Create array of string from an Arraylist

Question

I want to get :

String[] phoneNos= {"07064267499","07064267499","07064267499"};

from :

ArrayList<Object> phoneNos = [0803406914, 08167337499, 0803377973] ;

This is my code snippet :

public ArrayList < Object > getPhoneNo() {
    ArrayList < Object > phoneNos = new ArrayList < Object > ();
    try {
        Statement stmt = con.createStatement();
        ResultSet result = stmt.executeQuery("SELECT Phone_No FROM paient_details");
        while (result.next()) {
            phoneNos.add(result.getString(1));
        }
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }

    return phoneNos;
}

Maybe you can take a look at Guava's transform list, as explained here: http://stackoverflow.com/questions/7383624/how-to-transform-listx-to-another-listy — facundofarias, Oct 25 '15 at 11:17

score 2 · Answer 1 · answered Oct 25 '15 at 11:18

2

You can use the toArray() method from your List object :

String[] phoneNosArray = new String[phoneNos.size()];
phoneNosArray = phoneNos.toArray(phoneNosArray);

answered Oct 25 '15 at 11:18

Yassin Hajaj

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score 1 · Answer 2 · answered Oct 25 '15 at 11:17

1

First of all, change your ArrayList to :

ArrayList<String> phoneNos = new ArrayList<String>();

since you store Strings in it.

Then you can get the corresponding array with :

String[] arr = phoneNos.toArray(new String[phoneNos.size()]);

answered Oct 25 '15 at 11:17

Eran

387,369
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702
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@awomtm What do you mean by that? What null was returned? Where? – Eran Oct 25 '15 at 11:55
return arr; gives null. I am a java newbie anyway. – awomtm Oct 25 '15 at 12:00
@awomtm Can you show the actual code giving the error? – Eran Oct 25 '15 at 12:01
Add comment says my code is too long. Pls is there any other way to repost my code – awomtm Oct 25 '15 at 12:17
@awomtm You can edit your question and post it there. – Eran Oct 25 '15 at 12:18

Create array of string from an Arraylist

2 Answers2