从mysql表中获取元素到arraylist

Question

我有一个看起来像这样的ArrayList：

[
1 2011-05-10  1  22.0, 
2 2011-05-10  2  5555.0, 
3 2011-05-11  3  123.0, 
4 2011-05-11  2  212.0, 
5 2011-05-30  1  3000.0, 
6 2011-05-30  1  30.0, 
7 2011-06-06  1  307.0, 
8 2011-06-06  1  307.0, 
9 2011-06-06  1  307.0, 
10 2011-06-08  2  3070.0, 
11 2011-06-03  2  356.0, 
12 2011-05-10  2  100.0, 
13 2011-05-30  1  3500.0, 
14 2011-05-10  3  1000.0, 
15 2011-05-10  3  1000.0, 
16 2011-05-07  1  5000.0, 
17 2011-05-07  4  500.0, 
18 2011-08-07  3  1500.0, 
19 2011-08-08  6  11500.0, 
20 2011-08-08  4  11500.0, 
21 2011-08-08  7  11500.0, 
22 2011-06-07  8  3000.0]

这是我获取此arraylist的代码：

@Override
    public ArrayList<Expenses> getExpenses() {
        ArrayList<Expenses> expenses = new ArrayList<Expenses>();
        try {
            Statement stmt = myConnection.createStatement();
            ResultSet result = stmt.executeQuery("SELECT * FROM expenses");
            while(result.next()){

                Expenses expense = new Expenses();
                expense.setNum(result.getInt(1));
                expense.setPayment(result.getString(2));
                expense.setReceiver(result.getInt(3));
                expense.setValue(result.getDouble(4));

                expenses.add(expense);

                }
        }
            catch (SQLException e){
                 System.out.println(e.getMessage());
             }
        return expenses;
    }

但是我想进入arraylist以便数组的每个元素都不是表的行（我现在拥有的），但是表的每个单独元素都应该是数组的元素（[1，2011-05 -10，1，22.0，2，2011-05-10，2，5555.0，3，2011-05-11，3，123.0，]。有人可以帮我吗？

Answer 1

您可以添加到不同类型的ArrayList元素中的唯一方法是将它们视为常规对象。但是，您已经拥有的代码要优越得多。

@Override
public ArrayList<Object> getExpenses() {
    ArrayList<Object> expenses = new ArrayList<Object>();
    try {
        Statement stmt = myConnection.createStatement();
        ResultSet result = stmt.executeQuery("SELECT * FROM expenses");
        while(result.next()) {

            expenses.add(new Integer(result.getInt(1)));

            expenses.add(result.getString(2));
            expenses.add(new Integer(result.getInt(3)));
            expenses.add(result.getDouble(4));
        }
    }
    catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return expenses;
}