/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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 com.vaadin.server;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.annotations.VaadinServletConfiguration.InitParameterName;
import com.vaadin.sass.internal.ScssStylesheet;
import com.vaadin.server.communication.ServletUIInitHandler;
import com.vaadin.shared.ApplicationConstants;
import com.vaadin.shared.JsonConstants;
import com.vaadin.shared.Version;
import com.vaadin.ui.UI;
import com.vaadin.util.CurrentInstance;
import elemental.json.Json;
import elemental.json.JsonArray;
import elemental.json.JsonObject;
@SuppressWarnings("serial")
public class VaadinServlet extends HttpServlet implements Constants {
private class ScssCacheEntry implements Serializable {
private final String css;
private final List<String> sourceUris;
private final long timestamp;
private final String scssFileName;
public ScssCacheEntry(String scssFileName, String css,
List<String> sourceUris) {
this.scssFileName = scssFileName;
this.css = css;
this.sourceUris = sourceUris;
timestamp = getLastModified();
}
public ScssCacheEntry(JsonObject json) {
css = json.getString("css");
timestamp = Long.parseLong(json.getString("timestamp"));
sourceUris = new ArrayList<>();
JsonArray uris = json.getArray("uris");
for (int i = 0; i < uris.length(); i++) {
sourceUris.add(uris.getString(i));
}
// Not set for cache entries read from disk
scssFileName = null;
}
public String asJson() {
JsonArray uris = Json.createArray();
for (String uri : sourceUris) {
uris.set(uris.length(), uri);
}
JsonObject object = Json.createObject();
object.put("version", Version.getFullVersion());
object.put("timestamp", Long.toString(timestamp));
object.put("uris", uris);
object.put("css", css);
return object.toJson();
}
public String getCss() {
return css;
}
private long getLastModified() {
long newest = 0;
for (String uri : sourceUris) {
File file = new File(uri);
URL resource = getService().getClassLoader().getResource(uri);
long lastModified = -1L;
if (file.exists()) {
lastModified = file.lastModified();
} else if (resource != null
&& resource.getProtocol().equals("file")) {
try {
file = new File(resource.toURI());
if (file.exists()) {
lastModified = file.lastModified();
}
} catch (URISyntaxException e) {
getLogger().log(Level.WARNING,
"Could not resolve timestamp for " + resource,
e);
}
}
if (lastModified == -1L && resource == null) {
/*
* Ignore missing files found in the classpath, report
* problem and abort for other files.
*/
getLogger().log(Level.WARNING,
"Could not resolve timestamp for {0}, Scss on the fly caching will be disabled",
uri);
// -1 means this cache entry will never be valid
return -1;
}
newest = Math.max(newest, lastModified);
}
return newest;
}
public boolean isStillValid() {
if (timestamp == -1) {
/*
* Don't ever bother checking anything if files used during the
* compilation were gone before the cache entry was created.
*/
return false;
} else if (timestamp != getLastModified()) {
/*
* Would in theory still be valid if the last modification is
* before the recorded timestamp, but that would still mean that
* something has changed since we last checked, so let's
* invalidate in that case as well to be on the safe side.
*/
return false;
} else {
return true;
}
}
public String getScssFileName() {
return scssFileName;
}
}
private VaadinServletService servletService;
/**
* Called by the servlet container to indicate to a servlet that the servlet
* is being placed into service.
*
* @param servletConfig
* the object containing the servlet's configuration and
* initialization parameters
* @throws ServletException
* if an exception has occurred that interferes with the
* servlet's normal operation.
*/
@Override
public void init(javax.servlet.ServletConfig servletConfig)
throws ServletException {
CurrentInstance.clearAll();
super.init(servletConfig);
Properties initParameters = new Properties();
readUiFromEnclosingClass(initParameters);
readConfigurationAnnotation(initParameters);
// Read default parameters from server.xml
final ServletContext context = servletConfig.getServletContext();
for (final Enumeration<String> e = context.getInitParameterNames(); e
.hasMoreElements();) {
final String name = e.nextElement();
initParameters.setProperty(name, context.getInitParameter(name));
}
// Override with application config from web.xml
for (final Enumeration<String> e = servletConfig
.getInitParameterNames(); e.hasMoreElements();) {
final String name = e.nextElement();
initParameters.setProperty(name,
servletConfig.getInitParameter(name));
}
DeploymentConfiguration deploymentConfiguration = createDeploymentConfiguration(
initParameters);
try {
servletService = createServletService(deploymentConfiguration);
} catch (ServiceException e) {
throw new ServletException("Could not initialize VaadinServlet", e);
}
// Sets current service even though there are no request and response
servletService.setCurrentInstances(null, null);
servletInitialized();
CurrentInstance.clearAll();
}
private void readUiFromEnclosingClass(Properties initParameters) {
Class<?> enclosingClass = getClass().getEnclosingClass();
if (enclosingClass != null
&& UI.class.isAssignableFrom(enclosingClass)) {
initParameters.put(VaadinSession.UI_PARAMETER,
enclosingClass.getName());
}
}
private void readConfigurationAnnotation(Properties initParameters)
throws ServletException {
VaadinServletConfiguration configAnnotation = UIProvider
.getAnnotationFor(getClass(), VaadinServletConfiguration.class);
if (configAnnotation != null) {
Method[] methods = VaadinServletConfiguration.class
.getDeclaredMethods();
for (Method method : methods) {
InitParameterName name = method
.getAnnotation(InitParameterName.class);
assert name != null : "All methods declared in VaadinServletConfiguration should have a @InitParameterName annotation";
try {
Object value = method.invoke(configAnnotation);
String stringValue;
if (value instanceof Class<?>) {
stringValue = ((Class<?>) value).getName();
} else {
stringValue = value.toString();
}
if (VaadinServlet.PARAMETER_WIDGETSET.equals(name.value())
&& method.getDefaultValue().equals(stringValue)) {
// Do not set the widgetset to anything so that the
// framework can fallback to the default. Setting
// anything to the init parameter will force that into
// use and e.g. AppWidgetset will not be used even
// though it is found.
