I am trying to read data from a CSV file and then send those data to the server for handling, however, when I click the button to read the data from the file and then try to send to server, error exists and my app colses unexpectedly.
Below are the messages in error log:
08-06 17:04:32.168: E/AndroidRuntime(10468): FATAL EXCEPTION: main
08-06 17:04:32.168: E/AndroidRuntime(10468): java.lang.IllegalStateException: Cannot execute task: the task is already running.
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:575)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.os.AsyncTask.execute(AsyncTask.java:534)
08-06 17:04:32.168: E/AndroidRuntime(10468): at Android.Chico.Chico$3.onClick(Chico.java:307)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.view.View.performClick(View.java:4084)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.view.View$PerformClick.run(View.java:16966)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.os.Handler.handleCallback(Handler.java:615)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.os.Handler.dispatchMessage(Handler.java:92)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.os.Looper.loop(Looper.java:137)
08-06 17:04:32.168: E/AndroidRuntime(10468): at android.app.ActivityThread.main(ActivityThread.java:4745)
08-06 17:04:32.168: E/AndroidRuntime(10468): at java.lang.reflect.Method.invokeNative(Native Method)
08-06 17:04:32.168: E/AndroidRuntime(10468): at java.lang.reflect.Method.invoke(Method.java:511)
08-06 17:04:32.168: E/AndroidRuntime(10468): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-06 17:04:32.168: E/AndroidRuntime(10468): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-06 17:04:32.168: E/AndroidRuntime(10468): at dalvik.system.NativeStart.main(Native Method)
I saw same kind of error before, I know this exception may appear as AsyncTask can be executed once, therefore I create a new AsyncTask everytime However, error appears, so I would like to ask what may be the causes?
Here is my code:
public class Chico extends Activity {
GrabURL grab;
Button btnfinish;
Button btninsert;
List<String[]> CSVData = new ArrayList<String[]>();
Boolean Insert = false;
Boolean Continue = false;
int numrecord=0;
@Override
public void onCreate(Bundle savedInstanceState) {
//create the activity
super.onCreate(savedInstanceState);
//set up the layout
setContentView(R.layout.activity_chico);
btninsert = (Button) findViewById(R.id.Insert);
if(new File(Environment.getExternalStorageDirectory()+"/Chico/record.csv").exists()){
btninsert.setVisibility(View.VISIBLE);
}else{
btninsert.setVisibility(View.GONE);
}
btnfinish = (Button) findViewById(R.id.Finish);
btnfinish.setVisibility(View.GONE);
grab = new GrabURL();
btninsert.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if(!Continue){
Insert = true;
Continue = true;
btninsert.setVisibility(View.GONE);
try {
BufferedReader reader = new BufferedReader(new FileReader(Environment.getExternalStorageDirectory()+"/Chico/record.csv"));
try {
String line;
while ((line = reader.readLine()) != null){
String[] RowData = line.split(",");
CSVData.add(RowData);
}
} catch (IOException ex) {
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else{
grab = new GrabURL();
}
if(numrecord==CSVData.size())
btnfinish.setVisibility(View.VISIBLE);
while(numrecord<CSVData.size()){
grab.onPreExecute("TechID", Build.SERIAL);
grab.onPreExecute("ClientID", CSVData.get(numrecord)[0]);
grab.onPreExecute("SiteID", CSVData.get(numrecord)[1]);
grab.onPreExecute("Type", CSVData.get(numrecord)[2]);
grab.onPreExecute("LogTime", CSVData.get(numrecord)[3]);
if(CSVData.get(numrecord)[2]=="Checkin"){
grab.onPreExecute("Remark", "");
}else{
grab.onPreExecute("Remark", CSVData.get(numrecord)[4]);
}
grab.execute(new String[]{"http://192.168.1.150/check.php"});
}
}
});
btnfinish.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
finish();
}
});
}
private class GrabURL extends AsyncTask<String, Void, Void>{
//ArrayList object for storing the string pairs
ArrayList<NameValuePair> nameValuePairs;
public GrabURL() {
//constructor of the class
nameValuePairs = new ArrayList<NameValuePair>();
}
protected void onPreExecute(String key, String value) {
//store the pair of values into the ArrayList
nameValuePairs.add(new BasicNameValuePair(key,value));
}
@Override
protected Void doInBackground(String... urls) {
// TODO Auto-generated method stub
//Operation being executed in another thread
try{
//set up the type of HTTPClient
HttpClient client = new DefaultHttpClient();
//set up the location of the server
HttpPost post = new HttpPost(urls[0]);
//translate form of pairs to UrlEncodedFormEntity
UrlEncodedFormEntity ent = new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8);
//set up the entity being sent by post method
post.setEntity(ent);
//execute the url and post the values
//client.execute(post);
HttpResponse responsePOST = client.execute(post);
HttpEntity resEntity = responsePOST.getEntity();
line = EntityUtils.toString(resEntity);
} catch (Exception e) {
//catch the exception
line = "Can't connect to server";
}
return null;
}
protected void onPostExecute(Void unused) {
if(Insert){
if(line.equals("Check in record has been inserted!") ||
line.equals("Check out record has been inserted!")){
btninsert.setVisibility(View.VISIBLE);
numrecord++;
} else if(line.equals("Can't connect to server")) {
btnfinish.setVisibility(View.VISIBLE);
}
}
}
}
}
