Java Collection Find findCommonElementType(Collection collection)

Description

find Common Element Type

License

Apache License

Declaration

public static Class<?> findCommonElementType(Collection collection) 

Method Source Code

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

import java.util.Collection;

import java.util.Iterator;

import java.util.Map;

public class Main {
    public static Class<?> findCommonElementType(Collection collection) {
        if (isEmpty(collection)) {
            return null;
        } else {/*  w  ww.j a v a2s.c  o m*/
            Class candidate = null;
            Iterator i$ = collection.iterator();

            while (i$.hasNext()) {
                Object val = i$.next();
                if (val != null) {
                    if (candidate == null) {
                        candidate = val.getClass();
                    } else if (candidate != val.getClass()) {
                        return null;
                    }
                }
            }

            return candidate;
        }
    }

    public static boolean isEmpty(Collection collection) {
        return collection == null || collection.isEmpty();
    }

    public static boolean isEmpty(Map map) {
        return map == null || map.isEmpty();
    }
}

Related

1. findClass(String name, Collection availableImports, ClassLoader cl)
2. findCommonElementType(Collection collection)
3. findCommonElementType(Collection collection)
4. findCommonElementType(Collection collection)
5. findMax(Collection vals)
6. findMax(Collection vals)