1 /*
2 * $Id$
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 package org.apache.struts.chain.commands.servlet;
22
23 import java.util.HashMap;
24 import java.util.Map;
25
26 import org.apache.struts.action.Action;
27 import org.apache.struts.action.ActionServlet;
28 import org.apache.struts.chain.Constants;
29 import org.apache.struts.chain.commands.util.ClassUtils;
30 import org.apache.struts.chain.contexts.ActionContext;
31 import org.apache.struts.chain.contexts.ServletActionContext;
32 import org.apache.struts.config.ActionConfig;
33 import org.apache.struts.config.ModuleConfig;
34 import org.slf4j.Logger;
35 import org.slf4j.LoggerFactory;
36
37 /**
38 * <p>Concrete implementation of <code>AbstractCreateAction</code> for use in
39 * a Servlet API chain. Expects that the ActionContext passed into it can
40 * safely be cast to <code>ServletActionContext</code>.</p>
41 */
42 public class CreateAction
43 extends org.apache.struts.chain.commands.AbstractCreateAction {
44 // ------------------------------------------------------ Instance Variables
45
46 /**
47 * The {@code Log} instance for this class.
48 */
49 private final Logger log =
50 LoggerFactory.getLogger(CreateAction.class);
51
52 /* :TODO The Action class' dependency on having its "servlet" property set
53 * requires this API-dependent subclass of AbstractCreateAction.
54 */
55 protected synchronized Action getAction(ActionContext context, String type,
56 ActionConfig actionConfig)
57 throws Exception {
58
59 ServletActionContext saContext = (ServletActionContext) context;
60 ActionServlet actionServlet = saContext.getActionServlet();
61
62 ModuleConfig moduleConfig = actionConfig.getModuleConfig();
63 String actionsKey = Constants.ACTIONS_KEY + moduleConfig.getPrefix();
64 @SuppressWarnings("unchecked")
65 Map<String, Action> actions = (Map<String, Action>) context.getApplicationScope().get(actionsKey);
66
67 if (actions == null) {
68 actions = new HashMap<>();
69 context.getApplicationScope().put(actionsKey, actions);
70 }
71
72 Action action = null;
73
74 try {
75 if (actionConfig.isSingleton()) {
76 synchronized (actions) {
77 action = actions.get(type);
78 if (action == null) {
79 action = createAction(context, type);
80 actions.put(type, action);
81 }
82 }
83 } else {
84 action = createAction(context, type);
85 }
86 } catch (Exception e) {
87 log.atError()
88 .setMessage(() -> actionServlet.getInternal().getMessage(
89 "actionCreate", actionConfig.getPath(),
90 actionConfig.toString()))
91 .setCause(e).log();
92 throw e;
93 }
94
95 if (action.getServlet() == null) {
96 action.setServlet(actionServlet);
97 }
98
99 return (action);
100 }
101
102 /**
103 * <p>Invoked by <code>getAction</code> when the <code>Action</code>
104 * actually has to be created. If the instance is already created and
105 * cached, this method will not be called. </p>
106 *
107 * @param context The <code>Context</code> for this request
108 * @param type Name of class to instantiate
109 * @return Instantiated Action class
110 * @throws Exception if there are any problems instantiating the Action
111 * class.
112 * @since Struts 1.3.7
113 */
114 protected Action createAction(ActionContext context, String type) throws Exception {
115 log.info("Initialize action of type: {}", type);
116 return (Action) ClassUtils.getApplicationInstance(type);
117 }
118 }