用AsyncHttpClient访问Json数据

访问的页面是：
北京天气

{"weatherinfo":{"city":"北京","cityid":"101010100","temp1":"15℃","temp2":"5℃","weather":"多云","img1":"d1.gif","img2":"n1.gif","ptime":"08:00"}}

使用JSONObject

用[]包裹的是JSONArray，这里的数据都是用{}包裹，所以都是JSONObject，里面还包括了一个key为weather的JSONObject

package com.jackie.jsontest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import net.callumtaylor.asynchttp.AsyncHttpClient;
import net.callumtaylor.asynchttp.response.StringResponseHandler;

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

public class MainActivity extends AppCompatActivity {
    private Button btnJO;
    private Button btnGS;
    private AsyncHttpClient asyncHttpClient = new AsyncHttpClient("http://www.weather.com.cn/adat/cityinfo/101010100.html");
    private String response;
    private String city;
    private String cityid;
    private String temp1;
    private String temp2;
    private String weather;
    private String img1;
    private String img2;
    private String ptime;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        asyncHttpClient.get(new StringResponseHandler() {
            @Override
            public void onSuccess() {
                response = getContent();
                Log.d("jackie", response);
                //返回的是：
                // {"weatherinfo":
                // {"city":"北京",
                // "cityid":"101010100",
                // "temp1":"15℃",
                // "temp2":"5℃",
                // "weather":"多云",
                // "img1":"d1.gif",
                // "img2":"n1.gif",
                // "ptime":"08:00"}
                // }
            }
        });
        btnJO = (Button) findViewById(R.id.btnJO);
        btnJO.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                parseJSONWithJSONObject(response);
            }

        });

    }

    private void parseJSONWithJSONObject(String response) {
        try {
            /*
            分析一下返回的json数据，均使用的是大括号包裹，说明是JSONObject
             */
            //得到第一层JSONObject
            JSONObject jsonObject = new JSONObject(response);
            //得到第二层JSONObject
            JSONObject weatherInfo = jsonObject.getJSONObject("weatherinfo");
            city = weatherInfo.getString("city");
            cityid = weatherInfo.getString("cityid");
            temp1 = weatherInfo.getString("temp1");
            temp2 = weatherInfo.getString("temp2");
            weather = weatherInfo.getString("weather");
            img1 = weatherInfo.getString("img1");
            img2 = weatherInfo.getString("img2");
            ptime = weatherInfo.getString("ptime");
            Log.d("jackie", "city: " + city);
            Log.d("jackie", "cityid: " + cityid);
            Log.d("jackie", "temp1: " + temp1);
            Log.d("jackie", "temp2: " + temp2);
            Log.d("jackie", "weather: " + weather);
            Log.d("jackie", "img1: " + img1);
            Log.d("jackie", "img2: " + img2);
            Log.d("jackie", "ptime: " + ptime);

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

    }
}

使用GSON解析

GSON解析实际上是将json数据映射成java实体类
例如这里的数据：

{"weatherinfo":{"city":"北京","cityid":"101010100","temp1":"15℃","temp2":"5℃","weather":"多云","img1":"d1.gif","img2":"n1.gif","ptime":"08:00"}}

第一个大括号代表着最外围的类，它有一个成员变量，就是weatherinfo:后面的大括号，所以这里我们需要两个类，分别代表最外面的大括号和里面的大括号

/**
 * 代表最外围的大括号的类
 * Created by Law on 2015/11/29.
 */
public class GSONObject {
    /*
      这里注意，变量的名字weatherinfo一定要和json数据中的一模一样，大小写要区分！
     */
    private WeatherInfo weatherinfo;


    public WeatherInfo getWeatherinfo() {
        return weatherinfo;
    }

    public void setWeatherinfo(WeatherInfo weatherinfo) {
        this.weatherinfo = weatherinfo;
    }
}

/**
 * 代表weatherinfo:{}
 * Created by Law on 2015/11/29.
 */
public class WeatherInfo {
    private String city;
    private String cityid;
    private String temp1;
    private String temp2;
    private String weather;
    private String img1;
    private String img2;
    private String ptime;

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public String getCityid() {
        return cityid;
    }

    public void setCityid(String cityid) {
        this.cityid = cityid;
    }

    public String getTemp1() {
        return temp1;
    }

    public void setTemp1(String temp1) {
        this.temp1 = temp1;
    }

    public String getTemp2() {
        return temp2;
    }

    public void setTemp2(String temp2) {
        this.temp2 = temp2;
    }

    public String getWeather() {
        return weather;
    }

    public void setWeather(String weather) {
        this.weather = weather;
    }

    public String getImg1() {
        return img1;
    }

    public void setImg1(String img1) {
        this.img1 = img1;
    }

    public String getImg2() {
        return img2;
    }

    public void setImg2(String img2) {
        this.img2 = img2;
    }

    public String getPtime() {
        return ptime;
    }

    public void setPtime(String ptime) {
        this.ptime = ptime;
    }

    @Override
    public String toString() {
        return "WeatherInfo{" +
                "city='" + city + '\'' +
                ", cityid='" + cityid + '\'' +
                ", temp1='" + temp1 + '\'' +
                ", temp2='" + temp2 + '\'' +
                ", weather='" + weather + '\'' +
                ", img1='" + img1 + '\'' +
                ", img2='" + img2 + '\'' +
                ", ptime='" + ptime + '\'' +
                '}';
    }
}

那么GSON解析就是这样的：

    private void parseJSONWithGSON(String response) {
        Gson gson = new Gson();
        GSONObject gsonObject = gson.fromJson(response, GSONObject.class);
        WeatherInfo weatherInfo = gsonObject.getWeatherinfo();
        Log.d("jackie", "city: " + weatherInfo.getCity());
        Log.d("jackie", "cityid: " + weatherInfo.getCityid());
        Log.d("jackie", "temp1: " + weatherInfo.getTemp1());
        Log.d("jackie", "temp2: " + weatherInfo.getTemp2());
        Log.d("jackie", "weather: " + weatherInfo.getWeather());
        Log.d("jackie", "img1: " + weatherInfo.getImg1());
        Log.d("jackie", "img2: " + weatherInfo.getImg2());
        Log.d("jackie", "ptime: " + weatherInfo.getPtime());

    }