/*
* $Id: ServletUtil.java 797765 2009-07-25 13:20:26Z 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.servlet.context;
import java.io.IOException;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import org.apache.tiles.ArrayStack;
import org.apache.tiles.TilesApplicationContext;
import org.apache.tiles.TilesContainer;
import org.apache.tiles.access.TilesAccess;
import org.apache.tiles.context.TilesRequestContext;
import org.apache.tiles.context.TilesRequestContextWrapper;
import org.apache.tiles.impl.NoSuchContainerException;
import org.apache.tiles.util.TilesIOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utilities for Tiles servlet support.
*
* @version $Rev: 797765 $ $Date: 2009-07-25 15:20:26 +0200 (sab, 25 lug 2009) $
* @since 2.0.6
*/
public final class ServletUtil {
/**
* The name of the attribute that will contain the compose stack.
*/
public static final String COMPOSE_STACK_ATTRIBUTE_NAME = "org.apache.tiles.template.COMPOSE_STACK";
/**
* Name of the attribute used to store the force-include option.
* @since 2.0.6
*/
public static final String FORCE_INCLUDE_ATTRIBUTE_NAME =
"org.apache.tiles.servlet.context.ServletTilesRequestContext.FORCE_INCLUDE";
/**
* Name of the attribute used to store the current used container.
*/
public static final String CURRENT_CONTAINER_ATTRIBUTE_NAME =
"org.apache.tiles.servlet.context.ServletTilesRequestContext.CURRENT_CONTAINER_KEY";
/**
* Private constructor to avoid instantiation.
*/
private ServletUtil() {
}
/**
* Returns true if forced include of the result is needed.
*
* @param request The HTTP request.
* @return If <code>true</code> the include operation must be forced.
* @since 2.0.6
*/
public static boolean isForceInclude(HttpServletRequest request) {
Boolean retValue = (Boolean) request
.getAttribute(ServletUtil.FORCE_INCLUDE_ATTRIBUTE_NAME);
return retValue != null && retValue.booleanValue();
}
/**
* Sets the option that enables the forced include of the response.
*
* @param request The HTTP request.
* @param forceInclude If <code>true</code> the include operation must be
* forced.
* @since 2.0.6
*/
public static void setForceInclude(HttpServletRequest request,
boolean forceInclude) {
Boolean retValue = Boolean.valueOf(forceInclude);
request.setAttribute(
ServletUtil.FORCE_INCLUDE_ATTRIBUTE_NAME,
retValue);
}
/**
* Returns the default Tiles container.
*
* @param context The servlet context to use.
* @return The default Tiles container.
* @since 2.1.2
*/
public static TilesContainer getContainer(ServletContext context) {
return getContainer(context, TilesAccess.CONTAINER_ATTRIBUTE);
}
/**
* Returns a specific Tiles container.
*
* @param context The servlet context to use.
* @param key The key under which the container is stored. If null, the
* default container will be returned.
* @return The requested Tiles container.
* @since 2.1.2
*/
public static TilesContainer getContainer(ServletContext context, String key) {
if (key == null) {
key = TilesAccess.CONTAINER_ATTRIBUTE;
}
return (TilesContainer) context.getAttribute(key);
}
/**
* Configures the default container to be used in the application.
*
* @param context The servlet context object to use.
* @param container The container object to set.
* @since 2.1.2
*/
public static void setContainer(ServletContext context,
TilesContainer container) {
setContainer(context, container, TilesAccess.CONTAINER_ATTRIBUTE);
}
/**
* Configures the container to be used in the application.
*
* @param context The servlet context object to use.
* @param container The container object to set.
* @param key The key under which the container will be stored.
* @since 2.1.2
*/
public static void setContainer(ServletContext context,
TilesContainer container, String key) {
Logger log = LoggerFactory.getLogger(ServletUtil.class);
if (key == null) {
key = TilesAccess.CONTAINER_ATTRIBUTE;
}
if (container == null) {
if (log.isInfoEnabled()) {
log.info("Removing TilesContext for context: " + context.getClass().getName());
}
context.removeAttribute(key);
}
if (container != null && log.isInfoEnabled()) {
log.info("Publishing TilesContext for context: " + context.getClass().getName());
}
context.setAttribute(key, container);
}
/**
* Sets the current container to use in web pages.
