AbstractAccessLogValve.java
/*
* 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.valves;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.net.InetAddress;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.TimeZone;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpSession;
import org.apache.catalina.AccessLog;
import org.apache.catalina.Globals;
import org.apache.catalina.Session;
import org.apache.catalina.connector.ClientAbortException;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.util.TLSUtil;
import org.apache.coyote.ActionCode;
import org.apache.coyote.RequestInfo;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.ExceptionUtils;
import org.apache.tomcat.util.buf.HexUtils;
import org.apache.tomcat.util.collections.SynchronizedStack;
import org.apache.tomcat.util.net.IPv6Utils;
/**
* <p>
* Abstract implementation of the <b>Valve</b> interface that generates a web server access log with the detailed line
* contents matching a configurable pattern. The syntax of the available patterns is similar to that supported by the
* <a href="https://httpd.apache.org/">Apache HTTP Server</a> <code>mod_log_config</code> module.
* </p>
* <p>
* Patterns for the logged message may include constant text or any of the following replacement strings, for which the
* corresponding information from the specified Response is substituted:
* </p>
* <ul>
* <li><b><code>%a</code></b> - Remote IP address
* <li><b><code>%A</code></b> - Local IP address
* <li><b><code>%b</code></b> - Bytes sent, excluding HTTP headers, or '-' if no bytes were sent
* <li><b><code>%B</code></b> - Bytes sent, excluding HTTP headers
* <li><b><code>%h</code></b> - Remote host name (or IP address if <code>enableLookups</code> for the connector is
* false)
* <li><b><code>%H</code></b> - Request protocol
* <li><b><code>%l</code></b> - Remote logical username from identd (always returns '-')
* <li><b><code>%m</code></b> - Request method
* <li><b><code>%p</code></b> - Local port
* <li><b><code>%q</code></b> - Query string (prepended with a '?' if it exists, otherwise an empty string
* <li><b><code>%r</code></b> - First line of the request
* <li><b><code>%s</code></b> - HTTP status code of the response
* <li><b><code>%S</code></b> - User session ID
* <li><b><code>%t</code></b> - Date and time, in Common Log Format format
* <li><b><code>%u</code></b> - Remote user that was authenticated
* <li><b><code>%U</code></b> - Requested URL path
* <li><b><code>%v</code></b> - Local server name
* <li><b><code>%D</code></b> - Time taken to process the request, in microseconds
* <li><b><code>%T</code></b> - Time taken to process the request, in seconds
* <li><b><code>%F</code></b> - Time taken to commit the response, in milliseconds
* <li><b><code>%I</code></b> - current Request thread name (can compare later with stacktraces)
* <li><b><code>%X</code></b> - Connection status when response is completed:
* <ul>
* <li><code>X</code> = Connection aborted before the response completed.</li>
* <li><code>+</code> = Connection may be kept alive after the response is sent.</li>
* <li><code>-</code> = Connection will be closed after the response is sent.</li>
* </ul>
* </ul>
* <p>
* In addition, the caller can specify one of the following aliases for commonly utilized patterns:
* </p>
* <ul>
* <li><b>common</b> - <code>%h %l %u %t "%r" %s %b</code>
* <li><b>combined</b> - <code>%h %l %u %t "%r" %s %b "%{Referer}i" "%{User-Agent}i"</code>
* </ul>
* <p>
* There is also support to write information from the cookie, incoming header, the Session or something else in the
* ServletRequest.<br>
* It is modeled after the <a href="https://httpd.apache.org/">Apache HTTP Server</a> log configuration syntax:
* </p>
* <ul>
* <li><code>%{xxx}i</code> for incoming headers
* <li><code>%{xxx}o</code> for outgoing response headers
* <li><code>%{xxx}c</code> for a specific cookie
* <li><code>%{xxx}r</code> xxx is an attribute in the ServletRequest
* <li><code>%{xxx}s</code> xxx is an attribute in the HttpSession
* <li><code>%{xxx}t</code> xxx is an enhanced SimpleDateFormat pattern (see Configuration Reference document for
* details on supported time patterns)
* <li><code>%{xxx}T</code> xxx is the unit for the time taken to process the request (see Configuration Reference
* document for details on supported units)
* </ul>
* <p>
* Conditional logging is also supported. This can be done with the <code>conditionUnless</code> and
* <code>conditionIf</code> properties. If the value returned from ServletRequest.getAttribute(conditionUnless) yields a
* non-null value, the logging will be skipped. If the value returned from ServletRequest.getAttribute(conditionIf)
* yields the null value, the logging will be skipped. The <code>condition</code> attribute is synonym for
* <code>conditionUnless</code> and is provided for backwards compatibility.
