Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import java.util.Collection;

import java.util.HashSet;

import java.util.Set;

public class Main {

    public static <T> T getFirstDuplicateValue(Collection<T> collection) {
        Set<T> set = new HashSet<T>();
        // Set#add returns false if the set does not change, which
        // indicates that a duplicate element has been added.
        for (T each : collection) {
            if (!set.add(each))
                return each;
        }
        return null;
    }
}