*
* @param request The request to use.
* @param context The servlet context to use.
* @param key The key under which the container is stored.
* @since 2.1.0
*/
public static void setCurrentContainer(ServletRequest request,
ServletContext context, String key) {
TilesContainer container = getContainer(context, key);
if (container != null) {
request.setAttribute(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
} else {
throw new NoSuchContainerException("The container with the key '"
+ key + "' cannot be found");
}
}
/**
* Sets the current container to use in web pages.
*
* @param request The request to use.
* @param context The servlet context to use.
* @param container The container to use as the current container.
* @since 2.1.0
*/
public static void setCurrentContainer(ServletRequest request,
ServletContext context, TilesContainer container) {
if (container != null) {
request.setAttribute(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
} else {
throw new NoSuchContainerException("The container cannot be null");
}
}
/**
* Returns the current container that has been set, or the default one.
*
* @param request The request to use.
* @param context The servlet context to use.
* @return The current Tiles container to use in web pages.
* @since 2.1.0
*/
public static TilesContainer getCurrentContainer(ServletRequest request,
ServletContext context) {
TilesContainer container = (TilesContainer) request
.getAttribute(CURRENT_CONTAINER_ATTRIBUTE_NAME);
if (container == null) {
container = getContainer(context);
request.setAttribute(CURRENT_CONTAINER_ATTRIBUTE_NAME, container);
}
return container;
}
/**
* Wraps a ServletException to create an IOException with the root cause if present.
*
* @param ex The exception to wrap.
* @param message The message of the exception.
* @return The wrapped exception.
* @since 2.1.1
*/
public static IOException wrapServletException(ServletException ex,
String message) {
IOException retValue;
Throwable rootCause = ex.getRootCause();
if (rootCause != null) {
// Replace the ServletException with an IOException, with the root
// cause of the first as the cause of the latter.
retValue = new TilesIOException(message, rootCause);
} else {
retValue = new TilesIOException(message, ex);
}
return retValue;
}
/**
* Returns the compose stack, that is used by the tags to compose
* definitions, attributes, etc.
*
* @param request The HTTP request.
* @return The compose stack.
* @since 2.2.0
*/
@SuppressWarnings("unchecked")
public static ArrayStack<Object> getComposeStack(HttpServletRequest request) {
ArrayStack<Object> composeStack = (ArrayStack<Object>) request.getAttribute(
COMPOSE_STACK_ATTRIBUTE_NAME);
if (composeStack == null) {
composeStack = new ArrayStack<Object>();
request.setAttribute(COMPOSE_STACK_ATTRIBUTE_NAME, composeStack);
}
return composeStack;
}
/**
* Opens a TilesRequestContext until it finds a ServletTilesRequestContext.
*
* @param request The request to open.
* @return The servlet-based request context.
* @throws NotAServletEnvironmentException If a servlet-based request
* context could not be found.
* @since 2.2.0
*/
public static ServletTilesRequestContext getServletRequest(TilesRequestContext request) {
TilesRequestContext currentRequest = request;
while (true) {
if (currentRequest == null) {
throw new NotAServletEnvironmentException("Last Tiles request context is null");
}
if (currentRequest instanceof ServletTilesRequestContext) {
return (ServletTilesRequestContext) currentRequest;
}
if (!(currentRequest instanceof TilesRequestContextWrapper)) {
throw new NotAServletEnvironmentException("Not a Servlet environment, not supported");
}
currentRequest = ((TilesRequestContextWrapper) currentRequest).getWrappedRequest();
}
}
/**
* Gets a servlet context from a TilesApplicationContext.
*
* @param applicationContext The application context to analyze.
* @return The servlet context.
* @throws NotAServletEnvironmentException If the application context is not
* servlet-based.
* @since 2.2.0
*/
public static ServletContext getServletContext(TilesApplicationContext applicationContext) {
if (applicationContext instanceof ServletTilesApplicationContext) {
return (ServletContext) ((ServletTilesApplicationContext) applicationContext).getContext();
}
throw new NotAServletEnvironmentException("Not a Servlet-based environment");
}
}