ServletUtil.java
/*
* Copyright 2023 Web-Legacy
*
* Licensed 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.request.jakarta.servlet;
import java.io.IOException;
import org.apache.tiles.request.ApplicationAccess;
import org.apache.tiles.request.ApplicationContext;
import org.apache.tiles.request.Request;
import org.apache.tiles.request.RequestWrapper;
import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
/**
* Utilities for Tiles request servlet support.
*
* <p>Copied from Apache tiles-request-servlet 1.0.7 and adapted for
* Jakarta EE 9.</p>
*/
public final class ServletUtil {
/**
* Constructor.
*/
private ServletUtil() {
}
/**
* 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.
*/
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 IOException(message, rootCause);
} else {
retValue = new IOException(message, ex);
}
return retValue;
}
/**
* Returns the application context getting it from the servlet context. It
* must be first saved creating a {@link ServletApplicationContext} and
* using {@link ApplicationAccess#register(ApplicationContext)}.
*
* @param servletContext The servlet context.
*
* @return The application context, if found, {@code null} otherwise.
*/
public static ApplicationContext getApplicationContext(
ServletContext servletContext) {
return (ApplicationContext) servletContext
.getAttribute(ApplicationAccess.APPLICATION_CONTEXT_ATTRIBUTE);
}
/**
* 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.
*/
public static ServletRequest getServletRequest(Request request) {
Request currentRequest = request;
while (true) {
if (currentRequest == null) {
throw new NotAServletEnvironmentException(
"Last Tiles request context is null");
}
if (currentRequest instanceof ServletRequest) {
return (ServletRequest) currentRequest;
}
if (!(currentRequest instanceof RequestWrapper)) {
throw new NotAServletEnvironmentException(
"Not a Servlet environment, not supported");
}
currentRequest = ((RequestWrapper)
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.
*/
public static ServletContext getServletContext(
ApplicationContext applicationContext) {
if (applicationContext instanceof ServletApplicationContext) {
return (ServletContext) ((ServletApplicationContext)
applicationContext).getContext();
}
throw new NotAServletEnvironmentException(
"Not a Servlet-based environment");
}
}