从URL创建JSON文件

Question

Hi guys I have a problem creating a JSON file from a google url that i have. This is my code that im using.

import android.util.Log;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;


public class DownloadUrl {

public String readUrl(String strUrl) throws IOException, InterruptedException {
    Log.d("URLS = ",strUrl);
    Thread.sleep(2000);
    String data = "";
    InputStream iStream = null;
    HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(strUrl);

        // Creating an http connection to communicate with url
        urlConnection = (HttpURLConnection) url.openConnection();

        // Connecting to url
        urlConnection.connect();

        // Reading data from url
        iStream = urlConnection.getInputStream();

        BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

        StringBuffer sb = new StringBuffer();

        String line = "";
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }

        data = sb.toString();
        Log.d("downloadUrl", data.toString());
        br.close();

    } catch (Exception e) {
        Log.d("Exception", e.toString());
    } finally {
        iStream.close();
        urlConnection.disconnect();
    }
    return data;
}

}

It works fine when i throw a url that looks like this into it. https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=40.7207523,-73.383851&radius=4828&type=bar&key=MYKEY

But when i try and throw a url that looks like this into it. https://maps.googleapis.com/maps/api/place/details/json?placeid=ChIJe3AmoGsr6IkRuWcK1LAh-DE&key=MYKEY

I get an error: D/GooglePlacesReadTask: java.lang.NullPointerException: Attempt to invoke virtual method 'void java.io.InputStream.close()' on a null object reference

I dont know how i fix this. Any help?

Answer 1

Aah you did not mention this is in android, I presume this because you said , android.os.NetworkOnMainThreadException in your comment

Android does not allow time consuming tasks on main thread, use AsyncTask to call your function or use plain old java thread

Answer 2

Network on main thread exception comes when you run a networking operation on main thread . Generally AsyncTask is used for these works but if you want to use the same code you written Just add..

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

StrictMode.setThreadPolicy(policy);