MapBuilder.java

package ru.semiot.platform.apigateway.utils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class MapBuilder {

  private final Map<String, Object> map;

  private MapBuilder() {
    this.map = new HashMap<>();
  }

  public static MapBuilder newMap() {
    return new MapBuilder();
  }

  public MapBuilder put(String key, Object... values) {
    if (map.containsKey(key)) {
      Object o = map.get(key);
      if (o instanceof List) {
        List<Object> vs = (List<Object>) o;
        vs.addAll(Arrays.asList(values));
        map.put(key, vs);
      } else {
        List<Object> vs = new ArrayList<>();
        vs.add(o);
        vs.addAll(Arrays.asList(values));
        map.put(key, vs);
      }
    } else {
      if (values.length > 1) {
        map.put(key, Arrays.asList(values));
      }
      if (values.length == 1) {
        map.put(key, values[0]);
      }
    }

    return this;
  }

  public Map<String, Object> build() {
    return map;
  }

}