/**
* 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.metamodel.intercept;
/**
* Defines a high-level interface for interceptors in MetaModel.
*
* An intereptor can touch, modify, enhance or do other operations on certain
* object types as they are passed around for execution in MetaModel. There are
* 5 types of concrete interceptors:
*
* @see QueryInterceptor
* @see DataSetInterceptor
* @see RowInsertionInterceptor
* @see TableCreationInterceptor
* @see SchemaInterceptor
*
* @param <E>
* the type of object to intercept
*/
public interface Interceptor<E> {
/**
* Interception method invoked by MetaModel when the intercepted object is
* being activated.
*
* @param input
* the intercepted object
* @return the intercepted object, or a modification of this if the object
* is to be replaced by the interceptor. The returned object must
* not be null.
*/
public E intercept(E input);
}