archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/content/base/ArchivaContentItem.java

package org.apache.archiva.repository.content.base;

/*
 * 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.
 */

import org.apache.archiva.repository.ManagedRepositoryContent;
import org.apache.archiva.repository.content.ContentItem;
import org.apache.archiva.repository.content.Project;
import org.apache.archiva.repository.content.base.builder.OptBuilder;
import org.apache.archiva.repository.content.base.builder.WithAssetBuilder;
import org.apache.archiva.repository.content.base.builder.WithRepositoryBuilder;
import org.apache.archiva.repository.storage.StorageAsset;
import org.apache.commons.lang3.StringUtils;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

/**
 * Abstract implementation of ContentItem interface.
 * <p>
 * The attribute map is created, when the first values are put to the map.
 */
public abstract class ArchivaContentItem implements ContentItem
{

    private Map<String, String> attributes;
    private ManagedRepositoryContent repository;
    private StorageAsset asset;

    @Override
    public <T extends Project> T adapt( Class<T> clazz )
    {
        return (T) this;
    }

    @Override
    public <T extends Project> boolean supports( Class<T> clazz )
    {
        return clazz != null && clazz.isAssignableFrom( this.getClass( ) );
    }


    /**
     * Does lazy initialization of the attributes map.
     * Returns a unmodifiable map.
     *
     * @return unmodifiable map of attributes
     */
    @Override
    public Map<String, String> getAttributes( )
    {
        if ( this.attributes == null )
        {
            return Collections.emptyMap( );
        }
        else
        {
            return Collections.unmodifiableMap( this.attributes );
        }
    }

    /**
     * Adds a attribute value. The key must not be <code>null</code>.
     *
     * @param key   the attribute key
     * @param value the attribute value
     * @throws IllegalArgumentException if the key is <code>null</code> or empty
     */
    public void putAttribute( String key, String value ) throws IllegalArgumentException
    {
        if ( this.attributes == null )
        {
            this.attributes = new HashMap<>( );
        }
        if ( StringUtils.isEmpty( key ) )
        {
            throw new IllegalArgumentException( "Key value must not be empty or null" );
        }
        this.attributes.put( key, value );
    }

    @Override
    public String getAttribute( String key )
    {
        if ( this.attributes == null )
        {
            return null;
        }
        else
        {
            return this.attributes.get( key );
        }
    }

    @Override
    public ManagedRepositoryContent getRepository( )
    {
        return repository;
    }

    @Override
    public StorageAsset getAsset( )
    {
        return asset;
    }

    @Override
    public boolean equals( Object o )
    {
        if ( this == o ) return true;
        if ( o == null || getClass( ) != o.getClass( ) ) return false;

        ArchivaContentItem that = (ArchivaContentItem) o;

        if ( !repository.equals( that.repository ) ) return false;
        return asset.equals( that.asset );
    }

    @Override
    public int hashCode( )
    {
        int result = repository.hashCode( );
        result = 31 * result + asset.hashCode( );
        return result;
    }


    /// Builder section

    /*
     * Builder implementation for each content item.
     * Should be extended by the subclasses.
     */


    /**
     * Builder for content item. Must be extended by subclasses.
     * The builder uses chained interfaces for building the required attributes. That means you have to set
     * some certain attributes, before you can build the content item instance via the {@link #build()} method.
     * <p>
     * Subclasses should extend from this class and provide the interface/class for the destination item,
     * a interface for the optional attributes and a interface that is returned after the last required attribute is
     * set.
     * <p>
     * The interface for optional attributes should inherit from {@link OptBuilder}
     *
     * @param <I> the item class that should be built
     * @param <O> the class/interface for the optional attributes
     * @param <N> the class/interface for the next (required) attribute after the base attributes are set
     */
    protected abstract static class ContentItemBuilder<I extends ArchivaContentItem, O extends OptBuilder<I, O>, N>
        implements WithRepositoryBuilder, WithAssetBuilder<N>,
        OptBuilder<I, O>
    {

        protected I item;

        protected ContentItemBuilder( I item )
        {
            this.item = item;
        }

        protected abstract O getOptBuilder( );

        protected abstract N getNextBuilder( );

        @Override
        public WithAssetBuilder<N> withRepository( ManagedRepositoryContent repository )
        {
            if ( repository == null )
            {
                throw new IllegalArgumentException( "Repository may not be null" );
            }
            ( (ArchivaContentItem) item ).repository = repository;
            return this;
        }

        @Override
        public N withAsset( StorageAsset asset )
        {
            if ( asset == null )
            {
                throw new IllegalArgumentException( "Asset may not be null" );
            }
            ( (ArchivaContentItem) item ).asset = asset;
            return getNextBuilder( );
        }

        @Override
        public O withAttribute( String key, String value )
        {
            if ( StringUtils.isEmpty( key ) )
            {
                throw new IllegalArgumentException( "Attribute key may not be null" );
            }
            item.putAttribute( key, value );
            return getOptBuilder( );
        }

        protected void setRepository( ManagedRepositoryContent repository )
        {
            ( (ArchivaContentItem) item ).repository = repository;
        }

        @Override
        public I build( )
        {
            return item;
        }

    }

    @Override
    public boolean exists( )
    {
        return asset.exists( );
    }
}