* </p>
* <p>
* For extended attributes coming from a getAttribute() call, it is you responsibility to ensure there are no newline or
* control characters.
* </p>
*
* @author Craig R. McClanahan
* @author Jason Brittain
* @author Remy Maucherat
* @author Takayuki Kaneko
* @author Peter Rossbach
*/
public abstract class AbstractAccessLogValve extends ValveBase implements AccessLog {
private static final Log log = LogFactory.getLog(AbstractAccessLogValve.class);
/**
* The list of our time format types.
*/
private enum FormatType {
CLF,
SEC,
MSEC,
MSEC_FRAC,
SDF
}
/**
* The list of our port types.
*/
private enum PortType {
LOCAL,
REMOTE
}
/**
* The list of our ip address types.
*/
private enum RemoteAddressType {
REMOTE,
PEER
}
// ------------------------------------------------------ Constructor
public AbstractAccessLogValve() {
super(true);
}
// ----------------------------------------------------- Instance Variables
/**
* enabled this component
*/
protected boolean enabled = true;
/**
* Use IPv6 canonical representation format as defined by RFC 5952.
*/
private boolean ipv6Canonical = false;
/**
* The pattern used to format our access log lines.
*/
protected String pattern = null;
/**
* The size of our global date format cache
*/
private static final int globalCacheSize = 300;
/**
* The size of our thread local date format cache
*/
private static final int localCacheSize = 60;
/**
* <p>
* Cache structure for formatted timestamps based on seconds.
* </p>
* <p>
* The cache consists of entries for a consecutive range of seconds. The length of the range is configurable. It is
* implemented based on a cyclic buffer. New entries shift the range.
* </p>
* <p>
* There is one cache for the CLF format (the access log standard format) and a HashMap of caches for additional
* formats used by SimpleDateFormat.
* </p>
* <p>
* Although the cache supports specifying a locale when retrieving a formatted timestamp, each format will always
* use the locale given when the format was first used. New locales can only be used for new formats. The CLF format
* will always be formatted using the locale <code>en_US</code>.
* </p>
* <p>
* The cache is not threadsafe. It can be used without synchronization via thread local instances, or with
* synchronization as a global cache.
* </p>
* <p>
* The cache can be created with a parent cache to build a cache hierarchy. Access to the parent cache is
* threadsafe.
* </p>
* <p>
* This class uses a small thread local first level cache and a bigger synchronized global second level cache.
* </p>
*/
protected static class DateFormatCache {
protected class Cache {
/* CLF log format */
private static final String cLFFormat = "dd/MMM/yyyy:HH:mm:ss Z";
/* Second used to retrieve CLF format in most recent invocation */
private long previousSeconds = Long.MIN_VALUE;
/* Value of CLF format retrieved in most recent invocation */
private String previousFormat = "";
/* First second contained in cache */
private long first = Long.MIN_VALUE;
/* Last second contained in cache */
private long last = Long.MIN_VALUE;
/* Index of "first" in the cyclic cache */
private int offset = 0;
/* Helper object to be able to call SimpleDateFormat.format(). */
private final Date currentDate = new Date();
protected final String cache[];
private SimpleDateFormat formatter;
private boolean isCLF = false;
private Cache parent = null;
private Cache(Cache parent) {
this(null, parent);
}
private Cache(String format, Cache parent) {
this(format, null, parent);
}
private Cache(String format, Locale loc, Cache parent) {
cache = new String[cacheSize];
for (int i = 0; i < cacheSize; i++) {
cache[i] = null;
}
if (loc == null) {
loc = cacheDefaultLocale;
}
if (format == null) {
isCLF = true;
format = cLFFormat;
formatter = new SimpleDateFormat(format, Locale.US);
} else {
formatter = new SimpleDateFormat(format, loc);
}
formatter.setTimeZone(TimeZone.getDefault());
this.parent = parent;
}
private String getFormatInternal(long time) {
long seconds = time / 1000;
/*
* First step: if we have seen this timestamp during the previous call, and we need CLF, return the
* previous value.
