java.lang.ArrayIndexOutOfBoundsException: length=0; index=0 - Database Reading - Android

Question

I created a method that reads data from a database and puts it in a String array. Android Studio doesn't give syntax errors but when i launch my app the log says:

03-19 16:31:20.938    2518-2518/com.mms.dailypill E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.mms.dailypill, PID: 2518
java.lang.ArrayIndexOutOfBoundsException: length=0; index=0
        at com.mms.dailypill.DBManager.getMedicines(DBManager.java:56)

The method code is:

public String[] getMedicines()
{
    SQLiteDatabase db = dbManager.getWritableDatabase();
    String[] columns = {dbManager.getName(), dbManager.getFormat(), dbManager.getAmount(), dbManager.getExp_date(), dbManager.getTime()};
    Cursor cursor = db.query(dbManager.getTableName(), columns, null, null, null, null, null);
    String[] medicines = {};

    String name, format, exp_date, time;

    int amount;
    int count = 0;
    while(cursor.moveToNext())
    {
        name = cursor.getString(0);
        format = cursor.getString(1);
        amount = cursor.getInt(2);
        exp_date = cursor.getString(3);
        time = cursor.getString(4);
        medicines[count] = "Name: " + name + " Format: " + format + " Amount: " + amount + " Expiration Date: " + exp_date + " Time: " + time;
        count++;
    }
    db.close();
    return medicines;
}

As the log says, the exception is given on the line 56:

time = cursor.getString(4);

The table i read has 6 columns: id, name, format, amount, exp_date, time. I only want to show the entire table without the id column, so when i call the getString() method i start from the index 1 and not from 0.

I really can't understand where the problem is, so if someone can help me i will appreciate it. Thanks in advance!

`String[] medicines = {};` should be `String[] medicines = new String[cursor.getCount()];` and you probably want to check for negative values — Blackbelt, Mar 19 '15 at 16:00
@Blackbelt orb that's answer material right there! Don't be so shy — codeMagic, Mar 19 '15 at 16:07
@Tia just an inside joke between Blackbelt and me. Nothing interesting — codeMagic, May 22 '18 at 12:22

score 12 · Answer 1 · answered Nov 30 '15 at 07:53

java.lang.ArrayIndexOutOfBoundsException: length=0; index=0

even you solve your problem , but I would like to explain why this error occurred , this error happen when you initialize empty array without size , or wrong initialize in this case String[] medicines = {}; its empty with size 0 , then he try add value at first index 0 that not exist , so the solution initialize with his list size String[] medicines = new String[cursor.getCount()];

Notice

An array is a container object that holds a fixed number of values of a single type. The length of an array is established when the array is created. After creation, its length is fixed. You have seen an example of arrays already, in the main method of the "Hello World!" application. This section discusses arrays in greater detail.

Summary

one array created it take fixed size , not like array list you can add as you want.

Source

score 2 · Answer 2 · answered Jan 11 '18 at 19:07

2

for my case I had to request for the length of the array

  if (bill_inputs.length>0){
                    textViewInputType.setText(bill_inputs[0].getInput_name());

                }

so for ur case check the length before doing anything

answered Jan 11 '18 at 19:07

Goodlife

3,822
2
24
23

score 0 · Answer 3 · answered Jul 26 '20 at 13:01

0

If you have changed the database schema and do not update the version of the database then it will lead to the above error.

answered Jul 26 '20 at 13:01

Abhishek Meharia

171
2
4

java.lang.ArrayIndexOutOfBoundsException: length=0; index=0 - Database Reading - Android

3 Answers3

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