continue;
}
initParameters.setProperty(name.value(), stringValue);
} catch (Exception e) {
// This should never happen
throw new ServletException(
"Could not read @VaadinServletConfiguration value "
+ method.getName(),
e);
}
}
}
}
protected void servletInitialized() throws ServletException {
// Empty by default
}
/**
* Gets the currently used Vaadin servlet. The current servlet is
* automatically defined when initializing the servlet and when processing
* requests to the server (see {@link ThreadLocal}) and in
* {@link VaadinSession#access(Runnable)} and {@link UI#access(Runnable)}.
* In other cases, (e.g. from background threads), the current servlet is
* not automatically defined.
* <p>
* The current servlet is derived from the current service using
* {@link VaadinService#getCurrent()}
*
* @return the current Vaadin servlet instance if available, otherwise
* <code>null</code>
*
* @since 7.0
*/
public static VaadinServlet getCurrent() {
VaadinService vaadinService = CurrentInstance.get(VaadinService.class);
if (vaadinService instanceof VaadinServletService) {
VaadinServletService vss = (VaadinServletService) vaadinService;
return vss.getServlet();
} else {
return null;
}
}
protected DeploymentConfiguration createDeploymentConfiguration(
Properties initParameters) {
return new DefaultDeploymentConfiguration(getClass(), initParameters);
}
protected VaadinServletService createServletService(
DeploymentConfiguration deploymentConfiguration)
throws ServiceException {
VaadinServletService service = new VaadinServletService(this,
deploymentConfiguration);
service.init();
return service;
}
/**
* Receives standard HTTP requests from the public service method and
* dispatches them.
*
* @param request
* the object that contains the request the client made of the
* servlet.
* @param response
* the object that contains the response the servlet returns to
* the client.
* @throws ServletException
* if an input or output error occurs while the servlet is
* handling the TRACE request.
* @throws IOException
* if the request for the TRACE cannot be handled.
*/
@Override
protected void service(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// Handle context root request without trailing slash, see #9921
if (handleContextRootWithoutSlash(request, response)) {
return;
}
CurrentInstance.clearAll();
VaadinServletRequest vaadinRequest = createVaadinRequest(request);
VaadinServletResponse vaadinResponse = createVaadinResponse(response);
if (!ensureCookiesEnabled(vaadinRequest, vaadinResponse)) {
return;
}
if (isStaticResourceRequest(vaadinRequest)) {
// Define current servlet and service, but no request and response
getService().setCurrentInstances(null, null);
try {
serveStaticResources(vaadinRequest, vaadinResponse);
return;
} finally {
CurrentInstance.clearAll();
}
}
try {
getService().handleRequest(vaadinRequest, vaadinResponse);
} catch (ServiceException e) {
throw new ServletException(e);
}
}
/**
* Invoked for every request to this servlet to potentially send a redirect
* to avoid problems with requests to the context root with no trailing
* slash.
*
* @param request
* the processed request
* @param response
* the processed response
* @return <code>true</code> if a redirect has been sent and the request
* should not be processed further; <code>false</code> if the
* request should be processed as usual
* @throws IOException
* If an input or output exception occurs
*/
protected boolean handleContextRootWithoutSlash(HttpServletRequest request,
HttpServletResponse response) throws IOException {
// Query parameters like "?a=b" are handled by the servlet container but
// path parameter (e.g. ;jsessionid=) needs to be handled here
String location = request.getRequestURI();
String lastPathParameter = getLastPathParameter(location);
location = location.substring(0,
location.length() - lastPathParameter.length());
if ((request.getPathInfo() == null || "/".equals(request.getPathInfo()))
&& "".equals(request.getServletPath())
&& !location.endsWith("/")) {
/*
* Path info is for the root but request URI doesn't end with a
* slash -> redirect to the same URI but with an ending slash.
