001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.spi;
018    
019    import java.io.InputStream;
020    
021    /**
022     * A class resolver for loading classes in a loosly coupled manner to cater for different platforms such
023     * as standalone, web container, j2ee container and OSGi platforms.
024     */
025    public interface ClassResolver {
026    
027        /**
028         * Resolves the given class by its name
029         *
030         * @param name full qualified name of class
031         * @return the class if resolved, <tt>null</tt> if not found.
032         */
033        Class resolveClass(String name);
034    
035        /**
036         * Resolves the given class by its name
037         *
038         * @param name full qualified name of class
039         * @param type the expected type of the class
040         * @return the class if resolved, <tt>null</tt> if not found.
041         */
042        <T> Class<T> resolveClass(String name, Class<T> type);
043    
044        /**
045         * Resolves the given class by its name
046         *
047         * @param name full qualified name of class
048         * @param loader use the provided class loader
049         * @return the class if resolved, <tt>null</tt> if not found.
050         */
051        Class resolveClass(String name, ClassLoader loader);
052    
053        /**
054         * Resolves the given class by its name
055         *
056         * @param name full qualified name of class
057         * @param type the expected type of the class
058         * @param loader use the provided class loader
059         * @return the class if resolved, <tt>null</tt> if not found.
060         */
061        <T> Class<T> resolveClass(String name, Class<T> type, ClassLoader loader);
062    
063        /**
064         * Resolves the given class by its name
065         *
066         * @param name full qualified name of class
067         * @return the class if resolved, <tt>null</tt> if not found.
068         * @throws ClassNotFoundException is thrown if class not found
069         */
070        Class resolveMandatoryClass(String name) throws ClassNotFoundException;
071    
072        /**
073         * Resolves the given class by its name
074         *
075         * @param name full qualified name of class
076         * @param type the expected type of the class
077         * @return the class if resolved, <tt>null</tt> if not found.
078         * @throws ClassNotFoundException is thrown if class not found
079         */
080        <T> Class<T> resolveMandatoryClass(String name, Class<T> type) throws ClassNotFoundException;
081    
082        /**
083         * Resolves the given class by its name
084         *
085         * @param name full qualified name of class
086         * @return the class if resolved, <tt>null</tt> if not found.
087         * @param loader use the provided class loader
088         * @throws ClassNotFoundException is thrown if class not found
089         */
090        Class resolveMandatoryClass(String name, ClassLoader loader) throws ClassNotFoundException;
091    
092        /**
093         * Resolves the given class by its name
094         *
095         * @param name full qualified name of class
096         * @param type the expected type of the class
097         * @param loader use the provided class loader
098         * @return the class if resolved, <tt>null</tt> if not found.
099         * @throws ClassNotFoundException is thrown if class not found
100         */
101        <T> Class<T> resolveMandatoryClass(String name, Class<T> type, ClassLoader loader) throws ClassNotFoundException;
102    
103        /**
104         * Loads the given resource as a stream
105         * @param uri the uri of the resource
106         * @return as a stream
107         */
108        InputStream loadResourceAsStream(String uri);
109    
110    }