Package com.cedarsoftware.util

Class MapUtilities

java.lang.Object
com.cedarsoftware.util.MapUtilities
public class MapUtilities extends Object
Usefule utilities for Maps
Author:
Kenneth Partlow
Copyright (c) Cedar Software LLC

Licensed 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.

  • Method Summary

    Modifier and Type
    Method
    Description
    static <T> T
    get(Map<?,T> map, Object key, T def)
    Retrieves a value from a map by key
    static <T extends Throwable>
    Object
    getOrThrow(Map<?,?> map, Object key, T throwable)
    Retrieves a value from a map by key, if value is not found by the given key throws a 'Throwable.' This version allows the value associated to the key to be null, and it still works.
    static boolean
    isEmpty(Map map)
    Returns null safe isEmpty check for Map

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • get

      public static <T> T get(Map<?,T> map, Object key, T def)
      Retrieves a value from a map by key
      Parameters:
      map - Map to retrieve item from
      key - the key whose associated value is to be returned
      def - value to return if item was not found.
      Returns:
      Returns a string value that was found at the location key. If the item is null then the def value is sent back. If the item is not the expected type, an exception is thrown.

    • getOrThrow

      public static <T extends Throwable> Object getOrThrow(Map<?,?> map, Object key, T throwable) throws T
      Retrieves a value from a map by key, if value is not found by the given key throws a 'Throwable.' This version allows the value associated to the key to be null, and it still works. In other words, if the passed in key is within the map, this method will return whatever is associated to the key, including null.
      Type Parameters:
      T - Throwable passed in to be thrown *if* the passed in key is not within the passed in map.
      Parameters:
      map - Map to retrieve item from
      key - the key whose associated value is to be returned
      throwable -
      Returns:
      the value associated to the passed in key from the passed in map, otherwise throw the passed in exception.
      Throws:
      T extends Throwable

    • isEmpty

      public static boolean isEmpty(Map map)
      Returns null safe isEmpty check for Map
      Parameters:
      map - Map to check, can be null
      Returns:
      Returns true if map is empty or null