DispatchUtils.java
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* Copyright 2022 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.servlet.util;
import io.undertow.server.Connectors;
import io.undertow.server.HttpServerExchange;
import io.undertow.servlet.handlers.ServletPathMatch;
import io.undertow.servlet.handlers.ServletRequestContext;
import io.undertow.servlet.spec.HttpServletRequestImpl;
import io.undertow.servlet.spec.HttpServletResponseImpl;
import io.undertow.servlet.spec.ServletContextImpl;
import io.undertow.util.BadRequestException;
import io.undertow.util.ParameterLimitException;
import jakarta.servlet.ServletException;
import java.util.Deque;
import java.util.Map;
import static jakarta.servlet.AsyncContext.ASYNC_CONTEXT_PATH;
import static jakarta.servlet.AsyncContext.ASYNC_MAPPING;
import static jakarta.servlet.AsyncContext.ASYNC_PATH_INFO;
import static jakarta.servlet.AsyncContext.ASYNC_QUERY_STRING;
import static jakarta.servlet.AsyncContext.ASYNC_REQUEST_URI;
import static jakarta.servlet.AsyncContext.ASYNC_SERVLET_PATH;
import static jakarta.servlet.RequestDispatcher.ERROR_EXCEPTION;
import static jakarta.servlet.RequestDispatcher.ERROR_EXCEPTION_TYPE;
import static jakarta.servlet.RequestDispatcher.ERROR_MESSAGE;
import static jakarta.servlet.RequestDispatcher.ERROR_METHOD;
import static jakarta.servlet.RequestDispatcher.ERROR_QUERY_STRING;
import static jakarta.servlet.RequestDispatcher.ERROR_REQUEST_URI;
import static jakarta.servlet.RequestDispatcher.ERROR_SERVLET_NAME;
import static jakarta.servlet.RequestDispatcher.ERROR_STATUS_CODE;
import static jakarta.servlet.RequestDispatcher.FORWARD_CONTEXT_PATH;
import static jakarta.servlet.RequestDispatcher.FORWARD_MAPPING;
import static jakarta.servlet.RequestDispatcher.FORWARD_PATH_INFO;
import static jakarta.servlet.RequestDispatcher.FORWARD_QUERY_STRING;
import static jakarta.servlet.RequestDispatcher.FORWARD_REQUEST_URI;
import static jakarta.servlet.RequestDispatcher.FORWARD_SERVLET_PATH;
import static jakarta.servlet.RequestDispatcher.INCLUDE_CONTEXT_PATH;
import static jakarta.servlet.RequestDispatcher.INCLUDE_MAPPING;
import static jakarta.servlet.RequestDispatcher.INCLUDE_PATH_INFO;
import static jakarta.servlet.RequestDispatcher.INCLUDE_QUERY_STRING;
import static jakarta.servlet.RequestDispatcher.INCLUDE_REQUEST_URI;
import static jakarta.servlet.RequestDispatcher.INCLUDE_SERVLET_PATH;
/**
* <p>Utility class to manage the dispatching parsing of the path. The methods
* fill the exchange, request and response with the needed data for the
* dispatch.</p>
*
* @author rmartinc
*/
public final class DispatchUtils {
private DispatchUtils() {
// Utility static class, no constructor
}
/**
* Perform a forward dispatch to a path assigning everything needed to the
* request, response and exchange.
*
* @param path The path to forward scoped to the ServletContext
* @param requestImpl The request
* @param responseImpl The response
* @param servletContext The servlet context
* @return The match for the path
* @throws ParameterLimitException parameter limit exceeded
* @throws BadRequestException
*/
public static ServletPathMatch dispatchForward(final String path,
final HttpServletRequestImpl requestImpl,
final HttpServletResponseImpl responseImpl,
final ServletContextImpl servletContext) throws ParameterLimitException, BadRequestException {
//only update if this is the first forward
if (requestImpl.getAttribute(FORWARD_REQUEST_URI) == null) {
requestImpl.setAttribute(FORWARD_REQUEST_URI, requestImpl.getRequestURI());
requestImpl.setAttribute(FORWARD_CONTEXT_PATH, requestImpl.getContextPath());
requestImpl.setAttribute(FORWARD_SERVLET_PATH, requestImpl.getServletPath());
requestImpl.setAttribute(FORWARD_PATH_INFO, requestImpl.getPathInfo());
requestImpl.setAttribute(FORWARD_QUERY_STRING, requestImpl.getQueryString());
requestImpl.setAttribute(FORWARD_MAPPING, requestImpl.getHttpServletMapping());
}
final String newRequestPath = assignRequestPath(path, requestImpl, servletContext, false);
final ServletPathMatch pathMatch = servletContext.getDeployment().getServletPaths().getServletHandlerByPath(newRequestPath);
requestImpl.getExchange().getAttachment(ServletRequestContext.ATTACHMENT_KEY).setServletPathMatch(pathMatch);
requestImpl.setServletContext(servletContext);
responseImpl.setServletContext(servletContext);
return pathMatch;
}
/**
* Perform an include dispatch to a path assigning everything needed to the
* request, response and exchange.
