Unable to sort string array in android, Arrays.sort causes fatal exception

Question

I,m trying to read all contacts from phone and try to sort the contact names, but calling this method Arrays.sort(mystring, String.CASE_INSENSITIVE_ORDER) causes fatal exception.

I don't know what the problem is..? Is there any other way to sort an String array in android(java)

public class ContactActivity extends Activity {

/**
 * @param args
 */
public static HashMap<String, String> myHash = new HashMap<String, String>();
public static String[] mystring = new String[10000];
protected static int i = 0;
protected Context context;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.contacts_screen);

    ActionBar actionBar = getActionBar();
    actionBar.setDisplayShowHomeEnabled(true);
    actionBar.setHomeButtonEnabled(true);
    actionBar.setDisplayHomeAsUpEnabled(true);

    //*************************************************
    getContactNumbers(this);
    Log.i("Aravinth", "...before sorting....");
    Arrays.sort(mystring, String.CASE_INSENSITIVE_ORDER);
    //*******************************************************

    final ListView contactLV = (ListView)findViewById(R.id.contactsListView);
    MyListAdapter listViewAdapter = new MyListAdapter(this,R.layout.list_items,myHash,mystring);
    contactLV.setAdapter(listViewAdapter);
    /*
    Arrays.sort(contactData);
    for(int i =0;i<contactData.length;i++)
    {
        Log.d("Aravinth",contactData[i]);
    }
    */
}

public static void getContactNumbers(Context context) {
    String contactNumber = null;
    String nameOfContact = null;
    Uri imageUri;
    int i = 0;

    ContentResolver cr = context.getContentResolver();
    Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null,null, null, null);
        if (cur.getCount() > 0) {
            while (cur.moveToNext()) {
                String id = cur.getString(cur.getColumnIndex(BaseColumns._ID));
                nameOfContact = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));


                if (Integer.parseInt(cur.getString(cur.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))) > 0) {
                    Cursor phones = cr.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,null,ContactsContract.CommonDataKinds.Phone.CONTACT_ID+ " = ?", new String[] { id },null);

                    while (phones.moveToNext()) {
                        if(phones.getInt(phones.getColumnIndex(Phone.TYPE)) == Phone.TYPE_MOBILE)
                        {
                            contactNumber = phones.getString(phones.getColumnIndex(Phone.NUMBER));
                            mystring[i] = nameOfContact;
                            myHash.put(nameOfContact, nameOfContact);
                            Log.i("Aravinth", "...Contact Name ...." + mystring[i] + "...contact Number..." + contactNumber);
                        }
                    }
                    phones.close();
                }
                i++;
            }
        }// end of contact name cursor
        cur.close();
}

}

here is the log

08-03 00:45:25.247: I/Aravinth(676): ...before sorting....
08-03 00:45:25.267: D/AndroidRuntime(676): Shutting down VM
08-03 00:45:25.267: W/dalvikvm(676): threadid=1: thread exiting with uncaught exception (group=0x40a9b210)
08-03 00:45:25.287: E/AndroidRuntime(676): FATAL EXCEPTION: main
08-03 00:45:25.287: E/AndroidRuntime(676): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.arsenic.test01/com.arsenic.test01.ContactActivity}: java.lang.NullPointerException
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread.access$600(ActivityThread.java:127)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.os.Looper.loop(Looper.java:137)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread.main(ActivityThread.java:4448)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.lang.reflect.Method.invokeNative(Native Method)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.lang.reflect.Method.invoke(Method.java:511)
08-03 00:45:25.287: E/AndroidRuntime(676):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823)
08-03 00:45:25.287: E/AndroidRuntime(676):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590)
08-03 00:45:25.287: E/AndroidRuntime(676):  at dalvik.system.NativeStart.main(Native Method)
08-03 00:45:25.287: E/AndroidRuntime(676): Caused by: java.lang.NullPointerException
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.lang.String$CaseInsensitiveComparator.compare(String.java:89)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.lang.String$CaseInsensitiveComparator.compare(String.java:71)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.util.TimSort.binarySort(TimSort.java:261)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.util.TimSort.sort(TimSort.java:204)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.util.TimSort.sort(TimSort.java:169)
08-03 00:45:25.287: E/AndroidRuntime(676):  at java.util.Arrays.sort(Arrays.java:2038)
08-03 00:45:25.287: E/AndroidRuntime(676):  at com.arsenic.test01.ContactActivity.onCreate(ContactActivity.java:45)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.Activity.performCreate(Activity.java:4465)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
08-03 00:45:25.287: E/AndroidRuntime(676):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
08-03 00:45:25.287: E/AndroidRuntime(676):  ... 11 more
08-03 00:45:26.718: I/Process(676): Sending signal. PID: 676 SIG: 9

instead of using such slow algorithm refer to this: http://stackoverflow.com/a/26820544/2252830 — pskink, Aug 02 '15 at 20:07

score 1 · Answer 1 · answered Aug 02 '15 at 19:43

1

You are calling getContactNumbers(this) on MainThread.

You have to use Asynctask for getting contacts and in its postExecute method you should call

Arrays.sort(mystring, String.CASE_INSENSITIVE_ORDER);
MyListAdapter listViewAdapter = new MyListAdapter(this,R.layout.list_items,myHash,mystring);
contactLV.setAdapter(listViewAdapter);

answered Aug 02 '15 at 19:43

Dharmaraj

1,256
13
12

True but has nothing to do with the crash. – Raanan Aug 02 '15 at 19:47
1

in mystring you have no data and you are performing sorting on that. – Dharmaraj Aug 02 '15 at 19:47
it works good but i need to pass context as the parameter which is not possible within AsyncTask() ..... how can do that..? – Aravinth thiyagarajan Aug 02 '15 at 19:59
Instead of context you can use ContactActivity.this within the AsyncTask – Dharmaraj Aug 03 '15 at 02:28

score 1 · Accepted Answer · answered Aug 02 '15 at 19:48

08-03 00:45:25.287: E/AndroidRuntime(676): Caused by: java.lang.NullPointerException

Basically you are creating a big array of nulls and then trying to sort it -> NPE.

Correction Instead of an [] array, use a ArrayList which you can sort with Collections.sort

score 0 · Answer 3 · answered Aug 02 '15 at 19:58

More logs would be helpful, but here are two ideas that might help:

I am not am 100% sure about this, but you might wanna check: You initialize your array with a size 10000 does that not mean that all entries are initialized as null? So if you do not have 10000 or more contacts, the array will have trailing null's, right?
It may be that

nameOfContact = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));

gives null for some contacts. At least the documentation does not explicitly exclude nullas return value.

You could check for that

if (nameOfContact == null) { nameOfContact = ""; }

Unable to sort string array in android, Arrays.sort causes fatal exception

3 Answers3