org.activiti.engine.impl.util.CollectionUtil Maven / Gradle / Ivy
/* 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.
*/
package org.activiti.engine.impl.util;
import org.activiti.engine.ActivitiIllegalArgumentException;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* helper/convenience methods for working with collections.
*
*/
public class CollectionUtil {
// No need to instantiate
private CollectionUtil() {
}
/**
* Helper method that creates a singleton map.
*
* Alternative for Collections.singletonMap(), since that method returns a generic typed map depending on the input type, but we often need a map.
*/
public static Map singletonMap(String key, Object value) {
Map map = new HashMap();
map.put(key, value);
return map;
}
/**
* Helper method to easily create a map.
*
* Takes as input a varargs containing the key1, value1, key2, value2, etc. Note: although an Object, we will cast the key to String internally.
*/
public static Map map(Object... objects) {
if (objects.length % 2 != 0) {
throw new ActivitiIllegalArgumentException("The input should always be even since we expect a list of key-value pairs!");
}
Map map = new HashMap();
for (int i = 0; i < objects.length; i += 2) {
map.put((String) objects[i], objects[i + 1]);
}
return map;
}
public static boolean isEmpty(@SuppressWarnings("rawtypes") Collection collection) {
return (collection == null || collection.isEmpty());
}
public static boolean isNotEmpty(@SuppressWarnings("rawtypes") Collection collection) {
return !isEmpty(collection);
}
}