net.sf.ehcache.constructs.web.PageInfo Maven / Gradle / Ivy
/**
* Copyright 2003-2009 Terracotta, Inc.
*
* 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 net.sf.ehcache.constructs.web;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* A Serializable representation of a {@link HttpServletResponse}.
*
* @author Adam Murdoch
* @author Greg Luck
* @version $Id: PageInfo.java 744 2008-08-16 20:10:49Z gregluck $
*/
public class PageInfo implements Serializable {
private static final Logger LOG = LoggerFactory.getLogger(PageInfo.class);
private static final int FOUR_KB = 4196;
private static final int GZIP_MAGIC_NUMBER_BYTE_1 = 31;
private static final int GZIP_MAGIC_NUMBER_BYTE_2 = -117;
private static final long ONE_YEAR_IN_SECONDS = 60 * 60 * 24 * 365;
private final ArrayList responseHeaders = new ArrayList();
private final ArrayList serializableCookies = new ArrayList();
private String contentType;
private byte[] gzippedBody;
private byte[] ungzippedBody;
private int statusCode;
private boolean storeGzipped;
private Date created;
private long timeToLiveSeconds;
/**
* Creates a PageInfo object representing the "page".
*
*
* @param statusCode
* @param contentType
* @param headers
* @param cookies
* @param body
* @param storeGzipped set this to false for images and page fragments which should never
* @param timeToLiveSeconds the time to Live in seconds. 0 means maximum, which is one year per RFC2616.
* @throws AlreadyGzippedException
*/
public PageInfo(final int statusCode, final String contentType, final Collection headers, final Collection cookies,
final byte[] body, boolean storeGzipped, long timeToLiveSeconds) throws AlreadyGzippedException {
if (headers != null) {
this.responseHeaders.addAll(headers);
}
setTimeToLiveWithCheckForNeverExpires(timeToLiveSeconds);
created = new Date();
this.responseHeaders.remove("Content-Encoding");
this.contentType = contentType;
this.storeGzipped = storeGzipped;
this.statusCode = statusCode;
this.timeToLiveSeconds = timeToLiveSeconds;
//bug 2630970
//extractCookies(cookies);
try {
if (storeGzipped) {
//gunzip on demand
ungzippedBody = null;
if (isBodyParameterGzipped()) {
gzippedBody = body;
} else {
gzippedBody = gzip(body);
}
} else {
if (isBodyParameterGzipped()) {
throw new IllegalArgumentException("Non gzip content has been gzipped.");
} else {
ungzippedBody = body;
}
}
} catch (IOException e) {
LOG.error("Error ungzipping gzipped body", e);
}
}
/**
* See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
* To mark a response as "never expires," an origin server sends an Expires date approximately one year
* from the time the response is sent. HTTP/1.1 servers SHOULD NOT send Expires dates more than one year
* in the future.
* @param timeToLiveSeconds accepts 0, which means eternal. If the time is 0 or > one year, it is set to one
* year in accordance with the RFC.
*
* Note: PageInfo does not hold a reference to the ehcache Element and therefore does not know what the
* Element ttl is. It would normally make most sense to set the TTL to the same as the element expiry.
*/
protected void setTimeToLiveWithCheckForNeverExpires(long timeToLiveSeconds) {
//0 means eternal
if (timeToLiveSeconds == 0 || timeToLiveSeconds > ONE_YEAR_IN_SECONDS) {
this.timeToLiveSeconds = ONE_YEAR_IN_SECONDS;
} else {
this.timeToLiveSeconds = timeToLiveSeconds;
}
}
private void extractCookies(Collection cookies) {
if (cookies != null) {
for (Iterator iterator = cookies.iterator(); iterator.hasNext();) {
final Cookie cookie = (Cookie) iterator.next();
serializableCookies.add(new SerializableCookie(cookie));
}
}
}
/**
* @param ungzipped the bytes to be gzipped
* @return gzipped bytes
*/
private byte[] gzip(byte[] ungzipped) throws IOException, AlreadyGzippedException {
if (isGzipped(ungzipped)) {
throw new AlreadyGzippedException("The byte[] is already gzipped. It should not be gzipped again.");
}
final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
final GZIPOutputStream gzipOutputStream = new GZIPOutputStream(bytes);
gzipOutputStream.write(ungzipped);
gzipOutputStream.close();
return bytes.toByteArray();
}
/**
* The response body will be assumed to be gzipped if the GZIP header has been set.
