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因此，我有一个线程正在幕后为应用程序处理一些网络资源，但由于某种原因，IDE一直在想我正在更新UI，不要停止崩溃。我将其更改为一个AsyncTask，现在我得到一个索引超出范围错误。在开始使用线程之前，应用程序工作正常，但实际上很慢。我没有改变我刚刚添加到线程中的任何原始代码。所以我知道我的原始代码不是问题，它是创建AsyncTask的代码，或者至少应该是代码。我的代码与错误一起如下图所示：添加AsyncTask后指数超出范围错误
主要的Java文件
package shc_BalloonSat.namespace;
import java.text.DecimalFormat;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.net.ConnectivityManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.TextView;
import android.widget.Toast;
public class Shc_BalloonSat_Activity extends Activity
{
int historyCountFromUser;
httpAPI api;
mapAPI map;
runDialog dialog;
DecimalFormat df = new DecimalFormat("##.#####");
DecimalFormat decimalf = new DecimalFormat("##.######");
AlertDialog alert;
SharedPreferences pref;
Editor prefEditor;
String lastpacketsPHP;
// User to determine how many packet the user would like to see.
int userDefinedCount = 5;
/*
* Called when the activity is first created.
*/
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
loadApp();
}
public boolean isNetworkConnected(Context context)
{
ConnectivityManager connectionManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
if (connectionManager.getActiveNetworkInfo() != null && connectionManager.getActiveNetworkInfo().isAvailable() && connectionManager.getActiveNetworkInfo().isConnected())
{
return true;
}
else
{
return false;
}
}
public void showAlert()
{
alert.setTitle("Sorry!");
alert.setMessage("Please connect to the internet to access the full functionality of this app.");
alert.setButton("OK", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
}
});
alert.show();
}
/* public void onResume()
{
super.onResume();
loadApp();
}
public void onRestart()
{
super.onRestart();
loadApp();
}*/
public void loadApp()
{
setContentView(shc_BalloonSat.namespace.R.layout.main);
alert = new AlertDialog.Builder(this).create();
String returned = "";
lastpacketsPHP = "";
pref = getSharedPreferences("shared_prefs", 0);
prefEditor = pref.edit();
prefEditor.putString(lastpacketsPHP, "/* PHP file URL goes here */");
prefEditor.commit();
// These next two lines are used to test the PHP files on the SHC server by determining if PHP is set up correctly.
//prefEditor.putString(lastpacketsPHP, "/* PHP file URL goes here */");
//prefEditor.commit();
if (!isNetworkConnected(this))
{
showAlert();
}
else
{
api = new httpAPI(this);
map = new mapAPI(this);
dialog = new runDialog();
try
{
returned = api.getData();
}
catch (Exception e)
{
Toast.makeText(this, "Error: Unable to receive data at this time.", Toast.LENGTH_SHORT).show();
}
TextView infoTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.info);
infoTV.setText(returned);
assignInfoToInfoTextView();
assignInfoToHistoryTextView();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
MenuInflater inflater = getMenuInflater();
inflater.inflate(shc_BalloonSat.namespace.R.menu.mainmenu, menu);
SubMenu submenu = menu.addSubMenu(0, Menu.FIRST, Menu.NONE, "Preferences");
submenu.add(0, 5, Menu.NONE, "Get Last 5 Packets");
submenu.add(0, 10, Menu.NONE, "Get Last 10 Packets");
submenu.add(0, 20, Menu.NONE, "Get Last 20 Packets");
inflater.inflate(shc_BalloonSat.namespace.R.menu.mainmenu, submenu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle item selection
switch (item.getItemId())
{
case shc_BalloonSat.namespace.R.id.viewKML:
viewKML();
return true;
case 5:
viewLast5Packets();
return true;
case 10:
viewLast10Packets();
return true;
case 20:
viewLast20Packets();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void assignInfoToInfoTextView()
{
TextView infoTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.info);
try
{
String result = api.result.substring(1, api.result.length()-2);
JSONObject json_data = new JSONObject(result);
double altitudeData = json_data.getDouble("altitude");
double altitudeInFeet = altitudeData * 3.281;
String infoText = "Last Known Altitude: " + df.format(altitudeInFeet) + " ft\n";
