import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
public class Main {
public static void main(String[] args) {
int bigNumber = 30001;
String[] bigData = new String[bigNumber];
for (int ii = 0; ii < bigNumber; ii++) {
bigData[ii] = "String " + (ii + 1);
}
JList list = new JList(bigData);
list.setVisibleRowCount(5);
JOptionPane.showMessageDialog(null, new JScrollPane(list));
}
}