Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Open Source License 

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

public class Main {
    private static final Integer ONE = new Integer(1);

    public static <T> Map<T, Integer> getCardinalityMap(final Collection<T> coll) {
        if (coll == null) {
            return null;
        }

        Map<T, Integer> result = new HashMap<T, Integer>();
        Iterator<T> it = coll.iterator();
        while (it.hasNext()) {
            T t = it.next();
            Integer count = result.get(t);
            if (count == null) {
                result.put(t, ONE);
            } else {
                result.put(t, new Integer(count.intValue() + 1));
            }
        }
        return result;
    }
}