/*
* $Id: TilesAccess.java 680114 2008-07-27 14:40:05Z apetrelli $
*
* 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.tiles.access;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tiles.TilesApplicationContext;
import org.apache.tiles.TilesContainer;
import org.apache.tiles.reflect.ClassUtil;
import java.lang.reflect.Method;
/**
* Provides static access to the tiles container.
*
* @version $Rev: 680114 $ $Date: 2008-07-27 16:40:05 +0200 (Sun, 27 Jul 2008) $
*/
public final class TilesAccess {
/**
* Constructor, private to avoid instantiation.
*/
private TilesAccess() {
}
/**
* The logging object.
*/
private static final Log LOG =
LogFactory.getLog(TilesAccess.class);
/**
* The name of the attribute to use when getting and setting the container
* object in a context.
*/
public static final String CONTAINER_ATTRIBUTE =
"org.apache.tiles.CONTAINER";
/**
* The name of the attribute to get the {@link TilesApplicationContext} from
* a context.
*/
private static final String CONTEXT_ATTRIBUTE =
"org.apache.tiles.APPLICATION_CONTEXT";
/**
* Finds and returns the default Tiles container object, if it was
* previously initialized.
*
* @param context The (application) context object to use.
* @return The container if it has been configured previously, otherwise
* <code>null</code>.
* @see #setContainer(Object, TilesContainer)
*/
public static TilesContainer getContainer(Object context) {
return (TilesContainer) getAttribute(context, CONTAINER_ATTRIBUTE);
}
/**
* Finds and returns a Tiles container object, if it was previously initialized.
*
* @param context The (application) context object to use.
* @return The container if it has been configured previously, otherwise
* <code>null</code>.
* @param key The key under which the container is stored.
* @see #setContainer(Object, TilesContainer)
* @since 2.1.0
*/
public static TilesContainer getContainer(Object context, String key) {
if (key == null) {
key = CONTAINER_ATTRIBUTE;
}
return (TilesContainer) getAttribute(context, key);
}
/**
* Configures the default container to be used in the application.
*
* @param context The (application) context object to use.
* @param container The container object to set.
* @throws TilesAccessException If something goes wrong during manipulation of the
* context.
*/
public static void setContainer(Object context, TilesContainer container) {
setContainer(context, container, CONTAINER_ATTRIBUTE);
}
/**
* Configures the container to be used in the application.
*
* @param context The (application) context object to use.
* @param container The container object to set.
* @param key The key under which the container will be stored.
* @throws TilesAccessException If something goes wrong during manipulation of the
* context.
*/
public static void setContainer(Object context, TilesContainer container, String key) {
if (key == null) {
key = CONTAINER_ATTRIBUTE;
}
if (container == null) {
if (LOG.isInfoEnabled()) {
LOG.info("Removing TilesContext for context: " + context.getClass().getName());
}
removeAttribute(context, key);
}
if (container != null && LOG.isInfoEnabled()) {
LOG.info("Publishing TilesContext for context: " + context.getClass().getName());
}
setAttribute(context, key, container);
}
/**
* Returns the Tiles application context object.
*
* @param context The (application) context to use.
* @return The required Tiles application context.
*/
public static TilesApplicationContext getApplicationContext(Object context) {
return getApplicationContext(context, null);
}
/**
* Returns the Tiles application context object.
*
* @param context The (application) context to use.
* @param key The key under which the container is stored.
* @return The required Tiles application context.
* @since 2.1.0
*/
public static TilesApplicationContext getApplicationContext(Object context, String key) {
TilesContainer container = getContainer(context, key);
if (container != null) {
return container.getApplicationContext();
}
return (TilesApplicationContext) getAttribute(context, CONTEXT_ATTRIBUTE);
}
/**
* Returns an attribute from a context.
*
* @param context The context object to use.
* @param attributeName The name of the attribute to search for.
* @return The object, that is the value of the specified attribute.
*/
private static Object getAttribute(Object context, String attributeName) {
Class<?> contextClass = context.getClass();
Method attrMethod = ClassUtil.getForcedAccessibleMethod(
contextClass, "getAttribute", String.class);
return ClassUtil.invokeMethod(context, attrMethod, attributeName);
}
/**
* Sets an attribute in a context.
*
* @param context The context object to use.
* @param name The name of the attribute to set.
* @param value The value of the attribute to set.
* @throws TilesAccessException If something goes wrong during setting the
* attribute.
*/
private static void setAttribute(Object context, String name, Object value) {
Class<?> contextClass = context.getClass();
Method attrMethod = ClassUtil.getForcedAccessibleMethod(
contextClass, "setAttribute", String.class, Object.class);
ClassUtil.invokeMethod(context, attrMethod, name, value);
}
/**
* Removes an attribute from a context.
*
* @param context The context object to use.
* @param name The name of the attribute to remove.
* @throws TilesAccessException If something goes wrong during removal.
*/
private static void removeAttribute(Object context, String name) {
Class<?> contextClass = context.getClass();
Method attrMethod = ClassUtil.getForcedAccessibleMethod(
contextClass, "removeAttribute", String.class);
ClassUtil.invokeMethod(context, attrMethod, name);
}
}