*/
location = location + "/" + lastPathParameter;
String queryString = request.getQueryString();
if (queryString != null) {
// Prevent HTTP Response splitting in case the server doesn't
queryString = queryString.replaceAll("[\\r\\n]", "");
location += '?' + queryString;
}
response.sendRedirect(location);
return true;
} else {
return false;
}
}
/**
* Finds any path parameter added to the last part of the uri. A path
* parameter is any string separated by ";" from the path and ends in / or
* at the end of the string.
* <p>
* For example the uri http://myhost.com/foo;a=1/bar;b=1 contains two path
* parameters, {@literal a=1} related to {@literal /foo} and {@literal b=1}
* related to /bar.
* <p>
* For http://myhost.com/foo;a=1/bar;b=1 this method will return ;b=1
*
* @since 7.2
* @param uri
* a URI
* @return the last path parameter of the uri including the semicolon or an
* empty string. Never null.
*/
protected static String getLastPathParameter(String uri) {
int lastPathStart = uri.lastIndexOf('/');
if (lastPathStart == -1) {
return "";
}
int semicolonPos = uri.indexOf(';', lastPathStart);
if (semicolonPos < 0) {
// No path parameter for the last part
return "";
} else {
// This includes the semicolon.
String semicolonString = uri.substring(semicolonPos);
return semicolonString;
}
}
private VaadinServletResponse createVaadinResponse(
HttpServletResponse response) {
return new VaadinServletResponse(response, getService());
}
/**
* Create a Vaadin request for a http servlet request. This method can be
* overridden if the Vaadin request should have special properties.
*
* @param request
* the original http servlet request
* @return a Vaadin request for the original request
*/
protected VaadinServletRequest createVaadinRequest(
HttpServletRequest request) {
return new VaadinServletRequest(request, getService());
}
/**
* Gets a the vaadin service for this servlet.
*
* @return the vaadin service
*/
protected VaadinServletService getService() {
return servletService;
}
/**
* Check that cookie support is enabled in the browser. Only checks UIDL
* requests.
*
* @param request
* The request from the browser
* @param response
* The response to which an error can be written
* @return false if cookies are disabled, true otherwise
* @throws IOException
*/
private boolean ensureCookiesEnabled(VaadinServletRequest request,
VaadinServletResponse response) throws IOException {
if (ServletPortletHelper.isUIDLRequest(request)) {
// In all other but the first UIDL request a cookie should be
// returned by the browser.
// This can be removed if cookieless mode (#3228) is supported
if (request.getRequestedSessionId() == null) {
// User has cookies disabled
SystemMessages systemMessages = getService().getSystemMessages(
ServletPortletHelper.findLocale(null, null, request),
request);
getService().writeStringResponse(response,
JsonConstants.JSON_CONTENT_TYPE,
VaadinService.createCriticalNotificationJSON(
systemMessages.getCookiesDisabledCaption(),
systemMessages.getCookiesDisabledMessage(),
null, systemMessages.getCookiesDisabledURL()));
return false;
}
}
return true;
}
/**
* Send a notification to client-side widgetset. Used to notify client of
* critical errors, session expiration and more. Server has no knowledge of
* what UI client refers to.
*
* @param request
* the HTTP request instance.
* @param response
* the HTTP response to write to.
* @param caption
* the notification caption
* @param message
* to notification body
* @param details
* a detail message to show in addition to the message. Currently
* shown directly below the message but could be hidden behind a
* details drop down in the future. Mainly used to give
* additional information not necessarily useful to the end user.
* @param url
* url to load when the message is dismissed. Null will reload
* the current page.
* @throws IOException
* if the writing failed due to input/output error.
*
* @deprecated As of 7.0. This method is retained only for backwards
* compatibility and for GAEVaadinServlet.
*/
@Deprecated
protected void criticalNotification(VaadinServletRequest request,
VaadinServletResponse response, String caption, String message,
String details, String url) throws IOException {
if (ServletPortletHelper.isUIDLRequest(request)) {
String output = VaadinService.createCriticalNotificationJSON(
caption, message, details, url);
getService().writeStringResponse(response,
JsonConstants.JSON_CONTENT_TYPE, output);
} else {
// Create an HTML reponse with the error
String output = "";
if (url != null) {
output += "<a href=\"" + url + "\">";
}
if (caption != null) {
output += "<b>" + caption + "</b><br/>";
}
if (message != null) {
output += message;
output += "<br/><br/>";
}
if (details != null) {
output += details;
output += "<br/><br/>";
}
if (url != null) {
output += "</a>";
}
getService().writeStringResponse(response,
ApplicationConstants.CONTENT_TYPE_TEXT_HTML_UTF_8, output);
}
}
/**
* Writes the response in {@code output} using the contentType given in
* {@code contentType} to the provided {@link HttpServletResponse}
*
* @param response
* @param contentType
* @param output
* Output to write (UTF-8 encoded)
* @throws IOException
*/
private void writeResponse(HttpServletResponse response, String contentType,
String output) throws IOException {
response.setContentType(contentType);
final OutputStream out = response.getOutputStream();
try ( // Set the response type
PrintWriter outWriter = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(out, "UTF-8")))) {
outWriter.print(output);
outWriter.flush();
}
}
/**
* Gets resource path using different implementations. Required to
* supporting different servlet container implementations (application
* servers).
