }).setNegativeButton("知道了", null).show();
    }
}


json串数据
public class ResultData {

    /**
     * code : 200
     * msg : success
     * newslist : [{"ctime":"2018-03-30","title":"2.0T+9AT的大7座SUV，卖多少钱能让你放弃汉兰达/奥迪Q5？","description":"车买买","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62898269.static/640","url":"https://mp.weixin.qq.com/s?__biz=MzA5NTU1MjEwNA==&idx=4&mid=2668673664&sn=197feccde9aad5f1c47772235c541e3e"},{"ctime":"2018-03-30","title":"黑人的头发养活了中国的一座城，这里藏着一段屈辱的民族史","description":"微在Wezeit","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62900480.jpg/640","url":"https://mp.weixin.qq.com/s?__biz=MzA5MjMzNTQyNw==&idx=1&mid=2656030884&sn=9a79b276f2c66c9b2694427d19ee5c72"},{"ctime":"2018-03-30","title":"朋友养了一只猛犬，网友本来是不相信的，直到靠近狗窝后.....","description":"大爱萌狗控","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62900520.jpg/640","url":"https://mp.weixin.qq.com/s?__biz=MjM5NjQ0MDE1OQ==&idx=2&mid=2650063440&sn=42593507b8b2f992795fb8ed6c675a5a"},{"ctime":"2018-03-30","title":"中国最美的20个旅行目的地，走过10个以上，就算超级旅行达人。","description":"带着相机去旅行","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62900363.jpg/640","url":"https://mp.weixin.qq.com/s?__biz=MzAxNjI1MzUwOA==&idx=3&mid=2247521649&sn=9c9c6d637348d975baa2c4352039f286"},{"ctime":"2018-03-30","title":"【入流】网红食物打造指南","description":"腾讯时尚","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-61887411.static/640","url":"https://mp.weixin.qq.com/s?__biz=MjM5MTIxOTEyMA==&idx=2&mid=2650591720&sn=e7e246e4bdf3c2659fd26f36b88697fa"},{"ctime":"2018-03-30","title":"深圳大学，我们不说再见...","description":"深圳全接触","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62811967.static/640","url":"https://mp.weixin.qq.com/s?__biz=MzI3MDAyMTUzOA==&idx=3&mid=2654766418&sn=b78ed1a957c065397506d10fb5fe1d8f"},{"ctime":"2018-03-30","title":"给女友打伞和给上级扶镜子是一样样儿的！","description":"丁香园","picUrl":"https://t1.qpic.cn/mblogpic/f01a972dbcc1060fd456/2000","url":"https://mp.weixin.qq.com/s?__biz=MTg0MzMwODA0MQ==&idx=2&mid=2653345924&sn=4e10623b69f593f82283d193ead0785e"},{"ctime":"2018-03-30","title":"这些车只卖10几万都是满分家用车 媳妇 丈母娘都爱你","description":"腾讯汽车","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-55422140.jpg/640","url":"https://mp.weixin.qq.com/s?__biz=MjM5NTAxMTg0MA==&idx=5&mid=2652994557&sn=a7d0d0e2774b77a5736e48ea8f879bb4"},{"ctime":"2018-03-30","title":"日裔球员晃断对手脚踝！随后的反应却爆发争议","description":"准者篮球训练营","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62351431.static/640","url":"https://mp.weixin.qq.com/s?__biz=MzA3MTQ4NjM3MQ==&idx=2&mid=2650627935&sn=0cae438f5695fcaea3c3da0f56bccae9"},{"ctime":"2018-03-30","title":"50岁中国辣妈西伯利亚-40℃拍照！外媒讥讽：纹身太显眼......","description":"带着相机去旅行","picUrl":"https://zxpic.gtimg.com/infonew/0/wechat_pics_-62809095.jpg/640","url":"https://mp.weixin.qq.com/s?__biz=MzAxNjI1MzUwOA==&idx=2&mid=2247521649&sn=e28e87c51627775b713974b51c3cc66b"}]
     */

    private int code;
    private String msg;
    private List<NewslistBean> newslist;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public List<NewslistBean> getNewslist() {
        return newslist;
    }

    public void setNewslist(List<NewslistBean> newslist) {
        this.newslist = newslist;
    }

    public static class NewslistBean {
        /**
         * ctime : 2018-03-30
         * title : 2.0T+9AT的大7座SUV，卖多少钱能让你放弃汉兰达/奥迪Q5？
         * description : 车买买
         * picUrl : https://zxpic.gtimg.com/infonew/0/wechat_pics_-62898269.static/640
         * url : https://mp.weixin.qq.com/s?__biz=MzA5NTU1MjEwNA==&idx=4&mid=2668673664&sn=197feccde9aad5f1c47772235c541e3e
         */

        private String ctime;
        private String title;
        private String description;
        private String picUrl;
        private String url;

        public String getCtime() {
            return ctime;
        }

        public void setCtime(String ctime) {
            this.ctime = ctime;
        }

        public String getTitle() {
            return title;
        }

        public void setTitle(String title) {
            this.title = title;
        }

        public String getDescription() {
            return description;
        }

        public void setDescription(String description) {
            this.description = description;
        }

        public String getPicUrl() {
            return picUrl;
        }

        public void setPicUrl(String picUrl) {
            this.picUrl = picUrl;
        }

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }
    }
}


数据表 插入 读取等
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

/**
 * Created by wang on 2018/4/1.
 */

public class JsonCacheDao {
    private MyHelper myHelper;
    private SQLiteDatabase database;

    public JsonCacheDao(Context context){
        myHelper=new MyHelper(context);
    }
    //添加方法
    public void insertData(String path,String json){
        database = myHelper.getWritableDatabase();
        database.delete("jsoncache","urlpath=?",new String[]{path});
        ContentValues values = new ContentValues();
    values.put("urlpath",path);
    values.put("jsondata",json);
    long rowid=database.insert("jsoncache",null,values);
        Log.d("zzz","插入的数据rowid:"+rowid);
    }
    public String queryData(String path){
        Log.d("zzz","正在查询数据");
     String data="";
        SQLiteDatabase database1 = myHelper.getWritableDatabase();
        Cursor cursor = database1.query("jsoncache", null, "urlpath=?", new String[]{path}, null, null, null);
        while(cursor.moveToNext()){
       data=cursor.getString(cursor.getColumnIndex("jsondata"));
    }
    return data;
    }
}

MianActivity的副本布局
<com.handmark.pulltorefresh.library.PullToRefreshListView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/plv"></com.handmark.pulltorefresh.library.PullToRefreshListView>

item布局
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:id="@+id/img"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv"
        android:layout_toRightOf="@id/img"/>

</RelativeLayout>

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