studio.raptor.ddal.common.util.MapUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package studio.raptor.ddal.common.util;
import java.util.Map;
/**
* @author Sam
* @since 3.0.0
*/
public class MapUtils {
/**
* Gets a String from a Map in a null-safe manner.
*
* The String is obtained via toString.
*
* @param the key type
* @param map the map to use
* @param key the key to look up
* @return the value in the Map as a String, null if null map input
*/
public static String getString(final Map map, final K key) {
if (map != null) {
final Object answer = map.get(key);
if (answer != null) {
return answer.toString();
}
}
return null;
}
/**
* Looks up the given key in the given map, converting the result into
* a string, using the default value if the the conversion fails.
*
* @param the key type
* @param map the map whose value to look up
* @param key the key of the value to look up in that map
* @param defaultValue what to return if the value is null or if the
* conversion fails
* @return the value in the map as a string, or defaultValue if the
* original value is null, the map is null or the string conversion fails
*/
public static String getString(final Map map, final K key, final String defaultValue) {
String answer = getString(map, key);
if (answer == null) {
answer = defaultValue;
}
return answer;
}
}