*
* @param servletContext
* @param path
* the resource path.
* @return the resource path.
*
* @deprecated As of 7.0. Will likely change or be removed in a future
* version
*/
@Deprecated
protected static String getResourcePath(ServletContext servletContext,
String path) {
String resultPath = null;
resultPath = servletContext.getRealPath(path);
if (resultPath != null) {
return resultPath;
} else {
try {
final URL url = servletContext.getResource(path);
resultPath = url.getFile();
} catch (final Exception e) {
// FIXME: Handle exception
getLogger().log(Level.INFO,
"Could not find resource path " + path, e);
}
}
return resultPath;
}
/**
* A helper method to strip away characters that might somehow be used for
* XSS attacks. Leaves at least alphanumeric characters intact. Also removes
* e.g. '(' and ')', so values should be safe in javascript too.
*
* @param themeName
* @return
*
* @deprecated As of 7.0. Will likely change or be removed in a future
* version
*/
@Deprecated
public static String stripSpecialChars(String themeName) {
StringBuilder sb = new StringBuilder();
char[] charArray = themeName.toCharArray();
for (char c : charArray) {
if (!CHAR_BLACKLIST.contains(c)) {
sb.append(c);
}
}
return sb.toString();
}
private static final Collection<Character> CHAR_BLACKLIST = new HashSet<>(
Arrays.asList(new Character[] { '&', '"', '\'', '<', '>', '(', ')',
';' }));
/**
* Mutex for preventing to scss compilations to take place simultaneously.
* This is a workaround needed as the scss compiler currently is not thread
* safe (#10292).
* <p>
* In addition, this is also used to protect the cached compilation results.
*/
private static final Object SCSS_MUTEX = new Object();
/**
* Global cache of scss compilation results. This map is protected from
* concurrent access by {@link #SCSS_MUTEX}.
*/
private final Map<String, ScssCacheEntry> scssCache = new HashMap<>();
/**
* Keeps track of whether a warning about not being able to persist cache
* files has already been printed. The flag is protected from concurrent
* access by {@link #SCSS_MUTEX}.
*/
private static boolean scssCompileWarWarningEmitted = false;
/**
* Returns the default theme. Must never return null.
*
* @return
*/
public static String getDefaultTheme() {
return DEFAULT_THEME_NAME;
}
/**
* Check if this is a request for a static resource and, if it is, serve the
* resource to the client.
*
* @param request
* @param response
* @return true if a file was served and the request has been handled, false
* otherwise.
* @throws IOException
* @throws ServletException
*/
private boolean serveStaticResources(HttpServletRequest request,
HttpServletResponse response) throws IOException, ServletException {
String filePath = getStaticFilePath(request);
if (filePath != null) {
serveStaticResourcesInVAADIN(filePath, request, response);
return true;
}
return false;
}
/**
* Serve resources from VAADIN directory.
*
* @param filename
* The filename to serve. Should always start with /VAADIN/.
* @param request
* @param response
* @throws IOException
* @throws ServletException
*/
private void serveStaticResourcesInVAADIN(String filename,
HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {
final ServletContext sc = getServletContext();
URL resourceUrl = findResourceURL(filename);
if (resourceUrl == null) {
// File not found, if this was a css request we still look for a
// scss file with the same name
if (serveOnTheFlyCompiledScss(filename, request, response, sc)) {
return;
} else {
// cannot serve requested file
getLogger().log(Level.INFO,
"Requested resource [{0}] not found from filesystem or through class loader."
+ " Add widgetset and/or theme JAR to your classpath or add files to WebContent/VAADIN folder.",
filename);
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
}
return;
}
// security check: do not permit navigation out of the VAADIN
// directory
if (!isAllowedVAADINResourceUrl(request, resourceUrl)) {
getLogger().log(Level.INFO,
"Requested resource [{0}] not accessible in the VAADIN directory or access to it is forbidden.",
filename);
response.setStatus(HttpServletResponse.SC_FORBIDDEN);
return;
}
String cacheControl = "public, max-age=0, must-revalidate";
int resourceCacheTime = getCacheTime(filename);
if (resourceCacheTime > 0) {
cacheControl = "max-age=" + String.valueOf(resourceCacheTime);
}
response.setHeader("Cache-Control", cacheControl);
response.setDateHeader("Expires",
System.currentTimeMillis() + resourceCacheTime * 1000);
// Find the modification timestamp
long lastModifiedTime = 0;
URLConnection connection = null;
try {
connection = resourceUrl.openConnection();
lastModifiedTime = connection.getLastModified();
// Remove milliseconds to avoid comparison problems (milliseconds
// are not returned by the browser in the "If-Modified-Since"
// header).