Double speedData = json_data.optDouble("speed");
if (speedData.isNaN())
{
speedData = 0.00;
}
Double direction = json_data.optDouble("heading");
String directionUnits = " degrees from N";
String directionText = "";
if (direction == 0)
{
directionText = ", N";
}
else if (direction > 0 && direction < 45)
{
directionText = ", N NE";
}
else if (direction == 45)
{
directionText = ", NE";
}
else if (direction > 45 && direction < 90)
{
directionText = ", E NE";
}
else if (direction == 90)
{
directionText = ", E";
}
else if (direction > 90 && direction < 135)
{
directionText = ", E SE";
}
else if (direction == 135)
{
directionText = ", SE";
}
else if (direction > 135 && direction < 180)
{
directionText = ", S SE";
}
else if (direction == 180)
{
directionText = ", S";
}
else if (direction > 180 && direction < 225)
{
directionText = ", S SW";
}
else if (direction == 225)
{
directionText = ", SW";
}
else if (direction > 225 && direction < 270)
{
directionText = ", W SW";
}
else if (direction == 270)
{
directionText = ", W";
}
else if (direction > 270 && direction < 315)
{
directionText = ", W NW";
}
else if (direction == 315)
{
directionText = ", NW";
}
else if (direction > 315 && direction < 360)
{
directionText = ", N NW";
}
else if (direction.isNaN())
{
directionText = " Invalid direction";
}
else
{
}
infoText += "Last Known Velocity: " + df.format(speedData) + " m/s " + direction + directionUnits + directionText + "\n";
double recentLatitudeData = json_data.getDouble("latitude");
infoText += "Last Known Latitude: " + df.format(recentLatitudeData) + "\n";
double recentLongitudeData = json_data.getDouble("longitude");
infoText += "Last Known Longtitude: " + df.format(recentLongitudeData) + "\n";
infoTV.setText(infoText);
}
catch (JSONException e)
{
// TODO Auto-generated catch block
Log.e("<tag>", e.getMessage());
Toast.makeText(this,"Error in (Last Known) method!",Toast.LENGTH_SHORT).show();
}
catch (Exception e)
{
Log.e("<tag>", e.getMessage());
Toast.makeText(this,"Error in (Last Known) method!",Toast.LENGTH_SHORT).show();
}
}
public void assignInfoToHistoryTextView()
{
try
{
JSONArray jArray = new JSONArray(api.result);
TextView historyTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.history);
for (int count = 1; count < userDefinedCount; count++)
{
JSONObject json_data = jArray.getJSONObject(count);
double altitudeData = json_data.getDouble("altitude");
double altitudeInFeet = altitudeData * 3.281;
String historyText = "Altitude: " + decimalf.format(altitudeInFeet) + " ft\n";
Double speedData = json_data.optDouble("speed");
if (speedData.isNaN())
{
speedData = 0.00;
}
Double direction = json_data.optDouble("heading");
String directionUnits = " degrees from N";
String directionText = "";
if (direction == 0)
{
directionText = ", N";
}
else if (direction > 0 && direction < 45)
{
directionText = ", N NE";
}
else if (direction == 45)
{
directionText = ", NE";
}
else if (direction > 45 && direction < 90)
{
directionText = ", E NE";
}
else if (direction == 90)
{
directionText = ", E";
}
else if (direction > 90 && direction < 135)
{
directionText = ", E SE";
}
else if (direction == 135)
{
directionText = ", SE";
}
else if (direction > 135 && direction < 180)
{
directionText = ", S SE";
}
else if (direction == 180)
{
directionText = ", S";
}
else if (direction > 180 && direction < 225)
{
directionText = ", S SW";
}
else if (direction == 225)
{
directionText = ", SW";
}
else if (direction > 225 && direction < 270)
{
directionText = ", W SW";
}
else if (direction == 270)
{
directionText = ", W";
}
else if (direction > 270 && direction < 315)
{
directionText = ", W NW";
}
else if (direction == 315)
{
directionText = ", NW";
}
else if (direction > 315 && direction < 360)
{
directionText = ", N NW";
}
else if (direction.isNaN())
{
directionText = " Invalid direction";
}
else
{
}
if (direction.isNaN())
{
historyText += "Velocity: " + df.format(speedData) + " m/s " + directionText + "\n";
