如何删除java.lang.IndexOutOfBoundsException？

Question

I'm new in android app development and I am developing an android app. My app uses array-lists for check-boxes and pending intents. But on execution it is giving the following error on the logcat window:

java.lang.RuntimeException: Unable to start activity ComponentInfo java.lang.IndexOutOfBoundsException: Invalid index 1, size is 0

My partial code is as follows:

public class Labs extends Activity {


    ArrayList <CheckBox> l= new ArrayList <CheckBox>(60);


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


    l.add(1,(CheckBox)findViewById(R.id.checkBox101));
    l.add(2,(CheckBox)findViewById(R.id.checkBox102));
    l.add(3,(CheckBox)findViewById(R.id.checkBox103));
    l.add(4,(CheckBox)findViewById(R.id.checkBox104));
    l.add(5,(CheckBox)findViewById(R.id.checkBox105));
    l.add(6,(CheckBox)findViewById(R.id.checkBox106));
    l.add(7,(CheckBox)findViewById(R.id.checkBox107));
    l.add(8,(CheckBox)findViewById(R.id.checkBox108));
    l.add(9,(CheckBox)findViewById(R.id.checkBox109));
    l.add(10,(CheckBox)findViewById(R.id.checkBox110));
    l.add(11,(CheckBox)findViewById(R.id.checkBox111));
    l.add(12,(CheckBox)findViewById(R.id.checkBox112));
    l.add(13,(CheckBox)findViewById(R.id.checkBox113));
    l.add(14,(CheckBox)findViewById(R.id.checkBox114));
    l.add(15,(CheckBox)findViewById(R.id.checkBox115));
    l.add(16,(CheckBox)findViewById(R.id.checkBox116));
    l.add(17,(CheckBox)findViewById(R.id.checkBox117));
    l.add(18,(CheckBox)findViewById(R.id.checkBox118));
    l.add(19,(CheckBox)findViewById(R.id.checkBox119));
    l.add(20,(CheckBox)findViewById(R.id.checkBox120));
    l.add(21,(CheckBox)findViewById(R.id.checkBox121));
    l.add(22,(CheckBox)findViewById(R.id.checkBox122));
    l.add(23,(CheckBox)findViewById(R.id.checkBox123));
    l.add(24,(CheckBox)findViewById(R.id.checkBox124));
    l.add(25,(CheckBox)findViewById(R.id.checkBox125));
    l.add(26,(CheckBox)findViewById(R.id.checkBox126));
    l.add(27,(CheckBox)findViewById(R.id.checkBox127));
    l.add(28,(CheckBox)findViewById(R.id.checkBox128));
    l.add(29,(CheckBox)findViewById(R.id.checkBox129));
    l.add(30,(CheckBox)findViewById(R.id.checkBox130));
    l.add(31,(CheckBox)findViewById(R.id.checkBox131));
    l.add(32,(CheckBox)findViewById(R.id.checkBox132));
    l.add(33,(CheckBox)findViewById(R.id.checkBox133));
    l.add(34,(CheckBox)findViewById(R.id.checkBox134));
    l.add(35,(CheckBox)findViewById(R.id.checkBox135));
    l.add(36,(CheckBox)findViewById(R.id.checkBox136));
    l.add(37,(CheckBox)findViewById(R.id.checkBox137));
    l.add(38,(CheckBox)findViewById(R.id.checkBox138));
    l.add(39,(CheckBox)findViewById(R.id.checkBox139));
    l.add(40,(CheckBox)findViewById(R.id.checkBox140));
    l.add(41,(CheckBox)findViewById(R.id.checkBox141));
    l.add(42,(CheckBox)findViewById(R.id.checkBox142));
    l.add(43,(CheckBox)findViewById(R.id.checkBox143));
    l.add(44,(CheckBox)findViewById(R.id.checkBox144));
    l.add(45,(CheckBox)findViewById(R.id.checkBox145));
    l.add(46,(CheckBox)findViewById(R.id.checkBox146));
    l.add(47,(CheckBox)findViewById(R.id.checkBox147));
    l.add(48,(CheckBox)findViewById(R.id.checkBox148));
    l.add(49,(CheckBox)findViewById(R.id.checkBox149));
    l.add(50,(CheckBox)findViewById(R.id.checkBox150));
    l.add(51,(CheckBox)findViewById(R.id.checkBox151));
    l.add(52,(CheckBox)findViewById(R.id.checkBox152));
    l.add(53,(CheckBox)findViewById(R.id.checkBox153));
    l.add(54,(CheckBox)findViewById(R.id.checkBox154));
    l.add(55,(CheckBox)findViewById(R.id.checkBox155));
    l.add(56,(CheckBox)findViewById(R.id.checkBox156));
    l.add(57,(CheckBox)findViewById(R.id.checkBox157));
    l.add(58,(CheckBox)findViewById(R.id.checkBox158));
    l.add(59,(CheckBox)findViewById(R.id.checkBox159));
    l.add(60,(CheckBox)findViewById(R.id.checkBox160));

