io.undertow.util.AbstractAttachable Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of undertow-core Show documentation
There is a newer version: 2.3.18.Final
/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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 io.undertow.util;

import java.util.Collections;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Map;

import io.undertow.UndertowMessages;

/**
 * A thing which can have named attachments.
 *
 * @author David M. Lloyd
 */
public abstract class AbstractAttachable implements Attachable {

    private Map, Object> attachments;

    /**
     * {@inheritDoc}
     */
    @Override
    public  T getAttachment(final AttachmentKey key) {
        if (key == null || attachments == null) {
            return null;
        }
        return (T) attachments.get(key);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public  List getAttachmentList(AttachmentKey> key) {
        if (key == null || attachments == null) {
            return Collections.emptyList();
        }
        List list = (List) attachments.get(key);
        if (list == null) {
            return Collections.emptyList();
        }
        return list;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public  T putAttachment(final AttachmentKey key, final T value) {
        if (key == null) {
            throw UndertowMessages.MESSAGES.argumentCannotBeNull("key");
        }
        if(attachments == null) {
            attachments = createAttachmentMap();
        }
        return (T) attachments.put(key, value);
    }

    protected Map, Object> createAttachmentMap() {
        return new IdentityHashMap<>(5);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public  T removeAttachment(final AttachmentKey key) {
        if (key == null || attachments == null) {
            return null;
        }
        return (T) attachments.remove(key);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public  void addToAttachmentList(final AttachmentKey> key, final T value) {
        if (key != null) {
            if(attachments == null) {
                attachments = createAttachmentMap();
            }
            final Map, Object> attachments = this.attachments;
            final AttachmentList list = (AttachmentList) attachments.get(key);
            if (list == null) {
                final AttachmentList newList = new AttachmentList<>(((ListAttachmentKey) key).getValueClass());
                attachments.put(key, newList);
                newList.add(value);
            } else {
                list.add(value);
            }
        }
    }

}