Get请求与Gson解析

MyActivity页面

package com.example.lx_two;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;

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.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private Button button;
    private ListView listView;
    private MyBase myBase;

    private final int UPDATE_UI = 1;
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case UPDATE_UI:
                    //将数据给adapter
                    myBase.setList((List<List<String>>) msg.obj);
                    break;
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取资源ID
        button = findViewById(R.id.but);
        listView = findViewById(R.id.listview);

//        list = new ArrayList<>();
        //设置适配器
        myBase = new MyBase(MainActivity.this);
        listView.setAdapter(myBase);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        initData();
                    }
                }).start();
            }
        });


    }

    private String urlstr = "https://suggest.taobao.com/sug?code=utf-8&q=%E6%89%8B%E6%9C%BA";

    private void initData(){
        try {
            URL url = new URL(urlstr);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setConnectTimeout(5000);
            urlConnection.setReadTimeout(5000);
            int responseCode = urlConnection.getResponseCode();
            if (responseCode == 200){
                String result = stream2String(urlConnection.getInputStream());
                Bean bean = new Gson().fromJson(result, Bean.class);
                handler.sendMessage(handler.obtainMessage(UPDATE_UI,bean.getResult()));

            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private String stream2String(InputStream inputStream) throws IOException {

        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        for (String tmp = bufferedReader.readLine(); tmp != null; tmp = bufferedReader.readLine()){
            stringBuilder.append(tmp);
        }

        return stringBuilder.toString();
    }
}

Bean页面

package com.example.lx_two;

import java.util.List;

public class Bean {

    private List<List<String>> result;

    public List<List<String>> getResult() {
        return result;
    }

    public void setResult(List<List<String>> result) {
        this.result = result;
    }
}

Adapter页面

package com.example.lx_two;

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 MyBase extends BaseAdapter {
    private List<List<String>> list;
    private Context context;

    public MyBase(Context context) {
        this.context = context;
        list = new ArrayList<>();
    }

    public void setList(List<List<String>> list) {
        this.list = list;
        notifyDataSetChanged();
    }

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

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

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

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

        return convertView;
    }

    class ViewHolder{
        private TextView textView;
    }
}

MainActivity的 布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/but"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:text="点击获取"
        />

    <ListView
        android:id="@+id/listview"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toBottomOf="@id/but"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        ></ListView>
</android.support.constraint.ConstraintLayout>

适配器的布局文件

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <TextView
        android:id="@+id/text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        />

</android.support.constraint.ConstraintLayout>