Android: Extract data from ArrayList

Question

I want to extract data from an ArrayList, but the LogCat shows null value.

My code is:

try {
   String sql = "SELECT Cname FROM demo";
   Statement stmt = con.createStatement();
   final ResultSet rs = stmt.executeQuery(sql);
   while (rs.next()) {
      arrData.add(rs.getString("Cname").toString());
   }
   Campaign campaign_data[] = new Campaign[] {
      new Campaign(R.drawable.empty, "Today:"+ arrData.indexOf(0)),
      new Campaign(R.drawable.empty, "This Month:" + arrData.indexOf(1))
   };
} catch() {
}

Please add more details

Psypher
– Psypher

2015-06-20 14:19:55 +00:00
Commented Jun 20, 2015 at 14:19 — Psypher
– Psypher, Commented Jun 20, 2015 at 14:19

Franz Becker · Accepted Answer · 2015-06-20 14:31:22Z

1

Is arrData of type ArrayList?

You seem to be calling indexOf(0) on it which is probably not what you want.

public int indexOf(Object o)

Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index i such that (o==null ? get(i)==null : o.equals(get(i))), or -1 if there is no such index.

I would assume you meant to call get(i), so try the following:

      new Campaign(R.drawable.empty, "Today:"+ arrData.get(0)),
      new Campaign(R.drawable.empty, "This Month:" + arrData.get(1))

edited Jun 20, 2015 at 14:31

answered Jun 20, 2015 at 14:22

Franz Becker

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