Quelle Optional.java Sprache: JAVA

/*
* 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.el.stream;

import jakarta.el.ELException;
import jakarta.el.LambdaExpression;

import org.apache.el.util.MessageFactory;

public class Optional {

    private final Object obj;

    static final Optional EMPTY = new Optional(null);

    Optional(Object obj) {
        this.obj = obj;
    }

    public Object get() throws ELException {
        if (obj == null) {
            throw new ELException(MessageFactory.get("stream.optional.empty"));
        } else {
            return obj;
        }
    }

    public void ifPresent(LambdaExpression le) {
        if (obj != null) {
            le.invoke(obj);
        }
    }

    public Object orElse(Object other) {
        if (obj == null) {
            return other;
        } else {
            return obj;
        }
    }

    public Object orElseGet(Object le) {
        if (obj == null) {
            // EL 3.0 specification says parameter is LambdaExpression but it
            // may already have been evaluated. If that is the case, the
            // original parameter will have been checked to ensure it was a
            // LambdaExpression before it was evaluated.

            if (le instanceof LambdaExpression) {
                return ((LambdaExpression) le).invoke((Object[]) null);
            } else {
                return le;
            }
        } else {
            return obj;
        }
    }
}

quality92%

¤ Dauer der Verarbeitung: 0.15 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.