KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > pluto > PortletContainerServices


1 /*
2  * Copyright 2003,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.pluto;
17
18 import java.util.HashMap JavaDoc;
19 import java.util.Stack JavaDoc;
20
21 import org.apache.pluto.services.ContainerService;
22 import org.apache.pluto.services.PortletContainerEnvironment;
23
24 /**
25  *
26  */
27 public class PortletContainerServices
28 {
29
30     public static ContainerService get(Class JavaDoc service)
31     {
32         // get current environment from thread local
33 // after prepare has been called
34 Stack JavaDoc currentContainerServiceStack = (Stack JavaDoc)currentContainerService.get();
35
36         if (currentContainerServiceStack.isEmpty())
37         {
38             throw new IllegalStateException JavaDoc("The prepare method was never called");
39         }
40
41         PortletContainerEnvironment environment = (PortletContainerEnvironment)currentContainerServiceStack.peek();
42
43         if (environment == null)
44         {
45             throw new IllegalStateException JavaDoc("The prepare method was never called");
46         }
47
48         return environment.getContainerService(service);
49     }
50
51     public static String JavaDoc getUniqueContainerName()
52     {
53         // get uniqueContainerName stack out of the thread local
54 Stack JavaDoc currentNameStack = (Stack JavaDoc)currentUniqueContainerName.get();
55
56         if (currentNameStack.isEmpty())
57         {
58             throw new IllegalStateException JavaDoc("The prepare method was never called");
59         }
60
61         return(String JavaDoc)currentNameStack.peek();
62     }
63
64     synchronized public static void createReference(String JavaDoc uniqueContainerName, PortletContainerEnvironment environment)
65     {
66         if (containerServices.containsKey(uniqueContainerName))
67         {
68             throw new IllegalArgumentException JavaDoc("The given container name is not unique: "+uniqueContainerName);
69         }
70
71         containerServices.put(uniqueContainerName, environment);
72     }
73
74     synchronized public static void destroyReference(String JavaDoc uniqueContainerName)
75     {
76         // removes environment from Map of possible environments
77 containerServices.remove(uniqueContainerName);
78     }
79
80     /**
81      * This method needs to be called to prepare the portlet container
82      * environment. This allows to have multiple container instances.
83      */
84     synchronized public static void prepare(String JavaDoc uniqueContainerName)
85     {
86         // get container service stack out of the thread local
87 Stack JavaDoc currentContainerServiceStack = (Stack JavaDoc)currentContainerService.get();
88         // add current environment to stack stored in thread local
89 currentContainerServiceStack.push(containerServices.get(uniqueContainerName));
90
91         // get uniqueContainerName stack out of the thread local
92 Stack JavaDoc currentNameStack = (Stack JavaDoc)currentUniqueContainerName.get();
93         // add current uniqueContainerName to stack stored in thread local
94 currentNameStack.push(uniqueContainerName);
95     }
96
97     /**
98      * Releases the current container services.
99      */
100     public static void release()
101     {
102         // remove current environment from thread local
103 // after prepare has been called
104 Stack JavaDoc currentContainerServiceStack = (Stack JavaDoc)currentContainerService.get();
105         if (!currentContainerServiceStack.isEmpty())
106         {
107             currentContainerServiceStack.pop();
108         }
109
110         // remove uniqueContainerName from thread local
111 // after prepare has been called
112 Stack JavaDoc currentNameStack = (Stack JavaDoc)currentUniqueContainerName.get();
113         if (!currentNameStack.isEmpty())
114         {
115             currentNameStack.pop();
116         }
117     }
118
119     // holds a stack of the current environments for temporary use
120 private static ThreadLocal JavaDoc currentContainerService = new StackedThreadLocal();
121     // holds the current environment reference for temporary use
122 private static ThreadLocal JavaDoc currentUniqueContainerName = new StackedThreadLocal();
123
124     // map of possible environments
125 private static HashMap JavaDoc containerServices = new HashMap JavaDoc();
126
127
128
129     private static class StackedThreadLocal extends ThreadLocal JavaDoc
130     {
131         public Object JavaDoc initialValue()
132         {
133             return new Stack JavaDoc();
134         }
135     }
136
137 }
138
Popular Tags