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.Collections;
import java.util.List;
import java.util.Map;
import java.util.Optional;

import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Main {
    public static <T> Map<String, T> toMap(List<T> list, Function<T, String> getId) {
        return stream(list).collect(Collectors.toMap(getId, Function.identity()));
    }

    public static <T> Stream<T> stream(Collection<T> collection) {
        return Optional.ofNullable(collection).orElseGet(Collections::emptyList).stream();
    }
}