001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2017 MicroBean.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
014 * implied.  See the License for the specific language governing
015 * permissions and limitations under the License.
016 */
017package org.microbean.configuration.spi.converter;
018
019import java.util.Arrays;
020import java.util.Collections;
021import java.util.Map;
022
023import java.util.stream.Collectors;
024
025import org.microbean.configuration.api.ConversionException;
026
027import org.microbean.configuration.spi.Converter;
028
029public final class StringToMapStringStringConverter extends Converter<Map<String, String>> {
030
031  private static final long serialVersionUID = 1L;
032  
033  @Override
034  public final Map<String, String> convert(String value) {
035    Map<String, String> returnValue = null;
036    if (value != null) {
037      value = value.trim();
038      if (value.isEmpty()) {
039        returnValue = Collections.emptyMap();
040      } else if (value.startsWith("{") && value.endsWith("}")) {
041        value = value.substring(1, value.length() - 1).trim(); // chops off the { and the }
042      }
043      if (value.isEmpty()) {
044        returnValue = Collections.emptyMap();
045      } else {
046        returnValue = Arrays.stream(value.split(","))
047          .map(String::trim)
048          .filter(s -> !s.isEmpty())
049          .map(s -> s.split("="))
050          .collect(Collectors.toMap(a -> a[0].trim(), a -> a[1].trim()));
051      }
052    }
053    return returnValue;
054  }
055  
056}