これが私がやっていることです。
Android アプリに GetWeather クラスがあり、以下のようなオブジェクトをインスタンス化するときに現在の都市と州を渡すコンストラクターがあります。
GetWeather weather = new GetWeather(city_send,state_code);
次に、コンストラクターは、必要な都市、州、および API 資格情報を使用して API URL に ping を実行し、応答として気象データ json を受け取ります。json から特定の値を読み取ろうとしています。これは icon_url URL からコンテンツを取得して表示します。コードが現在立っているので、応答は正常に返されますが、json から icon_url の特定のデータを抽出しようとすると、logcat 警告が表示されます -org.json.JSONException: No value for icon_url
これが私のクラスのコードです-
package com.mypackage.android;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
public class GetWeather {
private static String WEATHER_URL = "http://api.wunderground.com/api/my_api_key/conditions/q/";
public String weather;
public String temperature_string;
public Bitmap weather_icon;
public GetWeather(String city, String state){
city = city.replaceAll(" ", "_");
//construct post URL
final String GET_WEATHER_URL = WEATHER_URL + state + "/" + city + ".json";
new Thread(new Runnable()
{
public void run()
{
String request = GET_WEATHER_URL;
HttpResponse rp = null;
JSONObject jObject = null;
try {
rp = (new DefaultHttpClient()).execute(new HttpPost(request));
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if (rp != null && rp.getStatusLine().getStatusCode() == HttpStatus.SC_OK){
Log.i("Get Weather", "Success");
HttpEntity entity = rp.getEntity();
InputStream is = null;
try {
is = entity.getContent();
} catch (IllegalStateException e2) {
e2.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
} catch (NullPointerException n1){
n1.printStackTrace();
}
final char[] buffer = new char[0x10000];
StringBuilder out = new StringBuilder();
Reader in = null;
String json_string_response = null;
try {
in = new InputStreamReader(is, "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (NullPointerException n1){
n1.printStackTrace();
}
int read = 0;
do {
try {
read = in.read(buffer, 0, buffer.length);
} catch (IOException e) {
e.printStackTrace();
} catch (NullPointerException n1){
n1.printStackTrace();
}
if (read>0) {
out.append(buffer, 0, read);
}
} while (read>=0);
try {
is.close();
json_string_response = out.toString();
} catch (IOException e1) {
e1.printStackTrace();
}
try {
jObject = new JSONObject(json_string_response);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
/*Here is where I try to get the data from the json for specific keys but it says no value found*/
weather = jObject.getString("weather");
temperature_string = jObject.getString("temperature_string");
String icon_url = jObject.getString("icon_url");
weather_icon = get_weather_icon(icon_url);
} catch (JSONException e4) {
// TODO Auto-generated catch block
e4.printStackTrace();
}
}else{
String response = rp.toString().toString();
Log.e("Get Weather", response);
}
}
}).start();
}
public static Bitmap get_weather_icon(String url){
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
bitmap = BitmapFactory.decodeStream((InputStream)new URL(url).getContent());
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
}
API呼び出しから抽出し、上記のコードに従って処理したjObjectの値は次のとおりです-（ニューヨーク、ニューヨークの天気データです）
{"response":{"features":{"conditions":1},"termsofService":"http:\/\/www.wunderground.com\/weather\/api\/d\/terms.html","version":"0.1"},"current_observation":{"precip_1hr_metric":" 0","wind_gust_mph":0,"precip_today_metric":"0","pressure_trend":"-","forecast_url":"http:\/\/www.wunderground.com\/US\/NY\/New_York.html","history_url":"http:\/\/www.wunderground.com\/weatherstation\/WXDailyHistory.asp?ID=KNYNEWYO64","estimated":{},"windchill_string":"42 F (6 C)","weather":"Scattered Clouds","station_id":"KNYNEWYO64","UV":"5","wind_gust_kph":0,"observation_epoch":"1364930056","precip_1hr_in":"-999.00","feelslike_string":"42 F (6 C)","observation_time":"Last Updated on April 2, 3:14 PM EDT","temp_f":46.2,"local_tz_long":"America\/New_York","relative_humidity":"29%","temp_c":7.9,"image":{"title":"Weather Underground","url":"http:\/\/icons-ak.wxug.com\/graphics\/wu2\/logo_130x80.png","link":"http:\/\/www.wunderground.com"},"solarradiation":"","visibility_mi":"10.0","observation_location":{"full":"Hells Kitchen, 48th St, NYC, New York, New York","elevation":"66 ft","state":"New York","longitude":"-73.989212","latitude":"40.762157","country_iso3166":"US","country":"US","city":"Hells Kitchen, 48th St, NYC, New York"},"heat_index_c":"NA","wind_mph":7.8,"precip_today_string":"0.00 in (0 mm)","feelslike_f":"42","observation_time_rfc822":"Tue, 02 Apr 2013 15:14:16 -0400","feelslike_c":"6","heat_index_f":"NA","heat_index_string":"NA","ob_url":"http:\/\/www.wunderground.com\/cgi-bin\/findweather\/getForecast?query=40.762157,-73.989212","dewpoint_string":"16 F (-9 C)","local_tz_offset":"-0400","wind_kph":12.6,"windchill_f":"42","windchill_c":"6","pressure_in":"29.96","wind_degrees":202,"dewpoint_c":-9,"pressure_mb":"1015","icon":"partlycloudy","local_time_rfc822":"Tue, 02 Apr 2013 15:24:21 -0400","precip_1hr_string":"-999.00 in ( 0 mm)","icon_url":"http:\/\/icons-ak.wxug.com\/i\/c\/k\/partlycloudy.gif","wind_dir":"SSW","dewpoint_f":16,"display_location":{"zip":"10001","full":"New York, NY","elevation":"17.00000000","state":"NY","longitude":"-73.99700928","latitude":"40.75013351","state_name":"New York","country_iso3166":"US","country":"US","city":"New York"},"visibility_km":"16.1","temperature_string":"46.2 F (7.9 C)","local_tz_short":"EDT","local_epoch":"1364930661","wind_string":"From the SSW at 7.8 MPH","precip_today_in":"0.00"}}
探している値が解析された応答にあることがわかるかもしれませんが、なぜそれを取得できないのか、または値が見つからないという警告が表示されるのはなぜですか? 私が間違っていること、またはjsonから以下の値を抽出するためにできることはありますか?
"weather":"Scattered Clouds"
"temperature_string":"46.2 F (7.9 C)"
"icon_url":"http://icons-ak.wxug.com/i/c/k/partlycloudy.gif"
ありがとう。