org.ldp4j.application.kernel.persistence.jpa.AttachmentCollection.java Source code

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Here is the source code for org.ldp4j.application.kernel.persistence.jpa.AttachmentCollection.java

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/**
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   This file is part of the LDP4j Project:
 *     http://www.ldp4j.org/
 *
 *   Center for Open Middleware
 *     http://www.centeropenmiddleware.com/
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Copyright (C) 2014-2016 Center for Open Middleware.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   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.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Artifact    : org.ldp4j.framework:ldp4j-application-kernel-jpa:0.2.1
 *   Bundle      : ldp4j-application-kernel-jpa-0.2.1.jar
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 */
package org.ldp4j.application.kernel.persistence.jpa;

import static com.google.common.base.Preconditions.checkState;

import java.util.List;
import java.util.Map;

import org.ldp4j.application.kernel.resource.Attachment;
import org.ldp4j.application.kernel.resource.ResourceId;

import com.google.common.collect.Maps;

final class AttachmentCollection {

    private final Map<String, JPAAttachment> indexByAttachmentId;

    private final Map<ResourceId, JPAAttachment> indexByResourceId;

    private List<JPAAttachment> collection;

    AttachmentCollection() {
        this.indexByAttachmentId = Maps.newLinkedHashMap();
        this.indexByResourceId = Maps.newLinkedHashMap();
    }

    private void indexAttachment(JPAAttachment attachment) {
        this.indexByAttachmentId.put(attachment.id(), attachment);
        ResourceId resourceId = attachment.resourceId();
        if (resourceId != null) {
            this.indexByResourceId.put(resourceId, attachment);
        }
    }

    void addAttachment(JPAAttachment attachment) {
        this.collection.add(attachment);
        indexAttachment(attachment);
    }

    boolean removeAttachment(Attachment attachment) {
        JPAAttachment jpaAttachment = this.indexByAttachmentId.get(attachment.id());
        if (jpaAttachment != null) {
            jpaAttachment.unbind();
        }
        return jpaAttachment != null;
    }

    JPAAttachment attachmendByResourceId(ResourceId resourceId) {
        return this.indexByResourceId.get(resourceId);
    }

    JPAAttachment attachmentById(String attachmentId) {
        return this.indexByAttachmentId.get(attachmentId);
    }

    void checkNotAttached(String attachmentId, ResourceId resourceId) {
        checkState(!this.indexByResourceId.containsKey(resourceId), "Resource '%s' is already attached",
                resourceId);
        JPAAttachment attachment = this.indexByAttachmentId.get(attachmentId);
        checkState(attachment != null, "Unknown attachment '%s'", attachmentId);
        checkState(attachment.resourceId() == null, "A resource is already attached as '%s'", attachmentId);
    }

    void init(List<JPAAttachment> resourceAttachments) {
        this.collection = resourceAttachments;
        for (JPAAttachment attachment : this.collection) {
            indexAttachment(attachment);
        }
    }

}