调用天气预报api

    进入和风天气网主页   http://heweather.com/  ，查看API文档可发现我们需要的天气预报指数数据挺全面的，下面以获取当天的最高温度，最低温度，当前温度，PM2.5,空气质量，紫外线强度，湿度为例：

   布局界面比较简单，一个按钮和显示文本，点击按钮获取天气指数在文本框里显示

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/LinearLayout1"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <Button

        android:id="@+id/btn"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="获取天气情况" />

    <TextView

        android:id="@+id/txt"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="天气数据：" />

</LinearLayout>

以北京的天气为例：

package com.example.dfd;

import java.io.BufferedReader;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.URL;

import android.app.Activity;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.TextView;

public class MainActivity extends Activity {

    TextView txtTextView;

    Button btn;

    String result = “; 

    String target="https://api.heweather.com/x3/weather?cityid=CN101010100&key=af71e684a8f540feaaad7c92566324c1";

    URL url;

    Handler handler;

   WeatherContent content;   

   @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

         btn = (Button)findViewById(R.id.btn);

         txtTextView = (TextView)findViewById(R.id.txt);

         content = new WeatherContent();      

         btn.setOnClickListener(new OnClickListener() {

            

            @Override

            public void onClick(View v) {

                new Thread(new Runnable() {

                    

                    @Override

                    public void run() {

                        send();

                        Message message = handler.obtainMessage();

                        handler.sendMessage(message);

                    }

                }).start();

            }

        });

         handler = new Handler(){

            @Override

            public void handleMessage(Message msg) {

                super.handleMessage(msg);

                if(result!=null){

                    txtTextView.setText(jiexi());

                }

            }

        };

    }

    public void send(){

        try {

            url = new URL(target);

            HttpURLConnection connection = (HttpURLConnection)url.openConnection();

            InputStream is = connection.getInputStream();

            BufferedReader buffered = new BufferedReader(new InputStreamReader(is, "UTF-8"));

            String input = null;

            while ((input = buffered.readLine())!=null) {

               result+=input+"\n";

            }

            buffered.close();

            connection.disconnect();

            

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

 private String jiexi() {

        try {

            JSONArray jsonObjs = new JSONObject(result).getJSONArray("HeWeather data service 3.0");

            JSONObject japi = ((JSONObject) jsonObjs.opt(0))

                    .getJSONObject("aqi");

            JSONObject japi_city = japi.getJSONObject("city");

            //PM2.5          

           String pm25 = japi_city.getString("pm25");

            // 空气质量

            String qlty = japi_city.getString("qlty");

            JSONObject jbasic = ((JSONObject) jsonObjs.opt(0))

                    .getJSONObject("basic");

             //城市名称

             String city = jbasic.getString("city");

            JSONArray jdaily_forecast = ((JSONObject) jsonObjs.opt(0))

                    .getJSONArray("daily_forecast");

            JSONObject jdaily_forecast_1 = ((JSONObject) jdaily_forecast.opt(0))

                    .getJSONObject("tmp");

            // 最高温度

            String max = jdaily_forecast_1.getString("max");

            String min = jdaily_forecast_1.getString("min");

            JSONObject jnow = ((JSONObject) jsonObjs.opt(0))

                    .getJSONObject("now");

            //当前温度

            String tmp = jnow.getString("tmp");

            // 湿度

            String hum = jnow.getString("hum");

           //天气描述

            String txtdescrible = jnow.getJSONObject("cond").getString("txt");

            content.setTxtdescrible(txtdescrible);

            JSONObject jsuggestion = ((JSONObject) jsonObjs.opt(0))

                    .getJSONObject("suggestion");

           //紫外线

           String ultraviolet = jsuggestion.getJSONObject("uv").getString("brf");

            return "城市：" + city +" ，PM2.5:" + pm25 + "，空气质量：" + qlty + " ，当前温度：" + tmp + "，湿度：" + hum

                    + "，天气情况：" + txtdescrible

                    + "，紫外线：" + ultraviolet + "，温度：" + min + "℃~" + max +
"℃";

        } catch (JSONException ex) {

          ex.printStackTrace();      

    }

        return null;

    }