//1主 mainactivity介面

package com.example.guoxinyu20181101;
import android.annotation.SuppressLint;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.UrlQuerySanitizer;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;


import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Collections;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private Button button;
    private ConnectionBase mBase;
    private final int UPDATE_UI = 1;
    @SuppressLint("HandlerLeak")
    private Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case UPDATE_UI:
                    // List<ConnectionBean.Result> lists = (List<ConnectionBean.Result>) msg.obj;
                    List<List<String>> lists = (List<List<String>>) msg.obj;
                    mBase.setmlists(lists);
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //獲取資源id
        listView = findViewById(R.id.lv_list);
        button = findViewById(R.id.btn);
        mBase = new ConnectionBase(MainActivity.this);
        listView.setAdapter(mBase);
        //點選載入資料
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //判斷網路是否可用
                if (!NetUtil.hasNetWork(MainActivity.this)) {
                    showNotNetWork();
                    return;
                }
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        requestConnection();

                    }
                }).start();
            }
        });
        //點選監聽
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                List<String> data = mBase.getItem(position);
                Toast.makeText(MainActivity.this, data.get(0) + ":" + data.get(1), Toast.LENGTH_SHORT).show();
            }
        });

    }

    //彈框提示網路的方法
    private void showNotNetWork() {
        new AlertDialog.Builder(MainActivity.this)
                .setTitle("無網路")
                .setMessage("當前網路不可用，是否去設定？")
                .setPositiveButton("確認", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                        Intent intent = new Intent("android.settings.WIRELESS_SETTINGS");
                        startActivity(intent);
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                })
                .show();
    }

    //載入資料的方法
    private String urlStr = "https://suggest.taobao.com/sug?code=utf-8&q=%E6%89%8B%E6%9C%BA";

    public void requestConnection() {
        try {
            //定義url地址
            URL url = new URL(urlStr);
            //開啟連線
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            //設定請求方式
            urlConnection.setRequestMethod("GET");
            //設定超時
            urlConnection.setReadTimeout(5000);
            urlConnection.setConnectTimeout(5000);
            //獲取請求碼
            int responseCode = urlConnection.getResponseCode();
            if (responseCode == 200) {
                String json = stream2String(urlConnection.getInputStream());
                //得到gson
                Gson gson = new Gson();
                ConnectionBean connectionBean = gson.fromJson(json, ConnectionBean.class);
                handler.sendMessage(handler.obtainMessage(UPDATE_UI, connectionBean.getResult()));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
	//位元組流轉換為字元流
    public String stream2String(InputStream is) throws IOException {
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        StringBuilder builder = new StringBuilder();
        for (String tem = br.readLine(); tem != null; tem = br.readLine()) {
            builder.append(tem);
        }
        return builder.toString();
    }
}

 

//介面卡介面

package com.example.guoxinyu20181101;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class ConnectionBase extends BaseAdapter {
    private List<List<String>> lists;
    private Context mContext;

    public ConnectionBase(Context mContext) {
        this.mContext = mContext;
        //初始化
        lists = new ArrayList<>();
    }

    public void setmlists(List<List<String>> lists) {
        this.lists = lists;
        notifyDataSetChanged();
    }

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

    @Override
    public List<String> getItem(int position) {
        return lists.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.listitem, parent, false);
            holder = new ViewHolder();
            holder.text = convertView.findViewById(R.id.text);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.text.setText(getItem(position).get(0));
        return convertView;
    }

    class ViewHolder {
        private TextView text;
    }
}

 

//判斷是否有網路的類

package com.example.guoxinyu20181101;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class NetUtil {
    //判斷是否有網路
    public static boolean hasNetWork(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
        return activeNetworkInfo!=null && activeNetworkInfo.isAvailable();
    }
}

 

//存放資料的BEAN類

package com.example.guoxinyu20181101;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class NetUtil {
    //判斷是否有網路
    public static boolean hasNetWork(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
        return activeNetworkInfo!=null && activeNetworkInfo.isAvailable();
    }
}

//配置檔案

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.guoxinyu20181101">
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
                <!--跳轉到網路設定的許可權-->
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
            </intent-filter>
        </activity>
    </application>

</manifest>