# PDDefaultAttributeObject.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.pdfbox.pdmodel.documentinterchange.logicalstructure;

    import java.util.ArrayList;
    import java.util.Iterator;
    import java.util.List;

    import org.apache.pdfbox.cos.COSBase;
    import org.apache.pdfbox.cos.COSDictionary;
    import org.apache.pdfbox.cos.COSName;

    /**
     * A default attribute object.
     *
     * @author Johannes Koch
     */
    public class PDDefaultAttributeObject extends PDAttributeObject
    {

        /**
         * Default constructor.
         */
        public PDDefaultAttributeObject()
        {
        }

        /**
         * Creates a default attribute object with a given dictionary.
         *
         * @param dictionary the dictionary
         */
        public PDDefaultAttributeObject(COSDictionary dictionary)
        {
            super(dictionary);
        }

        /**
         * Gets the attribute names.
         *
         * @return the attribute names
         */
        public List<String> getAttributeNames()
        {
            List<String> attrNames = new ArrayList<>();
            this.getCOSObject().keySet().stream()
                    .filter(key -> !COSName.O.equals(key))
                    .map(COSName::getName)
                    .forEach(attrNames::add);
            return attrNames;
        }

        /**
         * Gets the attribute value for a given name.
         *
         * @param attrName the given attribute name
         * @return the attribute value for a given name
         */
        public COSBase getAttributeValue(String attrName)
        {
            return this.getCOSObject().getDictionaryObject(attrName);
        }

        /**
         * Gets the attribute value for a given name.
         *
         * @param attrName the given attribute name
         * @param defaultValue the default value
         * @return the attribute value for a given name
         */
        protected COSBase getAttributeValue(String attrName, COSBase defaultValue)
        {
            COSBase value = this.getCOSObject().getDictionaryObject(attrName);
            if (value == null)
            {
                return defaultValue;
            }
            return value;
        }

        /**
         * Sets an attribute.
         *
         * @param attrName the attribute name
         * @param attrValue the attribute value
         */
        public void setAttribute(String attrName, COSBase attrValue)
        {
            COSBase old = this.getAttributeValue(attrName);
            this.getCOSObject().setItem(COSName.getPDFName(attrName), attrValue);
            this.potentiallyNotifyChanged(old, attrValue);
        }

        @Override
        public String toString()
        {
            StringBuilder sb = new StringBuilder().append(super.toString())
                .append(", attributes={");
            Iterator<String> it = this.getAttributeNames().iterator();
            while (it.hasNext())
            {
                String name = it.next();
                sb.append(name).append('=').append(this.getAttributeValue(name));
                if (it.hasNext())
                {
                    sb.append(", ");
                }
            }
            return sb.append('}').toString();
        }

    }