Simple map builder for java using Tuple class I've made before (https://gist.github.com/fupfin/2299564)

MapBuilder.java

package fupfin;

import static fupfin.Tuples.*;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

public class MapBuilder<K, V> {

    private Map<K, V> map = new ConcurrentHashMap<K, V>();

    @SafeVarargs
    public MapBuilder(Tuple2<K, V>... keyValues) {
        for(Tuple2<K, V> keyValue: keyValues)
            put(keyValue);
    }

    public MapBuilder<K, V> put(Tuple2<K, V> keyValue)
    {
        return put(keyValue.v1, keyValue.v2);
    }
    
    public MapBuilder<K, V> put(K key, V value)
    {
        this.map.put(key, value);
        return this;
    }

    public Map<K, V> build()
    {
        return map;
    }

    @SafeVarargs
    public static <K, V> MapBuilder<K, V> builder(Tuple2<K, V>... keyValues)
    {
        return new MapBuilder<K, V>(keyValues);
    }
    
    @SafeVarargs
    public static <K, V> Map<K, V> map(Tuple2<K, V>... keyValues)
    {
        return builder(keyValues).build();
    }
}

MapBuilderTest.java

package fupfin;

import static org.junit.Assert.*;
import static fupfin.MapBuilder.*;
import static fupfin.Tuples.*;

import java.util.Map;
import org.junit.Test;

public class MapBuilderTest {
    
    private final String KEY1 = "k1";
    private final String KEY2 = "k2";
    private final String VALUE1 = "v1";
    private final String VALUE2 = "v2";

    @Test
    public void initialBuilderBuildEmptyMap()
    {
        Map<String, String> map = MapBuilder.<String, String>builder().build();
        assertEquals(0, map.size());
    }
    
    @Test
    public void couldBuildNormalMapWithConstructor()
    {
        Map<String, String> map = builder(tuple(KEY1, VALUE1)).build();
        
        assertEquals(1, map.size());
        assertSame(VALUE1, map.get(KEY1));
        
        map = builder(tuple(KEY1, VALUE1), tuple(KEY2, VALUE2)).build();
        assertEquals(2, map.size());
        assertSame(VALUE2, map.get(KEY2));
    }
    
    @Test
    public void coudBuildMapUsingSetterWithTuple()
    {
        MapBuilder<String, String> builder = MapBuilder.<String, String>builder();
        builder.put(tuple(KEY1, VALUE1));

        Map<String, String> map = builder.build();
        assertEquals(1, map.size());
        assertSame(VALUE1, map.get(KEY1));
        
        map = builder.put(tuple(KEY2, VALUE2)).build();
        assertEquals(2, map.size());
        assertSame(VALUE2, map.get(KEY2));
    }
    
    @Test
    public void couldBuildMapUsingSetterWithKeyAndValue()
    {
        MapBuilder<String, String> builder = MapBuilder.<String, String>builder();
        builder.put(KEY1, VALUE1);
        
        Map<String, String> map = builder.build();
        assertEquals(1, map.size());
        assertSame(VALUE1, map.get(KEY1));
        
        map = builder.put(KEY2, VALUE2).build();
        assertEquals(2, map.size());
        assertSame(VALUE2, map.get(KEY2));
    }
    
    @Test
    public void couldBuildMapAtOnceWithSingleStaticMethod()
    {
        Map<String, String> map = map(tuple(KEY1, VALUE1));
        
        assertEquals(1, map.size());
        assertSame(VALUE1, map.get(KEY1));
        
        map = map(tuple(KEY1, VALUE1), tuple(KEY2, VALUE2));
        assertEquals(2, map.size());
        assertSame(VALUE2, map.get(KEY2));
    }
}