Http请求和Json解析结合实例

Http请求和Json解析结合实例—-天气预报项目

首先创建一个WeatherActivity，修改布局文件，添加控件，设置id

xml文件  activity_weather

<LinearLayout 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"
    android:orientation="vertical"
    tools:context="com.example.administrator.urlapplication.WeatherActivity">

    <EditText
        android:id="@+id/city_et"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:hint="请输入城市名"/>

    <Button
        android:id="@+id/search_btn"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:text="查询"/>

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:id="@+id/weather_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="天气:"
            android:textSize="30sp"/>
        <TextView
            android:id="@+id/temp_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="温度:"
            android:textSize="30sp"/>
        <TextView
            android:id="@+id/wind_tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="风力："
            android:textSize="30sp"/>
    LinearLayout>
LinearLayout>

接着 在WeatherActivity内绑定id，设置监听，启动线程，并使用Http请求和Json解析结合

package com.example.administrator.urlapplication;

import android.content.Context;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

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;

public class WeatherActivity extends AppCompatActivity {
    private TextView weatherTV;
    private TextView windTV;
    private TextView tempTV;
    private TextView searchBtn;
    private TextView cityET;

    //网络获取，和风天气
    private String weatherAPI="https://free-api.heweather.com/s6/weather-now?key=f4df0dc926f54557b9c94b6c09451b51&location=";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_weather);

        bindID();

        searchBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String city=cityET.getText().toString();
                new MyTask().execute(weatherAPI+city);
            }
        });
    }

    class MyTask extends AsyncTask{


        @Override
        protected String doInBackground(String... strings) {
            StringBuffer stringBuffer=new StringBuffer();
            try {
                //创建URL对象，接收api
                URL url=new URL(strings[0]);
                HttpURLConnection connection= (HttpURLConnection) url.openConnection();
                InputStream inputStream=null;
                //判断是否联网
                if (connection.getResponseCode()==200){
                    inputStream=connection.getInputStream();//只有网络正常且返回数据正常时，才能创建数据流；
                }else {
                    return "network_failed";
                }

                InputStreamReader reader=new InputStreamReader(inputStream);
                BufferedReader bufferedReader=new BufferedReader(reader);

                String temp="";

                while ((temp=bufferedReader.readLine())!=null){
                    stringBuffer.append(temp);
                }

                bufferedReader.close();
                reader.close();
                inputStream.close();

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }

            return stringBuffer.toString();
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);

            if (s.equals("network_failed")){
                Toast.makeText(WeatherActivity.this,"网络连接失败",Toast.LENGTH_SHORT).show();
            }else {
                //JSON解析

                try {
                    //创建jsonobject对象，接收字符串
                    JSONObject object=new JSONObject(s);
                    //创建jsonarray对象，接收数组
                    JSONArray array=object.getJSONArray("HeWeather6");
                    //创建jsonobject对象，接收数组第一个对象
                    JSONObject object1=array.getJSONObject(0);
                    //创建jsonobject对象，接收对象
                    JSONObject nowObj=object1.getJSONObject("now");
                    //读取数据
                    String weather=nowObj.getString("cond_txt");
                    String wind=nowObj.getString("wind_dir")+nowObj.getString("wind_sc")+"级";
                    String temperature=nowObj.getString("tmp");

                    weatherTV.setText(weather);
                    windTV.setText(wind);
                    tempTV.setText(temperature);

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

            }
        }
    }
    private void bindID(){
        cityET=findViewById(R.id.city_et);
        searchBtn=findViewById(R.id.search_btn);
        windTV=findViewById(R.id.wind_tv);
        tempTV=findViewById(R.id.temp_tv);
        weatherTV=findViewById(R.id.weather_tv);
    }
}

图片展示