org.apache.logging.log4j.util.LambdaUtil 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 org.apache.logging.log4j.util;
import org.apache.logging.log4j.message.Message;
import org.apache.logging.log4j.message.MessageFactory;
/**
* Utility class for lambda support.
*/
public final class LambdaUtil {
/**
* Private constructor: this class is not intended to be instantiated.
*/
private LambdaUtil() {
}
/**
* Converts an array of lambda expressions into an array of their evaluation results.
*
* @param suppliers an array of lambda expressions or {@code null}
* @return an array containing the results of evaluating the lambda expressions (or {@code null} if the suppliers
* array was {@code null}
*/
public static Object[] getAll(final Supplier... suppliers) {
if (suppliers == null) {
return null;
}
final Object[] result = new Object[suppliers.length];
for (int i = 0; i < result.length; i++) {
result[i] = get(suppliers[i]);
}
return result;
}
/**
* Returns the result of evaluating the specified function. If the supplied value is of type Message, this method
* returns the result of calling {@code #getFormattedMessage} on that Message.
* @param supplier a lambda expression or {@code null}
* @return the results of evaluating the lambda expression (or {@code null} if the supplier
* was {@code null}
*/
public static Object get(final Supplier supplier) {
if (supplier == null) {
return null;
}
final Object result = supplier.get();
return result instanceof Message ? ((Message) result).getFormattedMessage() : result;
}
/**
* Returns the Message supplied by the specified function.
* @param supplier a lambda expression or {@code null}
* @return the Message resulting from evaluating the lambda expression (or {@code null} if the supplier was
* {@code null}
*/
public static Message get(final MessageSupplier supplier) {
if (supplier == null) {
return null;
}
return supplier.get();
}
/**
* Returns a Message, either the value supplied by the specified function, or a new Message created by the specified
* Factory.
* @param supplier a lambda expression or {@code null}
* @return the Message resulting from evaluating the lambda expression or the Message created by the factory for
* supplied values that are not of type Message
*/
public static Message getMessage(final Supplier supplier, final MessageFactory messageFactory) {
if (supplier == null) {
return null;
}
final Object result = supplier.get();
return result instanceof Message ? (Message) result : messageFactory.newMessage(result);
}
}