lastModifiedTime -= lastModifiedTime % 1000;
response.setDateHeader("Last-Modified", lastModifiedTime);
if (browserHasNewestVersion(request, lastModifiedTime)) {
response.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return;
}
} catch (Exception e) {
// Failed to find out last modified timestamp. Continue without it.
getLogger().log(Level.FINEST,
"Failed to find out last modified timestamp. Continuing without it.",
e);
} finally {
try {
// Explicitly close the input stream to prevent it
// from remaining hanging
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4257700
InputStream is = connection.getInputStream();
if (is != null) {
is.close();
}
} catch (FileNotFoundException e) {
// Not logging when the file does not exist.
} catch (IOException e) {
getLogger().log(Level.INFO,
"Error closing URLConnection input stream", e);
}
}
// Set type mime type if we can determine it based on the filename
final String mimetype = sc.getMimeType(filename);
if (mimetype != null) {
response.setContentType(mimetype);
}
writeStaticResourceResponse(request, response, resourceUrl);
}
/**
* Calculates the cache lifetime for the given filename in seconds. By
* default filenames containing ".nocache." return 0, filenames containing
* ".cache." return one year, all other return the value defined in the
* web.xml using resourceCacheTime (defaults to 1 hour).
*
* @param filename
* @return cache lifetime for the given filename in seconds
*/
protected int getCacheTime(String filename) {
/*
* GWT conventions:
*
* - files containing .nocache. will not be cached.
*
* - files containing .cache. will be cached for one year.
*
* https://developers.google.com/web-toolkit/doc/latest/
* DevGuideCompilingAndDebugging#perfect_caching
*/
if (filename.contains(".nocache.")) {
return 0;
}
if (filename.contains(".cache.")) {
return 60 * 60 * 24 * 365;
}
/*
* For all other files, the browser is allowed to cache for 1 hour
* without checking if the file has changed. This forces browsers to
* fetch a new version when the Vaadin version is updated. This will
* cause more requests to the servlet than without this but for high
* volume sites the static files should never be served through the
* servlet.
*/
return getService().getDeploymentConfiguration().getResourceCacheTime();
}
/**
* Writes the contents of the given resourceUrl in the response. Can be
* overridden to add/modify response headers and similar.
*
* @param request
* The request for the resource
* @param response
* The response
* @param resourceUrl
* The url to send
* @throws IOException
*/
protected void writeStaticResourceResponse(HttpServletRequest request,
HttpServletResponse response, URL resourceUrl) throws IOException {
URLConnection connection = null;
InputStream is = null;
String urlStr = resourceUrl.toExternalForm();
if (allowServePrecompressedResource(request, urlStr)) {
// try to serve a precompressed version if available
try {
connection = new URL(urlStr + ".gz").openConnection();
is = connection.getInputStream();
// set gzip headers
response.setHeader("Content-Encoding", "gzip");
} catch (IOException e) {
// NOP: will be still tried with non gzipped version
} catch (Exception e) {
getLogger().log(Level.FINE,
"Unexpected exception looking for gzipped version of resource "
+ urlStr,
e);
}
}
if (is == null) {
// precompressed resource not available, get non compressed
connection = resourceUrl.openConnection();
try {
is = connection.getInputStream();
} catch (FileNotFoundException e) {
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
return;
}
}
try {
int length = connection.getContentLength();
if (length >= 0) {
response.setContentLength(length);
}
} catch (Throwable e) {
// This can be ignored, content length header is not required.
// Need to close the input stream because of
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4257700 to
// prevent it from hanging, but that is done below.
}
try {
streamContent(response, is);
} finally {
is.close();
}
}
/**
* Returns whether this servlet should attempt to serve a precompressed
* version of the given static resource. If this method returns true, the
* suffix {@code .gz} is appended to the URL and the corresponding resource
* is served if it exists. It is assumed that the compression method used is
* gzip. If this method returns false or a compressed version is not found,
* the original URL is used.
*
* The base implementation of this method returns true if and only if the
* request indicates that the client accepts gzip compressed responses and
* the filename extension of the requested resource is .js, .css, or .html.
*
* @since 7.5.0
*
* @param request
* the request for the resource
* @param url
* the URL of the requested resource
* @return true if the servlet should attempt to serve a precompressed
* version of the resource, false otherwise
*/
protected boolean allowServePrecompressedResource(
HttpServletRequest request, String url) {
String accept = request.getHeader("Accept-Encoding");
return accept != null && accept.contains("gzip") && (url.endsWith(".js")
|| url.endsWith(".css") || url.endsWith(".html"));
}
private void streamContent(HttpServletResponse response, InputStream is)
throws IOException {
final OutputStream os = response.getOutputStream();
final byte buffer[] = new byte[DEFAULT_BUFFER_SIZE];
int bytes;
while ((bytes = is.read(buffer)) >= 0) {
os.write(buffer, 0, bytes);
}
}
/**
* Finds the given resource from the web content folder or using the class
* loader.
