import java.util.*;public class ArrayListTest { static int index = 0; public static void main(String[] args) {
Integer[] a = new Integer[]{ new Integer(3), new Integer(4), new Integer(2), new Integer(5), new Integer(4), new Integer(5)};
List useList = Arrays.asList(a);
Iterator iterator = useList.iterator();
while(iterator.hasNext() ) {
if( ((Integer)iterator.next()).intValue() == 5) {
System.out.println( index ); } index++; }
} }
如果你ArrayList里面的对象是可排序的,也就是说里面的对象都有实现了Comparable接口的话, Integer[] a = new Integer[]{ new Integer(3), new Integer(4), new Integer(2), new Integer(5), new Integer(4), new Integer(5)};List useList = Arrays.asList(a); Collections.sort(useList); //排序 Collections.binarySearch(useList, new Integer(5));//搜索
static int i=0;
while(useList.hasNext()){
if(useList.next()==max)
return i;
i++;
}
{ static int index = 0;
public static void main(String[] args)
{
Integer[] a = new Integer[]{ new Integer(3), new Integer(4), new Integer(2), new Integer(5), new Integer(4), new Integer(5)};
List useList = Arrays.asList(a);
Iterator iterator = useList.iterator();
while(iterator.hasNext() )
{
if( ((Integer)iterator.next()).intValue() == 5)
{
System.out.println( index );
}
index++;
}
}
}
Integer[] a = new Integer[]{ new Integer(3), new Integer(4),
new Integer(2), new Integer(5),
new Integer(4), new Integer(5)};List useList = Arrays.asList(a);
Collections.sort(useList); //排序
Collections.binarySearch(useList, new Integer(5));//搜索