Antes de leer: utilicé librerías GSON descargables en este programa. http://webscripts.softpedia.com/script/Development-Scripts-js/Other-Libraries/Gson-71373.htmlAnálisis de cadenas JSON desde URL (servicio web RESTful) utilizando las bibliotecas GSON. Android
He estado tratando de analizar JSON desde hace bastante tiempo, pero cada vez que trato de obtener la cadena de la URL, el programa no "funciona". No falla ni se cierra ni recibe errores. Simplemente no hace el análisis. Mi programa está destinado a analizar desde http://api.geonames.org/weatherIcaoJSON?ICAO=LSZH&username=demo y tiene un botón para actualizar ejecutar el proceso de análisis de nuevo para que actualice la información. Si utilizo una cadena JSON codificada, el programa funciona perfectamente. Incluso coloco la cadena que se supone que se recupera de la URL; pero parece que no puedo obtenerlo directamente. Estoy usando las librerías GSON.
En el código, he proporcionado comentarios para explicar mi proceso de pensamiento. Tenga en cuenta que tengo 2 métodos diferentes que están tratando de usar la URL (pensé que tal vez la original estaba equivocada, así que traté de usar otra), esta era yo aferrándome a las pajas. Por favor, ayúdame. Gracias.
mi código:.
package com.android.testgson;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URI;
import java.net.URL;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.google.gson.Gson;
public class GSONTestActivity extends Activity {
/** Called when the activity is first created. */
//String test = "";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView tv = (TextView)findViewById(R.id.textViewInfo);
syncButtonClickListener();
runJSONParser(tv);
}
private void syncButtonClickListener()
{
Button syncButton = (Button)findViewById(R.id.buttonSync);
syncButton.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
TextView tv = (TextView)findViewById(R.id.textViewInfo);
runJSONParser(tv);
}
});
}
public InputStream getJSONData(String url){
// create DefaultHttpClient
HttpClient httpClient = new DefaultHttpClient();
URI uri; // for URL
InputStream data = null; // for URL's JSON
try {
uri = new URI(url);
HttpGet method = new HttpGet(uri); // Get URI
HttpResponse response = httpClient.execute(method); // Get response from method.
data = response.getEntity().getContent(); // Data = Content from the response URL.
} catch (Exception e) {
e.printStackTrace();
}
return data;
}
public void runJSONParser(TextView tv){
try{
Gson gson = new Gson();
//Reader r = new InputStreamReader(getJSONData("http://api.geonames.org/weatherIcaoJSON?ICAO=LSZH&username=demo"));
/**I tried parsing the URL, but it didn't work. No error messages, just didn't parse.*/
//Reader r = new InputStreamReader(getJSONData("android.resource://"+ getPackageName() + "/" + R.raw.yourparsable));
/**I tried parsing from local JSON file. Didn't work. Again no errors. The program simply stalls. */
//String testString = "{\"weatherObservation\":{\"clouds\":\"few clouds\",\"weatherCondition\":\"n/a\",\"observation\":\"LSZH 041320Z 24008KT 210V270 9999 FEW022 SCT030 BKN045 05/01 Q1024 NOSIG\",\"windDirection\":\"240\",\"ICAO\":\"LSZH\",\"elevation\":\"432\",\"countryCode\":\"CH\",\"lng\":\"8.516666666666667\",\"temperature\":\"5\",\"dewPoint\":\"1\",\"windSpeed\":\"08\",\"humidity\":\"75\",\"stationName\":\"Zurich-Kloten\",\"datetime\":\"2012-01-04 13:20:00\",\"lat\":\"47.46666666666667\",\"hectoPascAltimeter\":\"1024\"}}";
/**If I parse this string. The parser works. It is the same exact string like in the URL.*/
//String failString = "{\"status\":{\"message\":\"the hourly limit of 2000 credits demo has been exceeded. Please throttle your requests or use the commercial service.\",\"value\":19}}";
/**Even if the url delivers this string (because the hourly limit would be reached), the string is still parsed correctly.*/
String json = readUrl("http://api.geonames.org/weatherIcaoJSON?ICAO=LSZH&username=demo");
/**At this point I tried a different means of accessing the URL but still I had the exact same problem*/
Observation obs = gson.fromJson(json, Observation.class);
// "json" can be replaced with r, testString, failString to see all my previous results.
if (obs.getWeatherObservation()!=null)
{
tv.setText("Clouds - " + obs.getWeatherObservation().getClouds()
+ "\nTemperature - " + obs.getWeatherObservation().getTemperature()
+ "\nWind Speed - " + obs.getWeatherObservation().getWindSpeed()
+ "\nHumidity - " + obs.getWeatherObservation().getHumidity());
}
else if (obs.getStatus()!=null)
{
tv.setText("Message - " + obs.getStatus().getMessage()
+ "\nValue - " + obs.getStatus().getValue());
}
}catch(Exception ex){
ex.printStackTrace();
}
}
public static String readUrl(String urlString) throws Exception {
BufferedReader reader = null;
try{
URL url = new URL(urlString);
reader = new BufferedReader(new InputStreamReader (url.openStream()));
StringBuffer buffer = new StringBuffer();
int read;
char[]chars = new char[1024];
while ((read = reader.read(chars)) != -1)
buffer.append(chars, 0, read);
return buffer.toString();
} finally {
if (reader != null)
reader.close();
}
}
}
Podría publicar su 'Observation.java'? – curioustechizen
¿Ha verificado que 'readURL' de hecho está devolviendo la cadena que espera? –