*
* @since 7.7
* @param filename
* The file to find, starting with a "/"
* @return The URL to the given file, or null if the file was not found
* @throws IOException
* if there was a problem while locating the file
*/
public URL findResourceURL(String filename) throws IOException {
URL resourceUrl = getServletContext().getResource(filename);
if (resourceUrl == null) {
// try if requested file is found from class loader
// strip leading "/" otherwise stream from JAR wont work
if (filename.startsWith("/")) {
filename = filename.substring(1);
}
resourceUrl = getService().getClassLoader().getResource(filename);
}
return resourceUrl;
}
private boolean serveOnTheFlyCompiledScss(String filename,
HttpServletRequest request, HttpServletResponse response,
ServletContext sc) throws IOException {
if (!filename.endsWith(".css")) {
return false;
}
String scssFilename = filename.substring(0, filename.length() - 4)
+ ".scss";
URL scssUrl = findResourceURL(scssFilename);
if (scssUrl == null) {
// Is a css request but no scss file was found
return false;
}
// security check: do not permit navigation out of the VAADIN
// directory
if (!isAllowedVAADINResourceUrl(request, scssUrl)) {
getLogger().log(Level.INFO,
"Requested resource [{0}] not accessible in the VAADIN directory or access to it is forbidden.",
filename);
response.setStatus(HttpServletResponse.SC_FORBIDDEN);
// Handled, return true so no further processing is done
return true;
}
if (getService().getDeploymentConfiguration().isProductionMode()) {
// This is not meant for production mode.
getLogger().log(Level.INFO,
"Request for {0} not handled by sass compiler while in production mode",
filename);
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
// Handled, return true so no further processing is done
return true;
}
synchronized (SCSS_MUTEX) {
ScssCacheEntry cacheEntry = scssCache.get(scssFilename);
if (cacheEntry == null) {
try {
cacheEntry = loadPersistedScssCache(scssFilename, sc);
} catch (Exception e) {
getLogger().log(Level.WARNING,
"Could not read persisted scss cache", e);
}
}
if (cacheEntry == null || !cacheEntry.isStillValid()) {
cacheEntry = compileScssOnTheFly(filename, scssFilename, sc);
persistCacheEntry(cacheEntry);
}
scssCache.put(scssFilename, cacheEntry);
if (cacheEntry == null) {
// compilation did not produce any result, but logged a message
return false;
}
// This is for development mode only so instruct the browser to
// never cache it
response.setHeader("Cache-Control", "no-cache");
final String mimetype = getService().getMimeType(filename);
writeResponse(response, mimetype, cacheEntry.getCss());
return true;
}
}
private ScssCacheEntry loadPersistedScssCache(String scssFilename,
ServletContext sc) throws IOException {
String realFilename = sc.getRealPath(scssFilename);
File scssCacheFile = getScssCacheFile(new File(realFilename));
if (!scssCacheFile.exists()) {
return null;
}
String jsonString = readFile(scssCacheFile, StandardCharsets.UTF_8);
JsonObject entryJson = Json.parse(jsonString);
String cacheVersion = entryJson.getString("version");
if (!Version.getFullVersion().equals(cacheVersion)) {
// Compiled for some other Vaadin version, discard cache
scssCacheFile.delete();
return null;
}
return new ScssCacheEntry(entryJson);
}
private ScssCacheEntry compileScssOnTheFly(String filename,
String scssFilename, ServletContext sc) throws IOException {
String realFilename = sc.getRealPath(scssFilename);
ScssStylesheet scss = ScssStylesheet.get(realFilename);
if (scss == null) {
// Not a file in the file system (WebContent directory). Use the
// identifier directly (VAADIN/themes/.../styles.css) so
// ScssStylesheet will try using the class loader.
if (scssFilename.startsWith("/")) {
scssFilename = scssFilename.substring(1);
}
scss = ScssStylesheet.get(scssFilename);
}
if (scss == null) {
getLogger().log(Level.WARNING,
"Scss file {0} exists but ScssStylesheet was not able to find it",
scssFilename);
return null;
}
try {
getLogger().log(Level.FINE, "Compiling {0} for request to {1}",
new Object[] { realFilename, filename });
scss.compile();
} catch (Exception e) {
getLogger().log(Level.WARNING, "Scss compilation failed", e);
return null;
}
return new ScssCacheEntry(realFilename, scss.printState(),
scss.getSourceUris());
}
/**
* Check whether a URL obtained from a classloader refers to a valid static
* resource in the directory VAADIN.
