我的应用程序无法从服务器读取数据，但我在代码或错误日志中找不到错误。事实上，在检查我的API后，链接工作正常。 INTERNET和WRITE_EXTERNAL_STORAGE权限已在清单中设置。
我的代码：
package com.berthojoris.bacaberita;
import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.berthojoris.bacaberita.adapter.BeritaAdapter;
import com.berthojoris.bacaberita.bean.BeritaBean;
import com.berthojoris.bacaberita.lib.Constants;
import com.berthojoris.bacaberita.lib.ImageLoader;
import com.berthojoris.bacaberita.lib.JSONParser;
import com.berthojoris.bacaberita.lib.Utils;
import com.berthojoris.bacaberita.sqlite.UtilBerita;
public class Berita extends ListActivity {
ProgressDialog dialog;
private static String urlBerita = "http://newapi.bacaberita.com/berita";
public ImageLoader imageLoader;
private JSONParser jParser;
Toast msg;
TextView notfound;
JSONArray contacts = null;
ArrayList<BeritaBean> AmbilDataBean = new ArrayList<BeritaBean>();
BeritaAdapter adapter;
UtilBerita UtilBerita;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dialog = new ProgressDialog(this);
UtilBerita = new UtilBerita(this);
imageLoader = new ImageLoader(this.getApplicationContext());
notfound = (TextView) findViewById(R.id.notfound);
notfound.setVisibility(View.GONE);
getListView().setVisibility(View.VISIBLE);
AmbilDataBean = new ArrayList<BeritaBean>();
adapter = new BeritaAdapter(this, AmbilDataBean);
setListAdapter(adapter);
Utils.setPolicyThread();
// Creating JSON Parser Instance
jParser = new JSONParser();
Log.e("Berita Activity", "TOTAL SIZE DATABASE : "
+ UtilBerita.ReadBerita().size());
if (UtilBerita.ReadBerita().size() < 1) {
Log.e("Berita Activity", "DATABASE KOSONG. JALANKAN ASYNC");
new async().execute();
} else {
AmbilDataBean = UtilBerita.ReadBerita();
adapter.setItem(AmbilDataBean);
Log.e("Berita Activity", "DATABASE DIAMBIL");
}
setTimerRefresh();
}// Tutup onCreate
private class async extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
AmbilDataBean = new ArrayList<BeritaBean>();
dialog.setMessage("Please wait...");
dialog.setCanceledOnTouchOutside(false);
dialog.show();
}
@Override
protected String doInBackground(Void... params) {
String jsonContent = jParser.getJSONDataFromUrl(urlBerita);
Log.e("Berita Activity", "PROSES BACKGROUND DIJALANKAN");
return jsonContent;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (result.length() > 0) {
dialog.dismiss();
// parsing disini
JSONObject json = null;
try {
json = new JSONObject(result);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(Constants.TAG_ITEM);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(Constants.TAG_MenuID);
String judul = c.getString(Constants.TAG_Title);
//String img = c.getString(Constants.TAG_Link);
String desk = c.getString(Constants.TAG_Post);
String date = c.getString(Constants.TAG_Created);
BeritaBean mb = new BeritaBean();
mb.setID(id);
mb.setTitle(judul);
//mb.setLink("http://" + img);
mb.setPost(desk);
mb.setCreated(date);
AmbilDataBean.add(mb);
}
adapter.setItem(AmbilDataBean);
Log.e("Berita Activity",
"PROSES SELESAI. DATA AKAN DITAMPILKAN");
} catch (Exception e) {
dialog.dismiss();
Toast.makeText(getBaseContext(),
"Connection Error. Please try again...",
Toast.LENGTH_SHORT).show();
}
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,
View view, int position, long id) {
}
});
} catch (Exception e) {
dialog.dismiss();
Toast.makeText(getBaseContext(),
"Connection Error. Please try again...",
Toast.LENGTH_SHORT).show();
}
} // Tutup if (result.length() > 0)
else {
dialog.dismiss();
Toast.makeText(getBaseContext(),
"Data Not Found. Please try again...",
Toast.LENGTH_SHORT).show();
}
if (AmbilDataBean.size() < 1) {
notfound.setVisibility(View.VISIBLE);
getListView().setVisibility(View.GONE);
} else {
