重点是怎么才能调用System.arraycopy方法。

public class Cell {
private int v;

public Cell(int v) {
this.v = v;
}

public String toString() {
return String.valueOf(v);
}
}

ArrayList al = new ArrayList(10);
al.add(new Cell(10));
al.add(new Cell(11));
al.add(new Cell(12));
al.add(new Cell(13));
al.add(new Cell(14));
Cell[] cells = new Cell[al.size()];
cells = al.toArray(cells);
System.out.println("cells=" + Arrays.asList(cells));