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Start your free trialEmerson Gonzalez
Front End Web Development Techdegree Student 22,500 PointsNo Items to display
When I run my App it only shows: No items to display! I'd greatly appreciate any help you can provide!
package com.emersonleaf.blogreader;
import android.app.ListActivity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Html;
import android.util.Log;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MainListActivity extends ListActivity {
protected String[] mBlogPostTitles;
public static final int NUMBER_OF_POSTS = 20;
public static final String TAG = MainListActivity.class.getSimpleName();
protected JSONObject mBlogData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_list);
if (isNetworkAvailable()) {
GetBlogPostTask getBlogPostTask = new GetBlogPostTask();
getBlogPostTask.execute();
} else {
Toast.makeText(this, "Network is unavailable!", Toast.LENGTH_LONG).show();
}
// Resources resources = getResources();
//mBlogPostTiles = resources.getStringArray(R.array.android_names);
//ArrayAdapter <String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, mBlogPostTiles);
//setListAdapter(adapter);
//Toast.makeText(this, getString(R.string.no_items),Toast.LENGTH_LONG).show();
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()) {
isAvailable = true;
}
return isAvailable;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_list, menu);
return true;
}
public void updateList() {
if (mBlogData == null) {
//to do: handle error
} else {
try {
JSONArray jsonPosts = mBlogData.getJSONArray("posts");
mBlogPostTitles = new String[jsonPosts.length()];
for (int i = 0; i < jsonPosts.length(); i++){
JSONObject post = jsonPosts.getJSONObject(i);
String title = post.getString("title");
title = Html.fromHtml(title).toString();
mBlogPostTitles[i] = title;
}
ArrayAdapter <String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, mBlogPostTitles);
setListAdapter(adapter);
} catch (JSONException e) {
Log.e(TAG, "Exception caught!", e);
}
}
}
private class GetBlogPostTask extends AsyncTask<Object, Void, JSONObject> {
@Override
protected JSONObject doInBackground(Object[] objects) {
int responseCode = -1;
JSONObject jsonResponse = null;
//URL blogFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count =" + NUMBER_OF_POSTS);
try {
URL blogFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count=" + NUMBER_OF_POSTS);
HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
connection.connect();
//Creating are response code so that we can get data from the internet
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = connection.getInputStream();
Reader reader = new InputStreamReader(inputStream);
int nextCharacter; // read() returns an int, we cast it to char later
String responseData = "";
while (true) { // Infinite loop, can only be stopped by a "break" statement
nextCharacter = reader.read(); // read() without parameters returns one character
if (nextCharacter == -1) // A return value of -1 means that we reached the end
break;
responseData += (char) nextCharacter; // The += operator appends the character to the end of the string
jsonResponse = new JSONObject(responseData);
}
} else {
Log.i(TAG, "Unsuccessful HTTP response Code: " + responseCode);
}
} catch (MalformedURLException e) {
Log.e(TAG, "Exception caught: ", e);
} catch (IOException e) {
Log.e(TAG, "Exception caught: ", e);
} catch (Exception e) {
Log.e(TAG, "Exception caught: ", e);
}
return jsonResponse;
}
@Override
protected void onPostExecute(JSONObject result) {
mBlogData = result;
updateList();
}
}
}
Ryan Farber
5,329 PointsFrom the look of it, you haven't finished the whole BlogReader. It should sort itself out when you finish the application
Harry James
14,780 PointsHey Emerson - Are you getting any errors in LogCat? If so, can you provide them?
Sultan Aljaradi
2,592 PointsSultan Aljaradi
2,592 Pointssame problem wit me
i use android studio
help me