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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.statemachine.event;
21  
22  import org.apache.commons.lang.builder.ToStringBuilder;
23  import org.apache.mina.statemachine.context.StateContext;
24  
25  /**
26   * Represents an event which typically corresponds to a method call on a proxy.
27   * An event has an id and zero or more arguments typically corresponding to
28   * the method arguments. 
29   *
30   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
31   */
32  public class Event {
33      public static final String WILDCARD_EVENT_ID = "*";
34  
35      private final Object id;
36  
37      private final StateContext context;
38  
39      private final Object[] arguments;
40  
41      /**
42       * Creates a new {@link Event} with the specified id and no arguments.
43       * 
44       * @param id the event id.
45       * @param context the {@link StateContext} the event was triggered for.
46       */
47      public Event(Object id, StateContext context) {
48          this(id, context, new Object[0]);
49      }
50  
51      /**
52       * Creates a new {@link Event} with the specified id and arguments.
53       * 
54       * @param id the event id.
55       * @param context the {@link StateContext} the event was triggered for.
56       * @param arguments the event arguments.
57       */
58      public Event(Object id, StateContext context, Object[] arguments) {
59          if (id == null) {
60              throw new IllegalArgumentException("id");
61          }
62          if (context == null) {
63              throw new IllegalArgumentException("context");
64          }
65          if (arguments == null) {
66              throw new IllegalArgumentException("arguments");
67          }
68          this.id = id;
69          this.context = context;
70          this.arguments = arguments;
71      }
72  
73      /**
74       * Returns the {@link StateContext} this {@link Event} was triggered for.
75       * 
76       * @return the {@link StateContext}.
77       */
78      public StateContext getContext() {
79          return context;
80      }
81  
82      /**
83       * Returns the id of this {@link Event}.
84       * 
85       * @return the id.
86       */
87      public Object getId() {
88          return id;
89      }
90  
91      /**
92       * Returns the arguments of this {@link Event}.
93       * 
94       * @return the arguments. Returns an empty array if this {@link Event} has 
95       *         no arguments.
96       */
97      public Object[] getArguments() {
98          return arguments;
99      }
100 
101     public String toString() {
102         return new ToStringBuilder(this).append("id", id).append("context", context).append("arguments", arguments)
103                 .toString();
104     }
105 }