*
* Warning: Overriding of this method is not recommended, but is possible to
* support non-default classloaders or servers that may produce URLs
* different from the normal ones. The method prototype may change in the
* future. Care should be taken not to expose class files or other resources
* outside the VAADIN directory if the method is overridden.
*
* @param request
* @param resourceUrl
* @return
*
* @since 6.6.7
*
* @deprecated As of 7.0. Will likely change or be removed in a future
* version
*/
@Deprecated
protected boolean isAllowedVAADINResourceUrl(HttpServletRequest request,
URL resourceUrl) {
String resourcePath = resourceUrl.getPath();
if ("jar".equals(resourceUrl.getProtocol())) {
// This branch is used for accessing resources directly from the
// Vaadin JAR in development environments and in similar cases.
// Inside a JAR, a ".." would mean a real directory named ".." so
// using it in paths should just result in the file not being found.
// However, performing a check in case some servers or class loaders
// try to normalize the path by collapsing ".." before the class
// loader sees it.
if (!resourcePath.contains("!/VAADIN/")
&& !resourcePath.contains("!/META-INF/resources/VAADIN/")) {
getLogger().log(Level.INFO,
"Blocked attempt to access a JAR entry not starting with /VAADIN/: {0}",
resourceUrl);
return false;
}
getLogger().log(Level.FINE,
"Accepted access to a JAR entry using a class loader: {0}",
resourceUrl);
return true;
} else {
// Some servers such as GlassFish extract files from JARs (file:)
// and e.g. JBoss 5+ use protocols vsf: and vfsfile: .
// Check that the URL is in a VAADIN directory and does not contain
// "/../"
if (!resourcePath.contains("/VAADIN/")
|| resourcePath.contains("/../")) {
getLogger().log(Level.INFO,
"Blocked attempt to access file: {0}", resourceUrl);
return false;
}
getLogger().log(Level.FINE,
"Accepted access to a file using a class loader: {0}",
resourceUrl);
return true;
}
}
/**
* Checks if the browser has an up to date cached version of requested
* resource. Currently the check is performed using the "If-Modified-Since"
* header. Could be expanded if needed.
*
* @param request
* The HttpServletRequest from the browser.
* @param resourceLastModifiedTimestamp
* The timestamp when the resource was last modified. 0 if the
* last modification time is unknown.
* @return true if the If-Modified-Since header tells the cached version in
* the browser is up to date, false otherwise
*/
private boolean browserHasNewestVersion(HttpServletRequest request,
long resourceLastModifiedTimestamp) {
if (resourceLastModifiedTimestamp < 1) {
// We do not know when it was modified so the browser cannot have an
// up-to-date version
return false;
}
/*
* The browser can request the resource conditionally using an
* If-Modified-Since header. Check this against the last modification
* time.
*/
try {
// If-Modified-Since represents the timestamp of the version cached
// in the browser
long headerIfModifiedSince = request
.getDateHeader("If-Modified-Since");
if (headerIfModifiedSince >= resourceLastModifiedTimestamp) {
// Browser has this an up-to-date version of the resource
return true;
}
} catch (Exception e) {
// Failed to parse header. Fail silently - the browser does not have
// an up-to-date version in its cache.
}
return false;
}
/**
*
* @author Vaadin Ltd
* @since 7.0
*
* @deprecated As of 7.0. This is no longer used and only provided for
* backwards compatibility. Each {@link RequestHandler} can
* individually decide whether it wants to handle a request or
* not.
*/
@Deprecated
protected enum RequestType {
FILE_UPLOAD, BROWSER_DETAILS, UIDL, OTHER, STATIC_FILE, APP, PUBLISHED_FILE, HEARTBEAT;
}
/**
* @param request
* @return
*
* @deprecated As of 7.0. This is no longer used and only provided for
* backwards compatibility. Each {@link RequestHandler} can
* individually decide whether it wants to handle a request or
* not.
*/
@Deprecated
protected RequestType getRequestType(VaadinServletRequest request) {
if (ServletPortletHelper.isFileUploadRequest(request)) {
return RequestType.FILE_UPLOAD;
} else if (ServletPortletHelper.isPublishedFileRequest(request)) {
return RequestType.PUBLISHED_FILE;
} else if (ServletUIInitHandler.isUIInitRequest(request)) {
return RequestType.BROWSER_DETAILS;
} else if (ServletPortletHelper.isUIDLRequest(request)) {
return RequestType.UIDL;
} else if (isStaticResourceRequest(request)) {
return RequestType.STATIC_FILE;
} else if (ServletPortletHelper.isAppRequest(request)) {
return RequestType.APP;
} else if (ServletPortletHelper.isHeartbeatRequest(request)) {
return RequestType.HEARTBEAT;
}
return RequestType.OTHER;
}
protected boolean isStaticResourceRequest(HttpServletRequest request) {
return getStaticFilePath(request) != null;
}
/**
* Returns the relative path at which static files are served for a request
* (if any).
