Here you can find the source of search(List extends Comparable super T>> collection, T element)
public static <T> int search(List<? extends Comparable<? super T>> collection, T element)
//package com.java2s; /*//from www . j ava 2 s. c o m This file is part of PH-Tree: A multi-dimensional indexing and storage structure. Copyright (C) 2011-2015 Eidgen?ssische Technische Hochschule Z?rich (ETH Zurich) Institute for Information Systems GlobIS Group Bogdan Vancea, Tilmann Zaeschke zaeschke@inf.ethz.ch or zoodb@gmx.de This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ import java.util.List; public class Main { public static <T> int search(List<? extends Comparable<? super T>> collection, T element) { int index = 0; for (Comparable<? super T> el : collection) { int cmp = el.compareTo(element); if (cmp == 0) { return index; } index++; } return -1; } }