Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

public class Main {

    public static <T> T first(Collection<T> c) {
        if (isEmpty(c))
            return null;

        if (c instanceof List)
            return (T) ((List<T>) c).get(0);

        Iterator<T> iter = c.iterator();
        if (iter.hasNext()) {
            return iter.next();
        }
        return null;
    }

    public static boolean isEmpty(Collection<? extends Object> c) {
        return c == null || c.size() == 0;
    }

    public static boolean isEmpty(Object[] objs) {
        return objs == null || objs.length == 0;
    }

    public static <T> T get(Collection<T> c, int index) {
        if (isEmpty(c))
            return null;

        if (index < 0 || index >= c.size())
            return null;

        if (c instanceof List)
            return (T) ((List<T>) c).get(index);

        List<? extends T> a = new ArrayList<T>(c);
        return a.get(index);
    }
}