Setting the Selected Items in a JList Component : JList Selection « Swing « Java Tutorial

1. Java Tutorial
2. Swing
3. JList Selection

import javax.swing.JList;

public class Main {
  public static void main(String[] argv) throws Exception {
    String[] items = { "A", "B", "C", "D" };
    JList list = new JList(items);

    // Select the second item
    int start = 1;
    int end = 1;
    list.setSelectionInterval(start, end);
  }
}