1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.chain.impl;
18
19
20 import org.apache.commons.chain.Command;
21 import org.apache.commons.chain.Context;
22
23
24 /**
25 * <p>Implementation of {@link Command} that simply logs its identifier
26 * and returns.</p>
27 *
28 * @author Craig R. McClanahan
29 * @version $Revision: 480477 $ $Date: 2006-11-29 08:34:52 +0000 (Wed, 29 Nov 2006) $
30 */
31
32 public class NonDelegatingCommand implements Command {
33
34
35 // ------------------------------------------------------------ Constructor
36
37
38 public NonDelegatingCommand() {
39 this("");
40 }
41
42
43 // Construct an instance that will log the specified identifier
44 public NonDelegatingCommand(String id) {
45 this.id = id;
46 }
47
48
49 // ----------------------------------------------------- Instance Variables
50
51
52 // The identifier to log for this Command instance
53 protected String id = null;
54
55 String getId() {
56 return (this.id);
57 }
58
59 public void setId(String id) {
60 this.id = id;
61 }
62
63
64 // -------------------------------------------------------- Command Methods
65
66
67 // Execution method for this Command
68 public boolean execute(Context context) throws Exception {
69
70 if (context == null) {
71 throw new IllegalArgumentException();
72 }
73 log(context, id);
74 return (true);
75
76 }
77
78
79
80 // ------------------------------------------------------ Protected Methods
81
82
83 /**
84 * <p>Log the specified <code>id</code> into a StringBuffer attribute
85 * named "log" in the specified <code>context</code>, creating it if
86 * necessary.</p>
87 *
88 * @param context The {@link Context} into which we log the identifiers
89 * @param id The identifier to be logged
90 */
91 protected void log(Context context, String id) {
92 StringBuffer sb = (StringBuffer) context.get("log");
93 if (sb == null) {
94 sb = new StringBuffer();
95 context.put("log", sb);
96 }
97 if (sb.length() > 0) {
98 sb.append('/');
99 }
100 sb.append(id);
101 }
102
103
104 }