*/
if (seconds == previousSeconds) {
return previousFormat;
}
/* Second step: Try to locate in cache */
previousSeconds = seconds;
int index = (offset + (int) (seconds - first)) % cacheSize;
if (index < 0) {
index += cacheSize;
}
if (seconds >= first && seconds <= last) {
if (cache[index] != null) {
/* Found, so remember for next call and return. */
previousFormat = cache[index];
return previousFormat;
}
/* Third step: not found in cache, adjust cache and add item */
} else if (seconds >= last + cacheSize || seconds <= first - cacheSize) {
first = seconds;
last = first + cacheSize - 1;
index = 0;
offset = 0;
for (int i = 1; i < cacheSize; i++) {
cache[i] = null;
}
} else if (seconds > last) {
for (int i = 1; i < seconds - last; i++) {
cache[(index + cacheSize - i) % cacheSize] = null;
}
first = seconds - (cacheSize - 1);
last = seconds;
offset = (index + 1) % cacheSize;
} else if (seconds < first) {
for (int i = 1; i < first - seconds; i++) {
cache[(index + i) % cacheSize] = null;
}
first = seconds;
last = seconds + (cacheSize - 1);
offset = index;
}
/*
* Last step: format new timestamp either using parent cache or locally.
*/
if (parent != null) {
synchronized (parent) {
previousFormat = parent.getFormatInternal(time);
}
} else {
currentDate.setTime(time);
previousFormat = formatter.format(currentDate);
if (isCLF) {
StringBuilder current = new StringBuilder(32);
current.append('[');
current.append(previousFormat);
current.append(']');
previousFormat = current.toString();
}
}
cache[index] = previousFormat;
return previousFormat;
}
}
/* Number of cached entries */
private int cacheSize = 0;
private final Locale cacheDefaultLocale;
private final DateFormatCache parent;
protected final Cache cLFCache;
private final Map<String, Cache> formatCache = new HashMap<>();
protected DateFormatCache(int size, Locale loc, DateFormatCache parent) {
cacheSize = size;
cacheDefaultLocale = loc;
this.parent = parent;
Cache parentCache = null;
if (parent != null) {
synchronized (parent) {
parentCache = parent.getCache(null, null);
}
}
cLFCache = new Cache(parentCache);
}
private Cache getCache(String format, Locale loc) {
Cache cache;
if (format == null) {
cache = cLFCache;
} else {
cache = formatCache.get(format);
if (cache == null) {
Cache parentCache = null;
if (parent != null) {
synchronized (parent) {
parentCache = parent.getCache(format, loc);
}
}
cache = new Cache(format, loc, parentCache);
formatCache.put(format, cache);
}
}
return cache;
}
public String getFormat(long time) {
return cLFCache.getFormatInternal(time);
}
public String getFormat(String format, Locale loc, long time) {
return getCache(format, loc).getFormatInternal(time);
}
}
/**
* Global date format cache.
*/
private static final DateFormatCache globalDateCache = new DateFormatCache(globalCacheSize, Locale.getDefault(),
null);
/**
* Thread local date format cache.
*/
private static final ThreadLocal<DateFormatCache> localDateCache = ThreadLocal
.withInitial(() -> new DateFormatCache(localCacheSize, Locale.getDefault(), globalDateCache));
/**
* The system time when we last updated the Date that this valve uses for log lines.
*/
private static final ThreadLocal<Date> localDate = ThreadLocal.withInitial(Date::new);
/**
* Are we doing conditional logging. default null. It is the value of <code>conditionUnless</code> property.
*/
protected String condition = null;
/**
* Are we doing conditional logging. default null. It is the value of <code>conditionIf</code> property.
*/
protected String conditionIf = null;
/**
* Name of locale used to format timestamps in log entries and in log file name suffix.
*/
protected String localeName = Locale.getDefault().toString();
/**
* Locale used to format timestamps in log entries and in log file name suffix.