        }





    //Intents
    Intent setVibration = new Intent();
    setVibration.setClass(this, AlarmReciever.class);

    Intent setNormal = new Intent();
    setNormal.setClass(this, RingerMode.class);


    //PENDING INTENTS

    ArrayList <PendingIntent> Lab_V= new ArrayList <PendingIntent>(60);
    ArrayList <PendingIntent> Lab_N= new ArrayList <PendingIntent>(60);

    for(int i=0; i<60; i++)
    {
        Lab_V.add(i+1, PendingIntent.getBroadcast(this, i+1, setVibration,
                PendingIntent.FLAG_UPDATE_CURRENT));
        Lab_N.add(i+1, PendingIntent.getBroadcast(this, i+1, setNormal,
                PendingIntent.FLAG_UPDATE_CURRENT));
    }


    // create the object
    AlarmManager mAlarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);


    for(int i=0; i<60; i++)
    {

        if(l.get(i+1).isChecked()){

             mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP, L[i+1].getTimeInMillis(), 7*24*60*60*1000, Lab_V.get(i+1));
             mAlarmManager.setRepeating(AlarmManager.RTC_WAKEUP, L[i+1].getTimeInMillis()+50*60*1000, 7*24*60*60*1000, Lab_N.get(i+1));


        }
    }

    }

Please help me resolve this error. It'll be a huge help. Thanks in advance.

Answer 1

Add elements like this:

l.add((CheckBox)findViewById(R.id.checkBox101));
l.add((CheckBox)findViewById(R.id.checkBox102));
l.add((CheckBox)findViewById(R.id.checkBox103));
[..]

or

l.add(0, (CheckBox)findViewById(R.id.checkBox101));
l.add(1, (CheckBox)findViewById(R.id.checkBox102));
l.add(2, (CheckBox)findViewById(R.id.checkBox103));
[..]

or least tedious way

for (int i = 101; i <= 160; i++) {
   String viewId = "checkBox" + i;
   l.add((CheckBox) findViewById(getResources().getIdentifier(viewId, "id", getPackageName())));
}

It's because indexes in Java start with 0 . So at the beginning, when the list is empty, when you try to add (in that case it works like insert) item at index 1 using

l.add(1,(CheckBox)findViewById(R.id.checkBox101));

you get IndexOutOfBoundsException , because there is no index 1 , the list is empty, and there is only index 0 where you can insert something, because list indexes in Java start with 0 .

Then you need to change other code to not do unnecessary i+1 like here

  for(int i=0; i<60; i++)
    {
        if(l.get(i+1).isChecked()){
            [...]
        }
    }

Now it should be just:

  for(int i=0; i<60; i++)
    {
        if(l.get(i).isChecked()){
            [...]
        }
    }

Answer 2

As you did not provide the whole source code and did not post the stack trace, this answer is based on assumptions.

Although you initialize the ArrayList l with a capacity of 60, its size is still 0. Adding an element at index 1 is therefore impossible, as stated in the docs .

List indices always start with 0, not with 1. If you really need to start counting with 1, you can add an empty element first.

Answer 3

You have to start at index 0 not index 1. That's why java is giving a error saying index 1 does not exist because index 0 was never initialized.

    l.add(0,(CheckBox)findViewById(R.id.checkBox101));
    l.add(1,(CheckBox)findViewById(R.id.checkBox102));
    .
    .
    .
    l.add(58,(CheckBox)findViewById(R.id.checkBox101));
    l.add(59,(CheckBox)findViewById(R.id.checkBox102));