*
* @return true if the body is gzipped
*/
private boolean isBodyParameterGzipped() {
for (int i = 0; i < responseHeaders.size(); i++) {
String[] keyValuePair = (String[]) responseHeaders.get(i);
if (keyValuePair[1].equals("gzip")) {
return true;
}
}
return false;
}
/**
* Checks the first two bytes of the candidate byte array for the magic number 0x677a.
* This magic number was obtained from /usr/share/file/magic. The line for gzip is:
*
*
* >>14 beshort 0x677a (gzipped)
*
*
* @param candidate the byte array to check
* @return true if gzipped, false if null, less than two bytes or not gzipped
*/
public static boolean isGzipped(byte[] candidate) {
if (candidate == null || candidate.length < 2) {
return false;
} else {
return (candidate[0] == GZIP_MAGIC_NUMBER_BYTE_1 && candidate[1] == GZIP_MAGIC_NUMBER_BYTE_2);
}
}
/**
* @return the content type of the response.
*/
public String getContentType() {
return contentType;
}
/**
* @return the gzipped version of the body if the content is storeGzipped, otherwise null
*/
public byte[] getGzippedBody() {
if (storeGzipped) {
return gzippedBody;
} else {
return null;
}
}
/**
* Returns the headers of the response.
*/
public List getResponseHeaders() {
return responseHeaders;
}
/**
* Returns the cookies of the response.
*/
public List getSerializableCookies() {
return serializableCookies;
}
/**
* Returns the status code of the response.
*/
public int getStatusCode() {
return statusCode;
}
/**
* @return the ungzipped version of the body. This gunzipped on demand when storedGzipped, otherwise
* the ungzipped body is returned.
*/
public byte[] getUngzippedBody() throws IOException {
if (storeGzipped) {
return ungzip(gzippedBody);
} else {
return ungzippedBody;
}
}
/**
* A highly performant ungzip implementation. Do not refactor this without taking new timings.
* See ElementTest in ehcache for timings
*
* @param gzipped the gzipped content
* @return an ungzipped byte[]
* @throws java.io.IOException
*/
private byte[] ungzip(final byte[] gzipped) throws IOException {
final GZIPInputStream inputStream = new GZIPInputStream(new ByteArrayInputStream(gzipped));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(gzipped.length);
final byte[] buffer = new byte[FOUR_KB];
int bytesRead = 0;
while (bytesRead != -1) {
bytesRead = inputStream.read(buffer, 0, FOUR_KB);
if (bytesRead != -1) {
byteArrayOutputStream.write(buffer, 0, bytesRead);
}
}
byte[] ungzipped = byteArrayOutputStream.toByteArray();
inputStream.close();
byteArrayOutputStream.close();
return ungzipped;
}
/**
* @return true if there is a non null gzipped body
*/
public boolean hasGzippedBody() {
return (gzippedBody != null);
}
/**
* @return true if there is a non null ungzipped body
*/
public boolean hasUngzippedBody() {
return (ungzippedBody != null);
}
/**
* Returns true if the response is Ok.
*
* @return true if the response code is 200.
*/
public boolean isOk() {
return (statusCode == HttpServletResponse.SC_OK);
}
/**
* The Date this PageInfo object was created
*/
public Date getCreated() {
return created;
}
/**
* The time to live in seconds.
*
* @return the time to live, or 0 if the wrapping element is eternal
*/
public long getTimeToLiveSeconds() {
return timeToLiveSeconds;
}
}