for (BeritaBean bean : AmbilDataBean) {
if (UtilBerita.getDetailWhereID(bean.getID()).getID() == null) {
Log.e("Berita Activity",
"Insert database : " + bean.getID());
UtilBerita.CreateData(bean);
} else {
Log.e("Berita Activity",
"Update database : " + bean.getID());
UtilBerita.UpdateBerita(bean);
}
}
notfound.setVisibility(View.GONE);
getListView().setVisibility(View.VISIBLE);
}
} // Tutup onPostExecute
} // Tutup private class async extends AsyncTask
// =========================================================================================================================
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
new AlertDialog.Builder(this)
.setIcon(android.R.drawable.ic_dialog_alert)
.setMessage(R.string.really_quit)
.setPositiveButton(R.string.yes,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
finish();
}
}).setNegativeButton(R.string.no, null).show();
return true;
} else {
return super.onKeyDown(keyCode, event);
}
}
// =========================================================================================================================
// Declare the timer
Timer timer = null;
final Handler handler = new Handler();
public void setTimerRefresh() {
timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
Log.e("Main Activity", "RUNNING TASK...");
new async().execute();
}
});
}
}, 1000 * 60 * 1, 1000 * 25);
}
@Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
@Override
protected void onDestroy() {
super.onDestroy();
if (timer != null) {
timer.cancel();
timer = null;
}
if (UtilBerita != null)
UtilBerita.Close();
}
}
==更新==
我的常数类：
package com.berthojoris.bacaberita.lib;
public class Constants {
public static final String TAG_ITEM = "items";
public static final String TAG_MenuID = "Menu_ID";
public static final String TAG_IsDisplay = "IsDisplay";
public static final String TAG_CategoryName = "CategoryName";
public static final String TAG_CategoryID = "Category_ID";
public static final String TAG_ContentID = "Content_ID";
public static final String TAG_Title = "Title";
public static final String TAG_Post = "Post";
public static final String TAG_Link = "Link";
public static final String TAG_Meta = "Meta";
public static final String TAG_CreatedBy = "CreatedBy";
public static final String TAG_Created = "Created";
public static final String TAG_StartDisplay = "StartDisplay";
public static final String TAG_Counter = "counter";
}
答案 0 :(得分：0)
您必须从jsonObject items检索jsonArray。但是在您的代码中，您没有在任何地方使用items。试试这个：
String jsonStr = new ConnectionService().connectionGet("http://newapi.bacaberita.com/berita","");
JSONObject jsonObject = new JSONObject(jsonStr);
System.out.println("..........JSON OBJECT.............");
System.out.println(jsonObject); // full json Object
JSONArray jsonArray = jsonObject.getJSONArray("items");
System.out.println("..........JSON ARRAY PARSING.............");
for(int i=0;i<jsonArray.length();i++)
{
String menu_id = jsonArray.getJSONObject(i).getString("Menu_ID");
String is_display = jsonArray.getJSONObject(i).getString("IsDisplay");
System.out.println("MENU_ID: "+menu_id);
System.out.println("IsDisplay: "+is_display);
}
以上示例中使用的方法如下：
public static String connectionGet(String url, String parameter) throws MalformedURLException, ProtocolException, IOException {
URL url1 = new URL(url);
HttpURLConnection request1 = (HttpURLConnection) url1.openConnection();
request1.setRequestMethod("GET");
request1.connect();
String responseBody = convertStreamToString(request1.getInputStream());
return responseBody;
}
private static String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line).append("\n");
}
} catch (IOException e) {
} finally {
try {
is.close();
} catch (IOException e) {
}
}
return sb.toString();
}