示例代码

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test1 {

	public static void main(String[] args) throws Exception {
		List<Integer> list = new ArrayList<Integer>();
		list.add(7);
		list.add(2);
		list.add(9);
		System.out.println(list);
		Collections.reverse(list);
		System.out.println(list);
	}
	

}

输出结果

[7, 2, 9]
[9, 2, 7]