CODEWITHSUNDEEP
androidhttprequestnoclassdeffounderror
Gilbert Samaha
Gilbert Samaha

Reputation: 11

HTTP request via Android Studio NoClassDefFoundError

I am building an app on Android Studio in which I have to keep the currency rates synchronized with an external source through a JSON object. I have followed this tutorialwhich was given to me by another answer on this forum. The source seems reliable. However, I keep getting a NoClassDefError. I have put a flag marked as //Exception in my code to show you where the exception occurs. Note that i have added httpclient-4.3-beta1.jar as a library so I don't think it's a dependency problem. I have found topics about the same issue but they only provide explanations and no answers. This is my code. Any help would be much appreciated! Thank you.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.http.HttpEntity;
import org.apache.http.ParseException;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;

public class LiveResponseDemo{

    // essential URL structure is built using constants
    public static final String ACCESS_KEY = "YOUR_ACCESS_KEY";
    public static final String BASE_URL = "https://apilayer.net/api/";
    public static final String ENDPOINT = "live";

    // this object is used for executing requests to the (REST) API
    //Exception
    static CloseableHttpClient httpClient = HttpClients.createDefault(); 


    public static void sendLiveRequest(){

        // The following line initializes the HttpGet Object with the URL in order to send a request
        HttpGet get = new HttpGet(BASE_URL + ENDPOINT + "?access_key=" + ACCESS_KEY);

        try {
            CloseableHttpResponse response =  httpClient.execute(get);
            HttpEntity entity = response.getEntity();

            // the following line converts the JSON Response to an equivalent Java Object
            JSONObject exchangeRates = new JSONObject(EntityUtils.toString(entity));

            System.out.println("Live Currency Exchange Rates");

            // Parsed JSON Objects are accessed according to the JSON resonse's hierarchy, output strings are built
            Date timeStampDate = new Date((long)(exchangeRates.getLong("timestamp")*1000));
            DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss a");
            String formattedDate = dateFormat.format(timeStampDate);
            System.out.println("1 " + exchangeRates.getString("base") + " in GBP : " + exchangeRates.getJSONObject("rates").getDouble("GBP") + " (as of " + formattedDate + ")");
            System.out.println("\n");
            response.close();

        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

Upvotes: 0

Views: 2255

Answers (1)

Rene M.
Rene M.

Reputation: 2690

It's not the correct answer on his question, but the solution that worked for him.

  1. HttpClient is not part of the Android SDK anymore and is marked as deprecated.
  2. Using a library jar with an httpclient impl. brings up the httpclient framework twice in the classpath, which makes it hard.

The solution I suggested is to keep on the standard and follow the advice from google. As described in the API docs: http://developer.android.com/reference/org/apache/http/client/HttpClient.html

We should use URLConnection as replacement for apache httpclient. As described here: http://developer.android.com/reference/java/net/URLConnection.html

Upvotes: 2

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