*/
protected Locale locale = Locale.getDefault();
/**
* Array of AccessLogElement, they will be used to make log message.
*/
protected AccessLogElement[] logElements = null;
/**
* Array of elements where the value needs to be cached at the start of the request.
*/
protected CachedElement[] cachedElements = null;
/**
* Should this valve use request attributes for IP address, hostname, protocol and port used for the request.
* Default is <code>false</code>.
*
* @see #setRequestAttributesEnabled(boolean)
*/
protected boolean requestAttributesEnabled = false;
/**
* Buffer pool used for log message generation. Pool used to reduce garbage generation.
*/
private SynchronizedStack<CharArrayWriter> charArrayWriters = new SynchronizedStack<>();
/**
* Log message buffers are usually recycled and re-used. To prevent excessive memory usage, if a buffer grows beyond
* this size it will be discarded. The default is 256 characters. This should be set to larger than the typical
* access log message size.
*/
private int maxLogMessageBufferSize = 256;
/**
* Does the configured log pattern include a known TLS attribute?
*/
private boolean tlsAttributeRequired = false;
// ------------------------------------------------------------- Properties
public int getMaxLogMessageBufferSize() {
return maxLogMessageBufferSize;
}
public void setMaxLogMessageBufferSize(int maxLogMessageBufferSize) {
this.maxLogMessageBufferSize = maxLogMessageBufferSize;
}
public boolean getIpv6Canonical() {
return ipv6Canonical;
}
public void setIpv6Canonical(boolean ipv6Canonical) {
this.ipv6Canonical = ipv6Canonical;
}
/**
* {@inheritDoc} Default is <code>false</code>.
*/
@Override
public void setRequestAttributesEnabled(boolean requestAttributesEnabled) {
this.requestAttributesEnabled = requestAttributesEnabled;
}
@Override
public boolean getRequestAttributesEnabled() {
return requestAttributesEnabled;
}
/**
* @return the enabled flag.
*/
public boolean getEnabled() {
return enabled;
}
/**
* @param enabled The enabled to set.
*/
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
/**
* @return the format pattern.
*/
public String getPattern() {
return this.pattern;
}
/**
* Set the format pattern, first translating any recognized alias.
*
* @param pattern The new pattern
*/
public void setPattern(String pattern) {
if (pattern == null) {
this.pattern = "";
} else if (pattern.equals(Constants.AccessLog.COMMON_ALIAS)) {
this.pattern = Constants.AccessLog.COMMON_PATTERN;
} else if (pattern.equals(Constants.AccessLog.COMBINED_ALIAS)) {
this.pattern = Constants.AccessLog.COMBINED_PATTERN;
} else {
this.pattern = pattern;
}
logElements = createLogElements();
if (logElements != null) {
cachedElements = createCachedElements(logElements);
}
}
/**
* Return whether the attribute name to look for when performing conditional logging. If null, every request is
* logged.
*
* @return the attribute name
*/
public String getCondition() {
return condition;
}
/**
* Set the ServletRequest.attribute to look for to perform conditional logging. Set to null to log everything.
*
* @param condition Set to null to log everything
*/
public void setCondition(String condition) {
this.condition = condition;
}
/**
* Return whether the attribute name to look for when performing conditional logging. If null, every request is
* logged.
*
* @return the attribute name
*/
public String getConditionUnless() {
return getCondition();
}
/**
* Set the ServletRequest.attribute to look for to perform conditional logging. Set to null to log everything.
*
* @param condition Set to null to log everything
*/
public void setConditionUnless(String condition) {
setCondition(condition);
}
/**
* Return whether the attribute name to look for when performing conditional logging. If null, every request is
* logged.
*
* @return the attribute name
*/
public String getConditionIf() {
return conditionIf;
}
/**
* Set the ServletRequest.attribute to look for to perform conditional logging. Set to null to log everything.
*
* @param condition Set to null to log everything
*/
public void setConditionIf(String condition) {
this.conditionIf = condition;
}
/**
* Return the locale used to format timestamps in log entries and in log file name suffix.
