src/main/java/wycc/util/ArrayUtils.java
public static <T> int firstIndexOf(T[] items, T item) {
		for (int i = 0; i != items.length; ++i) {
			T ith = items[i];
			if (ith == item || (ith != null && ith.equals(item))) {
				return i;
			}
		}
		return -1;
	}
public static <T> int firstIndexOf(T[] items, T item) {
		for (int i = 0; i != items.length; ++i) {
			T ith = items[i];
			if (ith == item || (ith != null && ith.equals(item))) {
				return i;
			}
		}
		return -1;
	}
Determine the first index of a given item in an array of items, or return
-1 otherwise. Items are compared using the method
<code>Object.equals()</code>. The <code>items</code> array may contain
<code>null</code> values; likewise, <code>item</code> may be
<code>null</code> and will match against other <code>null</code> values.

@param items
@param item
@return