*
* @param path The path to include scoped to the ServletContext
* @param requestImpl The request
* @param responseImpl The response
* @param servletContext The servlet context
* @return The match for the path
* @throws ParameterLimitException parameter limit exceeded
* @throws BadRequestException
*/
public static ServletPathMatch dispatchInclude(final String path,
final HttpServletRequestImpl requestImpl,
final HttpServletResponseImpl responseImpl,
final ServletContextImpl servletContext) throws ParameterLimitException, BadRequestException {
final String newRequestPath = assignRequestPath(path, requestImpl, servletContext, true);
final ServletPathMatch pathMatch = servletContext.getDeployment().getServletPaths().getServletHandlerByPath(newRequestPath);
// add the rest of the include attributes for include from the match
requestImpl.setAttribute(INCLUDE_CONTEXT_PATH, servletContext.getContextPath());
requestImpl.setAttribute(INCLUDE_SERVLET_PATH, pathMatch.getMatched());
requestImpl.setAttribute(INCLUDE_PATH_INFO, pathMatch.getRemaining());
requestImpl.setAttribute(INCLUDE_MAPPING, requestImpl.getHttpServletMapping());
return pathMatch;
}
/**
* Perform a error dispatch to a path assigning everything needed to the
* request, response and exchange.
*
* @param path The path to forward scoped to the ServletContext
* @param servletName The servlet name
* @param exception The exception for the error
* @param message The error message
* @param requestImpl The request
* @param responseImpl The response
* @param servletContext The servlet context
* @return The match for the path
* @throws ParameterLimitException parameter limit exceeded
* @throws BadRequestException
*/
public static ServletPathMatch dispatchError(final String path, final String servletName,
final Throwable exception, final String message,
final HttpServletRequestImpl requestImpl,
final HttpServletResponseImpl responseImpl,
final ServletContextImpl servletContext) throws ParameterLimitException, BadRequestException {
//only update if this is the first forward
if (requestImpl.getAttribute(FORWARD_REQUEST_URI) == null) {
requestImpl.setAttribute(FORWARD_REQUEST_URI, requestImpl.getRequestURI());
requestImpl.setAttribute(FORWARD_CONTEXT_PATH, requestImpl.getContextPath());
requestImpl.setAttribute(FORWARD_SERVLET_PATH, requestImpl.getServletPath());
requestImpl.setAttribute(FORWARD_PATH_INFO, requestImpl.getPathInfo());
requestImpl.setAttribute(FORWARD_QUERY_STRING, requestImpl.getQueryString());
requestImpl.setAttribute(FORWARD_MAPPING, requestImpl.getHttpServletMapping());
}
// specific attributes for error
requestImpl.setAttribute(ERROR_REQUEST_URI, requestImpl.getRequestURI());
// Required since Jakarta Servlet 6.1
requestImpl.setAttribute(ERROR_QUERY_STRING, requestImpl.getQueryString());
requestImpl.setAttribute(ERROR_SERVLET_NAME, servletName);
if (exception != null) {
if (exception instanceof ServletException && ((ServletException)exception).getRootCause() != null) {
requestImpl.setAttribute(ERROR_EXCEPTION, ((ServletException) exception).getRootCause());
requestImpl.setAttribute(ERROR_EXCEPTION_TYPE, ((ServletException) exception).getRootCause().getClass());
} else {
requestImpl.setAttribute(ERROR_EXCEPTION, exception);
requestImpl.setAttribute(ERROR_EXCEPTION_TYPE, exception.getClass());
}
}
requestImpl.setAttribute(ERROR_MESSAGE, message);
// Required since Jakarta Servlet 6.1
requestImpl.setAttribute(ERROR_METHOD, requestImpl.getMethod());
requestImpl.setAttribute(ERROR_STATUS_CODE, responseImpl.getStatus());
final String newRequestPath = assignRequestPath(path, requestImpl, servletContext, false);
final ServletPathMatch pathMatch = servletContext.getDeployment().getServletPaths().getServletHandlerByPath(newRequestPath);
requestImpl.getExchange().getAttachment(ServletRequestContext.ATTACHMENT_KEY).setServletPathMatch(pathMatch);
requestImpl.setServletContext(servletContext);
responseImpl.setServletContext(servletContext);
return pathMatch;
}
/**
* Perform an async dispatch to a path assigning everything needed to the
* request, response and exchange.
