对List顺序，逆序，随机排列实例代码
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
public class Teeee {
List list = new LinkedList();
public static void main(String[] args) {
List list = new LinkedList();
for ( int i = 0 ; i < 9 ; i ++ ) {
list.add( " a " + i);
}
Collections.sort(list); // 顺序排列
System.out.println(list);

Collections.shuffle(list); // 混乱的意思
System.out.println(list);

Collections.reverse(list); // 倒序排列
System.out.println(list);

System.out.println(Collections.binarySearch(list, " a5 " )); // 折半查找
}