001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.api.ldap.schema.loader;
021
022
023import java.io.ByteArrayInputStream;
024import java.io.IOException;
025import java.util.HashMap;
026import java.util.Map;
027import java.util.jar.JarEntry;
028import java.util.jar.JarInputStream;
029
030import org.apache.directory.api.i18n.I18n;
031import org.apache.directory.api.ldap.model.entry.Attribute;
032import org.apache.directory.api.ldap.model.entry.Value;
033import org.apache.directory.api.ldap.model.exception.LdapException;
034import org.apache.directory.api.ldap.model.exception.LdapInvalidAttributeValueException;
035import org.apache.directory.api.ldap.model.message.ResultCodeEnum;
036import java.io.ByteArrayOutputStream;
037import java.io.InputStream;
038
039
040/**
041 * A class loader that loads classes from an attribute within an entry.
042 * 
043 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
044 */
045public class AttributeClassLoader extends ClassLoader
046{
047    /** The attribute. */
048    private Attribute attribute;
049
050
051    /**
052     * Instantiates a new attribute class loader.
053     */
054    public AttributeClassLoader()
055    {
056        super( AttributeClassLoader.class.getClassLoader() );
057    }
058
059
060    /**
061     * Sets the attribute.
062     *
063     * @param attribute the new attribute
064     * @throws LdapException if the attribute is not binary.
065     */
066    public void setAttribute( Attribute attribute ) throws LdapException
067    {
068        if ( attribute.isHumanReadable() )
069        {
070            throw new LdapInvalidAttributeValueException( ResultCodeEnum.CONSTRAINT_VIOLATION,
071                I18n.err( I18n.ERR_10001 ) );
072        }
073
074        this.attribute = attribute;
075    }
076
077    
078    /**
079     * Read data from a jar, and write them into a byte[]
080     */
081    private static byte[] getBytes( InputStream input ) throws IOException 
082    {
083        ByteArrayOutputStream result = new ByteArrayOutputStream();
084
085        byte[] buf = new byte[2048];
086        int bytesRead = input.read( buf );
087
088        while ( bytesRead != -1 ) 
089        {
090            result.write( buf, 0, bytesRead );
091            bytesRead = input.read( buf );
092        }
093      
094        result.flush();
095        result.close();
096        
097        return result.toByteArray();
098    }
099
100    
101    private Map<String, Class<?>> loadClasses( byte[] jarBytes ) throws IOException 
102    {
103        Map<String, Class<?>> map = new HashMap<>();
104        
105        try ( JarInputStream jis = new JarInputStream( new ByteArrayInputStream( jarBytes ) ) ) 
106        {
107            JarEntry entry;
108            boolean isJar = false;
109            
110            while ( ( entry = jis.getNextJarEntry() ) != null ) 
111            {
112                String fileName = entry.getName();
113                isJar = true;
114                
115                // Just consider the files ending with .class
116                if ( fileName.endsWith( ".class" ) )
117                {
118                    String className = fileName.substring( 0,  fileName.length() - ".class".length() ).replace( '/', '.' );
119                    byte[] classBytes = getBytes( jis );
120                    
121                    Class<?> clazz = defineClass( className, classBytes, 0, classBytes.length );
122                    map.put( className, clazz );
123                }
124            }
125            
126            if ( !isJar )
127            {
128                return null;
129            }
130        }
131
132        return map;
133    }
134
135    /**
136     * {@inheritDoc}
137     */
138    @Override
139    public Class<?> findClass( String name ) throws ClassNotFoundException
140    {
141        byte[] classBytes;
142
143        Value<?> value = attribute.get();
144
145        if ( value.isHumanReadable() )
146        {
147            throw new ClassNotFoundException( I18n.err( I18n.ERR_10002 ) );
148        }
149
150        classBytes = value.getBytes();
151
152        // May be we are dealing with a JAR ?
153        try 
154        {
155            Map<String, Class<?>> classes = loadClasses( classBytes );
156            
157            if ( classes == null )
158            {
159                // May be a simple class ?
160                return defineClass( name, classBytes, 0, classBytes.length );
161            }
162            
163            for ( Map.Entry<String, Class<?>> entry : classes.entrySet() )
164            {
165                if ( entry.getKey().contains( name ) )
166                {
167                    return entry.getValue();
168                }
169            }
170        }
171        catch ( IOException ioe )
172        {
173            // Ok, may be a pure class
174            return defineClass( name, classBytes, 0, classBytes.length );
175        }
176        
177        return null;
178    }
179}