}
else
{
historyText += "Velocity: " + df.format(speedData) + " m/s,\n" + direction + directionUnits + directionText + "\n";
}
double latitudeData = json_data.getDouble("latitude");
historyText += "Latitude: " + df.format(latitudeData) + "\n";
double longitudeData = json_data.getDouble("longitude");
historyText += "Longtitude: " + df.format(longitudeData) + "\n\n";
historyTV.setText(historyText);
}
}
catch (JSONException e)
{
// TODO Auto-generated catch block
Log.e("log_tag", "Error parsing data: " + e.toString());
}
catch(Exception e)
{
Log.e("log_tag", "Error parsing data: " + e.toString());
}
}
void viewLast5Packets()
{
if (!isNetworkConnected(this))
{
showAlert();
}
else
{
userDefinedCount = 5;
prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_5_BS_packets.php");
prefEditor.commit();
assignInfoToInfoTextView();
assignInfoToHistoryTextView();
}
}
void viewLast10Packets()
{
if (!isNetworkConnected(this))
{
showAlert();
}
else
{
userDefinedCount = 10;
prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_10_BS_packets.php");
prefEditor.commit();
assignInfoToInfoTextView();
assignInfoToHistoryTextView();
}
}
void viewLast20Packets()
{
if (!isNetworkConnected(this))
{
showAlert();
}
else
{
userDefinedCount = 20;
prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_20_BS_packets.php");
prefEditor.commit();
assignInfoToInfoTextView();
assignInfoToHistoryTextView();
}
}
public void viewKML()
{
if (!isNetworkConnected(this))
{
showAlert();
}
else
{
map.openKML();
}
}
}
httpAPI.java
package shc_BalloonSat.namespace;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import android.util.Log;
public class httpAPI
{
Shc_BalloonSat_Activity shc;
HttpClient client;
ArrayList<NameValuePair> nameValuePairs;
HttpResponse response;
HttpEntity entity;
InputStream is;
String result = "";
HttpPost httppost;
public httpAPI(Shc_BalloonSat_Activity aContext)
{
shc = aContext;
}
public String getData() throws Exception
{
try
{
client = new DefaultHttpClient();
nameValuePairs = new ArrayList<NameValuePair>();
httppost = new HttpPost(shc.pref.getString(shc.lastpacketsPHP, shc.lastpacketsPHP.toString()));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
response = client.execute(httppost);
entity = response.getEntity();
is = entity.getContent();
}
catch (Exception e)
{
Log.e("log_tag", "Error in HTTP connection: " + e.toString());
}
try
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
is.close();
result = sb.toString();
}
catch(Exception e)
{
Log.e("log_tag", "Error converting result: " + e.toString());
}
return result;
}
}
runDialog.java
package shc_BalloonSat.namespace;
import android.app.ProgressDialog;
import android.os.AsyncTask;
public class runDialog extends AsyncTask<String, Integer, String>
{
Shc_BalloonSat_Activity shc;
httpAPI api;
ProgressDialog progressDialog;
public void onPreExecute()
{
progressDialog = new ProgressDialog(shc);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.show();
}
@Override
protected String doInBackground(String... params)
{
for (int count = 0; count < 20; count++)
{
publishProgress(5);
try
{
api.getData();
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
progressDialog.dismiss();
return null;
}
protected void onProgressUpdate(Integer...progress)
{
progressDialog.incrementProgressBy(progress[0]);
}
protected void onPostExecute()
{
}
}
错误：
org.json.JSONException: Index 5 out of range [0..5)
我得到每次试图从URL获取数据时这个错误。我也可以通过电子邮件发送apk文件给任何想看到它实际上在做什么的人。我也有理由相信，造成这种情况的原因可能也是导致我的ProgressDialog无法显示。任何想法，为什么我可以得到这个错误？
我在主要活动中看不到调用runDialog，也请阅读http://developer.android.com/guide/topics/fundamentals/activities.html#Lifecycle，好像loadApp（）将被调用两次大部分时间你可能不想要。 – mkso 2012-03-14 18:11:13
我相信你是正确的loadApp（）被调用不止一次。从我刚刚在这里阅读：http://stackoverflow.com/questions/8515936/android-activity-life-cycle-difference-between-onpause-and-onstop从我在该线程中理解它将被称为多次。我还在其他语句中调用了runDialog，就像我做了其他类一样。我更新了我的代码以匹配它现在的状态。 – tylerbhughes 2012-03-15 16:26:03