/*
 *  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.directory.api.ldap.schema.loader;


import org.apache.directory.api.i18n.I18n;
import org.apache.directory.api.ldap.model.entry.Attribute;
import org.apache.directory.api.ldap.model.entry.Value;
import org.apache.directory.api.ldap.model.exception.LdapException;
import org.apache.directory.api.ldap.model.exception.LdapInvalidAttributeValueException;
import org.apache.directory.api.ldap.model.message.ResultCodeEnum;


/**
 * A class loader that loads classes from an attribute within an entry.
 * 
 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
 */
public class AttributeClassLoader extends ClassLoader
{

    /** The attribute. */
    private Attribute attribute;


    /**
     * Instantiates a new attribute class loader.
     */
    public AttributeClassLoader()
    {
        super( AttributeClassLoader.class.getClassLoader() );
    }


    /**
     * Sets the attribute.
     *
     * @param attribute the new attribute
     * @throws LdapException if the attribute is not binary.
     */
    public void setAttribute( Attribute attribute ) throws LdapException
    {
        if ( attribute.isHumanReadable() )
        {
            throw new LdapInvalidAttributeValueException( ResultCodeEnum.CONSTRAINT_VIOLATION,
                I18n.err( I18n.ERR_10001 ) );
        }

        this.attribute = attribute;
    }


    /**
     * {@inheritDoc}
     */
    public Class<?> findClass( String name ) throws ClassNotFoundException
    {
        byte[] classBytes = null;

        Value<?> value = attribute.get();

        if ( value.isHumanReadable() )
        {
            throw new ClassNotFoundException( I18n.err( I18n.ERR_10002 ) );
        }

        classBytes = value.getBytes();

        return defineClass( name, classBytes, 0, classBytes.length );
    }
}
