android JSON解析資料-解析天氣預報

#概要
筆者近期做到對天氣預報JSON資料解析，在此小記。
天氣預報介面：http://wthrcdn.etouch.cn/weather_mini?citykey=101200101
JSON資料如下：

{
    "desc": "OK",
    "status": 1000,
    "data": {
        "wendu": "14",
        "ganmao": "天氣轉涼，空氣溼度較大，較易發生感冒，體質較弱的朋友請注意適當防護。",
        "forecast": [
            {
                "fengxiang": "無持續風向",
                "fengli": "微風級",
                "high": "高溫 17℃",
                "type": "小雨",
                "low": "低溫 10℃",
                "date": "30日星期四"
            },
            {
                "fengxiang": "無持續風向",
                "fengli": "微風級",
                "high": "高溫 18℃",
                "type": "多雲",
                "low": "低溫 7℃",
                "date": "31日星期五"
            },
            {
                "fengxiang": "無持續風向",
                "fengli": "微風級",
                "high": "高溫 20℃",
                "type": "晴",
                "low": "低溫 8℃",
                "date": "1日星期六"
            },
            {
                "fengxiang": "無持續風向",
                "fengli": "微風級",
                "high": "高溫 23℃",
                "type": "晴",
                "low": "低溫 10℃",
                "date": "2日星期天"
            },
            {
                "fengxiang": "無持續風向",
                "fengli": "微風級",
                "high": "高溫 23℃",
                "type": "多雲",
                "low": "低溫 12℃",
                "date": "3日星期一"
            }
        ],
        "yesterday": {
            "fl": "微風",
            "fx": "無持續風向",
            "high": "高溫 21℃",
            "type": "陰",
            "low": "低溫 12℃",
            "date": "29日星期三"
        },
        "aqi": "114",
        "city": "武漢"
    }
}

最終解析效果：

#解析概述
1、首先，接到的整個資料可以轉化為JSONObject物件。
2、通過整個資料的JSONObject物件獲取到data中的資料，也是一個JSONObject物件。在data中就可以獲取到此時溫度，以及城市等資訊。
3、通過data的JSONObject物件可以獲取到forecast中的資料，forecast中的資料則是一個JSONArray物件。
4、通過forecast的JSONArray物件可以獲取到近幾天的天氣資訊，每一條為一個JSONObject物件。

#程式碼
方便起見，筆者使用了volley框架，讀者新建專案需要在build.gradle的dependencies中新增如下:

compile 'eu.the4thfloor.volley:com.android.volley:2015.05.28'

MainActivity.java:

package com.example.double2.jsontext;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.TextView;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class MainActivity extends AppCompatActivity {

    private TextView tvMain;
    private RequestQueue mRequestQueue;

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

        initView();
    }

    private void initView() {
        tvMain = (TextView) findViewById(R.id.tv_main);
        mRequestQueue = Volley.newRequestQueue(this);

        JsonObjectRequest mJsonObjectRequest = new JsonObjectRequest(
                "http://wthrcdn.etouch.cn/weather_mini?citykey=101200101",
                null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            JSONObject data = new JSONObject(response.getString("data"));
                            JSONArray forecast = data.getJSONArray("forecast");
                            JSONObject todayWeather = forecast.getJSONObject(0);

                            String wendu = data.getString("wendu") + "\n";
                            String ganmao = data.getString("ganmao") + "\n";
                            String high = todayWeather.getString("high") + "\n";
                            String low = todayWeather.getString("low") + "\n";
                            String date = todayWeather.getString("date") + "\n";
                            String city = data.getString("city") + "\n";

                            tvMain.setText(wendu + ganmao + high + low + date+city);
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("TAG", error.getMessage(), error);
            }
        });

        mRequestQueue.add(mJsonObjectRequest);
    }

}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="10dp"
    >

    <TextView
        android:id="@+id/tv_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        />

</LinearLayout>