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1   package org.apache.velocity.tools.view;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.Enumeration;
23  import javax.servlet.ServletContext;
24  
25  /**
26   * <p>Because sometimes you don't care about the difference between a
27   * servlet and a filter.  Why isn't there a common interface for
28   * {@link FilterConfig} and {@link ServletConfig} already? Sheesh.</p>
29   * </p>
30   * <p>
31   * Anyway, this also adds the ability to fake everything if you don't have
32   * either a FilterConfig or a ServletConfig handy. Just implement it and
33   * override the methods that return things you care about. Oh, and if you don't
34   * have any init-params at all, just use {@link JeeContextConfig} as
35   * {@link ServletContext} is the only really essential thing for creating a
36   * {@link VelocityView}.</p>
37   *
38   * @version $Id$
39   * @since 2.0
40   */
41  public interface JeeConfig
42  {
43      /**
44       * Returns an initialization parameter.
45       *
46       * @param name The name of the initialization parameter.
47       * @return The value of the parameter.
48       */
49      String getInitParameter(String name);
50  
51      /**
52       * Looks for the specified init-param in the servlet/filter config
53       * (i.e. calls {@link #getInitParameter}). If no such init-param is
54       * found there, it checks the {@link ServletContext}'s init-params
55       * for the specified parameter.
56       *
57       * @param key The name of the initialization parameter.
58       * @return The value of the initialization parameter.
59       */
60      String findInitParameter(String key);
61  
62      /**
63       * Returns all the parameter names.
64       *
65       * @return The enumeration containing the parameter names.
66       */
67      @SuppressWarnings("unchecked")
68      Enumeration getInitParameterNames();
69  
70      /**
71       * Returns the name of the servlet (or filter) being used.
72       *
73       * @return The name of the configuration.
74       */
75      String getName();
76  
77      /**
78       * Returns the servlet context.
79       *
80       * @return The servlet context.
81       */
82      ServletContext getServletContext();
83  
84  }