ru.frostman.web.dispatch.Dispatcher Maven / Gradle / Ivy
/******************************************************************************
* WebJavin - Java Web Framework. *
* *
* Copyright (c) 2011 - Sergey "Frosman" Lukjanov, [email protected] *
* *
* 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 ru.frostman.web.dispatch;
import com.google.common.base.Objects;
import com.google.common.collect.Lists;
import org.apache.commons.io.IOUtils;
import ru.frostman.web.config.JavinConfig;
import ru.frostman.web.config.StaticResource;
import ru.frostman.web.controller.Controllers;
import ru.frostman.web.thr.JavinRuntimeException;
import ru.frostman.web.thr.NotFoundException;
import ru.frostman.web.util.Crypto;
import ru.frostman.web.util.HttpMethod;
import ru.frostman.web.util.MimeTypes;
import ru.frostman.web.util.Resources;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
* @author slukjanov aka Frostman
*/
public class Dispatcher {
private static final String HEADER_IF_NONE_MATCH = "If-None-Match";
private static final String HEADER_E_TAG = "ETag";
private static final String HEADER_IF_MODIFIED_SINCE = "If-Modified-Since";
private static final String HEADER_LAST_MODIFIED = "Last-Modified";
private static final String HEADER_EXPIRES = "Expires";
public static final long DEFAULT_EXPIRE_TIME = 604800000L; // 1 week
private final List actions;
public Dispatcher(List actions) {
this.actions = Lists.newLinkedList(actions);
}
public void dispatch(String requestUrl, HttpMethod requestMethod, HttpServletRequest request
, HttpServletResponse response) {
if (JavinConfig.get().getContext().equals(requestUrl)) {
requestUrl += "/";
}
if (dispatchStatic(requestUrl, requestMethod, request, response)) {
return;
}
ActionInvoker invoker = null;
if (invoker == null) {
for (ActionDefinition definition : actions) {
if (definition.matches(requestUrl, requestMethod)) {
invoker = definition.initInvoker(request, response);
break;
}
}
}
if (invoker == null) {
sendNotFound(response, request.getRequestURI());
} else {
try {
invoker.invoke();
} catch (NotFoundException e) {
sendNotFound(response, e.getMessage());
}
}
}
private boolean dispatchStatic(String url, HttpMethod requestMethod, HttpServletRequest request,
HttpServletResponse response) {
if (url.contains("..")) {
// for security reasons '..' in path isn't supported
return false;
}
if (requestMethod.equals(HttpMethod.GET))
//todo impl caching in memory, think about regexp in statics
//todo compile expressions on AppClasses#update
for (Map.Entry entry : JavinConfig.get().getStatics().entrySet()) {
String fullUrl = Controllers.url(entry.getKey());
if (url.startsWith(fullUrl)) {
StaticResource staticResource = entry.getValue();
String resourceName = staticResource.getTarget() + "/" + url.substring(fullUrl.length() - 1);
try {
File resourceFile = Resources.getResourceAsFile(resourceName);
if (resourceFile == null || !resourceFile.isFile()) {
continue;
}
long length = resourceFile.length();
long lastModified = resourceFile.lastModified();
String eTag = Crypto.fastHash(resourceFile.getName() + "_" + length + "_" + lastModified);
if (ensureNotModified(request, response, lastModified, eTag)) {
return true;
}
String contentType = MimeTypes.getContentType(resourceFile.getName());
response.setContentType(contentType);
response.setCharacterEncoding(contentType.startsWith("text") ? "utf-8" : null);
// set headers for client side caching
response.setHeader(HEADER_E_TAG, eTag);
response.setDateHeader(HEADER_LAST_MODIFIED, lastModified);
response.setDateHeader(HEADER_EXPIRES, System.currentTimeMillis() + staticResource.getExpire());
FileInputStream resourceStream = new FileInputStream(resourceFile);
IOUtils.copy(resourceStream, response.getOutputStream());
} catch (FileNotFoundException e) {
continue;
} catch (IOException e) {
throw new JavinRuntimeException("Exception while sending static resourceName", e);
}
return true;
}
}
return false;
}
/**
* Check headers for client side caching
*
* @param request object
* @param response object
* @param lastModified time
* @param eTag smth like uid
*
* @return true iff request processed
*/
private boolean ensureNotModified(HttpServletRequest request, HttpServletResponse response, long lastModified, String eTag) {
// If-None-Match header should contain "*" or ETag. If so, then return 304.
String ifNoneMatch = request.getHeader(HEADER_IF_NONE_MATCH);
if (ifNoneMatch != null && (Objects.equal(ifNoneMatch, eTag) || Objects.equal(ifNoneMatch, "*"))) {
sendNotModified(response, eTag);
return true;
}
// If-Modified-Since header should be greater than LastModified. If so, then return 304.
// This header is ignored if any If-None-Match header is specified.
long ifModifiedSince = request.getDateHeader(HEADER_IF_MODIFIED_SINCE);
if (ifNoneMatch == null && ifModifiedSince != -1 && ifModifiedSince + 1000 > lastModified) {
sendNotModified(response, eTag);
return true;
}
return false;
}
private void sendNotFound(HttpServletResponse response, String msg) {
try {
response.sendError(HttpServletResponse.SC_NOT_FOUND, msg != null ? msg : "");
} catch (IOException e) {
throw new JavinRuntimeException("Exception while sending 404: Not found", e);
}
}
private void sendNotModified(HttpServletResponse response, String eTag) {
try {
response.setHeader(HEADER_E_TAG, eTag); // Required in 304.
response.sendError(HttpServletResponse.SC_NOT_MODIFIED);
} catch (IOException e) {
throw new JavinRuntimeException("Exception while sending 304: Not modified", e);
}
}
}
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