*
* @param path The path to include scoped to the ServletContext
* @param requestImpl The request
* @param responseImpl The response
* @param servletContext The servlet context
* @return The match for the path
* @throws ParameterLimitException parameter limit exceeded
* @throws BadRequestException
*/
public static ServletPathMatch dispatchAsync(final String path,
final HttpServletRequestImpl requestImpl,
final HttpServletResponseImpl responseImpl,
final ServletContextImpl servletContext) throws ParameterLimitException, BadRequestException {
requestImpl.setAttribute(ASYNC_REQUEST_URI, requestImpl.getOriginalRequestURI());
requestImpl.setAttribute(ASYNC_CONTEXT_PATH, requestImpl.getOriginalContextPath());
requestImpl.setAttribute(ASYNC_SERVLET_PATH, requestImpl.getOriginalServletPath());
requestImpl.setAttribute(ASYNC_PATH_INFO, requestImpl.getOriginalPathInfo());
requestImpl.setAttribute(ASYNC_QUERY_STRING, requestImpl.getOriginalQueryString());
requestImpl.setAttribute(ASYNC_MAPPING, requestImpl.getHttpServletMapping());
final String newRequestPath = assignRequestPath(path, requestImpl, servletContext, false);
final ServletPathMatch pathMatch = servletContext.getDeployment().getServletPaths().getServletHandlerByPath(newRequestPath);
requestImpl.getExchange().getAttachment(ServletRequestContext.ATTACHMENT_KEY).setServletPathMatch(pathMatch);
requestImpl.setServletContext(servletContext);
responseImpl.setServletContext(servletContext);
return pathMatch;
}
private static Map<String, Deque<String>> mergeQueryParameters(final Map<String, Deque<String>> newParams, final Map<String, Deque<String>> oldParams) {
for (Map.Entry<String, Deque<String>> entry : oldParams.entrySet()) {
Deque<String> values = newParams.get(entry.getKey());
if (values == null) {
// add all the values as new params do not contain this key
newParams.put(entry.getKey(), entry.getValue());
} else {
// merge values new params first
for (String v : entry.getValue()) {
if (!values.contains(v)) {
values.add(v);
}
}
}
}
return newParams;
}
private static String assignRequestPath(final String path, final HttpServletRequestImpl requestImpl,
final ServletContextImpl servletContext, final boolean include) throws ParameterLimitException, BadRequestException {
final StringBuilder sb = new StringBuilder();
final HttpServerExchange exchange = requestImpl.getExchange();
// create a fake exchange to parse the path
final HttpServerExchange fake = new HttpServerExchange(exchange.getConnection(),
exchange.getRequestHeaders(), exchange.getResponseHeaders(), exchange.getMaxEntitySize());
Connectors.setExchangeRequestPath(fake, servletContext.getContextPath() + path, sb);
// get the relative path respect to the servlet context as the request path to return
final String newRequestPath = fake.getRequestPath().substring(servletContext.getContextPath().length());
if (include) {
// include does not modify exchange paths, just add the query string and request uri
// the rest of attributes are added via the match later
requestImpl.setAttribute(INCLUDE_QUERY_STRING, fake.getQueryString());
requestImpl.setAttribute(INCLUDE_REQUEST_URI, fake.getRequestURI());
} else {
exchange.setRelativePath(newRequestPath);
exchange.setRequestPath(fake.getRequestPath());
exchange.setRequestURI(fake.getRequestURI());
if (!fake.getQueryString().isEmpty()) {
exchange.setQueryString(fake.getQueryString());
}
}
// both forward and include merge parameters by spec
if (!fake.getQueryString().isEmpty()) {
requestImpl.setQueryParameters(mergeQueryParameters(fake.getQueryParameters(), requestImpl.getQueryParameters()));
}
return newRequestPath;
}
}