/* | |
* Licensed to the Apache Software Foundation (ASF) under one | |
* or more contributor license agreements. See the NOTICE file | |
* distributed with this work for additional information | |
* regarding copyright ownership. The ASF licenses this file | |
* to you under the Apache License, Version 2.0 (the | |
* "License"); you may not use this file except in compliance | |
* with the License. You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, | |
* software distributed under the License is distributed on an | |
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | |
* KIND, either express or implied. See the License for the | |
* specific language governing permissions and limitations | |
* under the License. | |
*/ | |
package org.apache.ki.session.mgt; | |
import org.apache.ki.session.InvalidSessionException; | |
import org.apache.ki.session.ProxiedSession; | |
import org.apache.ki.session.Session; | |
/** | |
* Implementation of the {@link Session Session} interface that proxies another <code>Session</code>, but does not | |
* allow any 'write' operations to the underlying session. It allows 'read' operations only. | |
* <p/> | |
* The <code>Session</code> write operations are defined as follows. A call to any of these methods on this | |
* proxy will immediately result in an {@link InvalidSessionException} being thrown: | |
* | |
* <ul> | |
* <li>{@link org.apache.ki.session.Session#setTimeout(long) Session.setTimeout(long)}</li> | |
* <li>{@link Session#touch() Session.touch()}</li> | |
* <li>{@link Session#stop() Session.stop()}</li> | |
* <li>{@link Session#setAttribute(Object, Object) Session.setAttribute(key,value)}</li> | |
* <li>{@link org.apache.ki.session.Session#removeAttribute(Object) Session.removeAttribute(key)}</li> | |
* </ul> | |
* | |
* <p/> | |
* Any other method invocation not listed above will result in a corresponding call to the underlying <code>Session</code>. | |
* | |
* @author Les Hazlewood | |
* @since 0.9 | |
*/ | |
public class ImmutableProxiedSession extends ProxiedSession { | |
/** | |
* Constructs a new instance of this class proxying the specified <code>Session</code>. | |
* | |
* @param target the target <code>Session</code> to proxy. | |
*/ | |
public ImmutableProxiedSession(Session target) { | |
super(target); | |
} | |
/** | |
* Simply throws an <code>InvalidSessionException</code> indicating that this proxy is immutable. Used | |
* only in the Session's 'write' methods documented in the top class-level JavaDoc. | |
* | |
* @throws InvalidSessionException in all cases - used by the Session 'write' method implementations. | |
*/ | |
protected void throwImmutableException() throws InvalidSessionException { | |
String msg = "This session is immutable and read-only - it cannot be altered. This is usually because " + | |
"the session has been stopped or expired already."; | |
throw new InvalidSessionException(msg); | |
} | |
/** | |
* Immediately {@link #throwImmutableException() throws} an <code>InvalidSessionException</code> in all | |
* cases because this proxy is immutable. | |
*/ | |
public void setTimeout(long maxIdleTimeInMillis) throws InvalidSessionException { | |
throwImmutableException(); | |
} | |
/** | |
* Immediately {@link #throwImmutableException() throws} an <code>InvalidSessionException</code> in all | |
* cases because this proxy is immutable. | |
*/ | |
public void touch() throws InvalidSessionException { | |
throwImmutableException(); | |
} | |
/** | |
* Immediately {@link #throwImmutableException() throws} an <code>InvalidSessionException</code> in all | |
* cases because this proxy is immutable. | |
*/ | |
public void stop() throws InvalidSessionException { | |
throwImmutableException(); | |
} | |
/** | |
* Immediately {@link #throwImmutableException() throws} an <code>InvalidSessionException</code> in all | |
* cases because this proxy is immutable. | |
*/ | |
public void setAttribute(Object key, Object value) throws InvalidSessionException { | |
throwImmutableException(); | |
} | |
/** | |
* Immediately {@link #throwImmutableException() throws} an <code>InvalidSessionException</code> in all | |
* cases because this proxy is immutable. | |
*/ | |
public Object removeAttribute(Object key) throws InvalidSessionException { | |
throwImmutableException(); | |
//we should never ever reach this point due to the exception being thrown. | |
throw new InternalError("This code should never execute - please report this as a bug!"); | |
} | |
} |