*
* @param request
* HTTP request
* @return relative servlet path or null if the request path does not
* contain "/VAADIN/" or the request has no path info
* @since 8.0
*/
protected String getStaticFilePath(HttpServletRequest request) {
String pathInfo = request.getPathInfo();
if (pathInfo == null) {
return null;
}
// Servlet mapped as /* serves at /VAADIN
// Servlet mapped as /foo/bar/* serves at /foo/bar/VAADIN
if (pathInfo.startsWith("/VAADIN/")) {
return pathInfo;
}
String servletPrefixedPath = request.getServletPath() + pathInfo;
// Servlet mapped as /VAADIN/*
if (servletPrefixedPath.startsWith("/VAADIN/")) {
return servletPrefixedPath;
}
return null;
}
/**
* Remove any heading or trailing "what" from the "string".
*
* @param string
* @param what
* @return
*/
static String removeHeadingOrTrailing(String string, String what) {
while (string.startsWith(what)) {
string = string.substring(1);
}
while (string.endsWith(what)) {
string = string.substring(0, string.length() - 1);
}
return string;
}
/**
* Gets the current application URL from request.
*
* @param request
* the HTTP request.
* @throws MalformedURLException
* if the application is denied access to the persistent data
* store represented by the given URL.
*
* @deprecated As of 7.0. Will likely change or be removed in a future
* version
*/
@Deprecated
protected URL getApplicationUrl(HttpServletRequest request)
throws MalformedURLException {
final URL reqURL = new URL((request.isSecure() ? "https://" : "http://")
+ request.getServerName()
+ (request.isSecure() && request.getServerPort() == 443
|| !request.isSecure() && request.getServerPort() == 80
? "" : ":" + request.getServerPort())
+ request.getRequestURI());
String servletPath = "";
if (request
.getAttribute("javax.servlet.include.servlet_path") != null) {
// this is an include request
servletPath = request
.getAttribute("javax.servlet.include.context_path")
.toString()
+ request
.getAttribute("javax.servlet.include.servlet_path");
} else {
servletPath = request.getContextPath() + request.getServletPath();
}
if (servletPath.length() == 0
|| servletPath.charAt(servletPath.length() - 1) != '/') {
servletPath += "/";
}
URL u = new URL(reqURL, servletPath);
return u;
}
/*
* (non-Javadoc)
*
* @see javax.servlet.GenericServlet#destroy()
*/
@Override
public void destroy() {
super.destroy();
getService().destroy();
}
private static void persistCacheEntry(ScssCacheEntry cacheEntry) {
String scssFileName = cacheEntry.getScssFileName();
if (scssFileName == null) {
if (!scssCompileWarWarningEmitted) {
getLogger().warning(
"Could not persist scss cache because no real file was found for the compiled scss file. "
+ "This might happen e.g. if serving the scss file directly from a .war file.");
scssCompileWarWarningEmitted = true;
}
return;
}
File scssFile = new File(scssFileName);
File cacheFile = getScssCacheFile(scssFile);
String cacheEntryJsonString = cacheEntry.asJson();
try {
writeFile(cacheEntryJsonString, cacheFile, StandardCharsets.UTF_8);
} catch (IOException e) {
getLogger().log(Level.WARNING,
"Error persisting scss cache " + cacheFile, e);
}
}
private static String readFile(File file, Charset charset)
throws IOException {
try (InputStream in = new FileInputStream(file)) {
// no point in reading files over 2GB to a String
byte[] b = new byte[(int) file.length()];
int len = b.length;
int total = 0;
while (total < len) {
int result = in.read(b, total, len - total);
if (result == -1) {
break;
}
total += result;
}
return new String(b, charset);
}
}
private static void writeFile(String content, File file, Charset charset)
throws IOException {
try (FileOutputStream fos = new FileOutputStream(file)) {
fos.write(content.getBytes(charset));
}
}
private static File getScssCacheFile(File scssFile) {
return new File(scssFile.getParentFile(),
scssFile.getName() + ".cache");
}
/**
* Escapes characters to html entities. An exception is made for some "safe
* characters" to keep the text somewhat readable.
*
* @param unsafe
* @return a safe string to be added inside an html tag
*
* @deprecated As of 7.0. Will likely change or be removed in a future
* version
*/
@Deprecated
public static final String safeEscapeForHtml(String unsafe) {
if (null == unsafe) {
return null;
}
StringBuilder safe = new StringBuilder();
char[] charArray = unsafe.toCharArray();
for (char c : charArray) {
if (isSafe(c)) {
safe.append(c);
} else {
safe.append("&#");
safe.append((int) c);
safe.append(";");
}
}
return safe.toString();
}
private static boolean isSafe(char c) {
return //
c > 47 && c < 58 || // alphanum
c > 64 && c < 91 || // A-Z
c > 96 && c < 123 // a-z
;
}
private static final Logger getLogger() {
return Logger.getLogger(VaadinServlet.class.getName());
}
}