Java Map Create map(K key, V value)

Description

Reduces overhead compared to the far more advanced #map(Object) .

License

LGPL

Parameter

Parameter	Description
key	A single key
K	type of the key
value	A single value
V	type of the value

Return

A Modifiable Map with a single entry

Declaration

public static final <K, V> Map<K, V> map(K key, V value) 

Method Source Code

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

import java.util.HashMap;
import java.util.Map;

public class Main {
    /**/*  w ww .j  a v a 2s.c o m*/
     * Reduces overhead compared to the far more advanced {@link #map(Object...)}.
     * 
     * @param key A single key
     * @param <K> type of the key
     * @param value A single value
     * @param <V> type of the value
     * @return A Modifiable Map with a single entry
     */
    public static final <K, V> Map<K, V> map(K key, V value) {
        Map<K, V> map = new HashMap<>();
        map.put(key, value);
        return map;
    }

    /**
     * Converting a list into a map
     * 
     * @param keyValues An even list of key/value pairs to be converted into a map
     * @param <K> type of the keys
     * @param <V> type of the values
     * 
     * @return The resulting map of the values
     * @throws IllegalArgumentException If the number of <code>keyValues</code> is not even
     */
    @SuppressWarnings("unchecked")
    public static final <K, V> Map<K, V> map(Object... keyValues) throws IllegalArgumentException {
        //             length % 2 != 0
        if ((keyValues.length & 0b01) != 0)
            throw new IllegalArgumentException("number of arguments must be even");

        Map<K, V> map = new HashMap<>();
        for (int i = 0; i < keyValues.length; i += 2) {
            K key = (K) keyValues[i];
            V value = (V) keyValues[i + 1];
            map.put(key, value);
        }

        return map;
    }
}

Related

1. createMapFromWebsiteList(String[] websiteList)
2. map(final Entry... entries)
3. map(final Object... keysAndValues)
4. map(final Properties props)
5. map(int initialCapacity)
6. map(K key, V value, Object... keysValues)
7. map(K key, V value, Object... moreKeysAndValues)
8. map(K key0, V value0)
9. map(K key1, V value1, Object... objects)