/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.catalina.webresources;
import java.io.InputStream;
import java.security.MessageDigest;
import org.apache.catalina.WebResource;
import org.apache.catalina.WebResourceRoot;
import org.apache.juli.logging.Log;
import org.apache.tomcat.util.buf.HexUtils;
import org.apache.tomcat.util.http.FastHttpDateFormat;
import org.apache.tomcat.util.res.StringManager;
import org.apache.tomcat.util.security.ConcurrentMessageDigest;
public abstract class AbstractResource implements WebResource {
protected static final StringManager sm = StringManager.getManager(AbstractResource.class);
private final WebResourceRoot root;
private final String webAppPath;
private String mimeType = null;
private volatile String weakETag;
private volatile String strongETag;
protected AbstractResource(WebResourceRoot root, String webAppPath) {
this.root = root;
this.webAppPath = webAppPath;
}
@Override
public final WebResourceRoot getWebResourceRoot() {
return root;
}
@Override
public final String getWebappPath() {
return webAppPath;
}
@Override
public final String getLastModifiedHttp() {
return FastHttpDateFormat.formatDate(getLastModified());
}
@Override
public final String getETag() {
if (weakETag == null) {
synchronized (this) {
if (weakETag == null) {
long contentLength = getContentLength();
long lastModified = getLastModified();
if ((contentLength >= 0) || (lastModified >= 0)) {
weakETag = "W/\"" + contentLength + "-" + lastModified + "\"";
}
}
}
}
return weakETag;
}
@Override
public final String getStrongETag() {
if (strongETag == null) {
synchronized (this) {
if (strongETag == null) {
long contentLength = getContentLength();
long lastModified = getLastModified();
if (contentLength > 0 && lastModified > 0) {
if (contentLength <= 16 * 1024) {
byte[] buf = getContent();
if (buf != null) {
buf = ConcurrentMessageDigest.digestSHA256(buf);
strongETag = "\"" + HexUtils.toHexString(buf) + "\"";
} else {
strongETag = getETag();
}
} else {
byte[] buf = new byte[4096];
try (InputStream is = getInputStream()) {
MessageDigest digest = MessageDigest.getInstance("SHA-256");
while (true) {
int n = is.read(buf);
if (n <= 0) {
break;
}
digest.update(buf, 0, n);
}
strongETag = "\"" + HexUtils.toHexString(digest.digest()) + "\"";
} catch (Exception e) {
strongETag = getETag();
}
}
} else {
strongETag = getETag();
}
}
}
}
return strongETag;
}
@Override
public final void setMimeType(String mimeType) {
this.mimeType = mimeType;
}
@Override
public final String getMimeType() {
if (mimeType == null) {
String name = getName();
int extensionStart = name.lastIndexOf('.');
if (extensionStart > -1) {
String extension = name.substring(extensionStart + 1);
mimeType = root.getContext().findMimeMapping(extension);
}
}
return mimeType;
}
@Override
public final InputStream getInputStream() {
InputStream is = doGetInputStream();
if (is == null || !root.getTrackLockedFiles()) {
return is;
}
return new TrackedInputStream(root, getName(), is);
}
protected abstract InputStream doGetInputStream();
protected abstract Log getLog();
}