*
* @return the locale
*/
public String getLocale() {
return localeName;
}
/**
* Set the locale used to format timestamps in log entries and in log file name suffix. Changing the locale is only
* supported as long as the AccessLogValve has not logged anything. Changing the locale later can lead to
* inconsistent formatting.
*
* @param localeName The locale to use.
*/
public void setLocale(String localeName) {
this.localeName = localeName;
locale = findLocale(localeName, locale);
}
// --------------------------------------------------------- Public Methods
/**
* Log a message summarizing the specified request and response, according to the format specified by the
* <code>pattern</code> property.
*
* @param request Request being processed
* @param response Response being processed
*
* @exception IOException if an input/output error has occurred
* @exception ServletException if a servlet error has occurred
*/
@Override
public void invoke(Request request, Response response) throws IOException, ServletException {
if (tlsAttributeRequired) {
// The log pattern uses TLS attributes. Ensure these are populated
// before the request is processed because with NIO2 it is possible
// for the connection to be closed (and the TLS info lost) before
// the access log requests the TLS info. Requesting it now causes it
// to be cached in the request.
request.getAttribute(Globals.CERTIFICATES_ATTR);
}
if (cachedElements != null) {
for (CachedElement element : cachedElements) {
element.cache(request);
}
}
getNext().invoke(request, response);
}
@Override
public void log(Request request, Response response, long time) {
if (!getState().isAvailable() || !getEnabled() || logElements == null ||
condition != null && null != request.getRequest().getAttribute(condition) ||
conditionIf != null && null == request.getRequest().getAttribute(conditionIf)) {
return;
}
// Date for access log should be the beginning of the request
Date date = getDate(request.getCoyoteRequest().getStartTime());
CharArrayWriter result = charArrayWriters.pop();
if (result == null) {
result = new CharArrayWriter(128);
}
for (AccessLogElement logElement : logElements) {
logElement.addElement(result, date, request, response, time);
}
log(result);
if (result.size() <= maxLogMessageBufferSize) {
result.reset();
charArrayWriters.push(result);
}
}
// -------------------------------------------------------- Protected Methods
/**
* Log the specified message.
*
* @param message Message to be logged. This object will be recycled by the calling method.
*/
protected abstract void log(CharArrayWriter message);
// -------------------------------------------------------- Private Methods
/**
* This method returns a Date object that is accurate to within one second. If a thread calls this method to get a
* Date and it's been less than 1 second since a new Date was created, this method simply gives out the same Date
* again so that the system doesn't spend time creating Date objects unnecessarily.
*
* @param systime The time
*
* @return the date object
*/
private static Date getDate(long systime) {
Date date = localDate.get();
date.setTime(systime);
return date;
}
/**
* Find a locale by name.
*
* @param name The locale name
* @param fallback Fallback locale if the name is not found
*
* @return the locale object
*/
protected static Locale findLocale(String name, Locale fallback) {
if (name == null || name.isEmpty()) {
return Locale.getDefault();
} else {
for (Locale l : Locale.getAvailableLocales()) {
if (name.equals(l.toString())) {
return l;
}
}
}
log.error(sm.getString("accessLogValve.invalidLocale", name));
return fallback;
}
/**
* AccessLogElement writes the partial message into the buffer.
*/
protected interface AccessLogElement {
void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time);
}
/**
* Marks an AccessLogElement as needing to be have the value cached at the start of the request rather than just
* recorded at the end as the source data for the element may not be available at the end of the request. This
* typically occurs for remote network information, such as ports, IP addresses etc. when the connection is closed
* unexpectedly. These elements take advantage of these values being cached elsewhere on first request and do not
* cache the value in the element since the elements are state-less.
*/
protected interface CachedElement {
void cache(Request request);
}
/**
* write thread name - %I
*/
protected static class ThreadNameElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
RequestInfo info = request.getCoyoteRequest().getRequestProcessor();
if (info != null) {
buf.append(info.getWorkerThreadName());
} else {
buf.append('-');
}
}
}
/**
* write local IP address - %A
*/
protected static class LocalAddrElement implements AccessLogElement {
private final String localAddrValue;
public LocalAddrElement(boolean ipv6Canonical) {
String init;
try {
init = InetAddress.getLocalHost().getHostAddress();
} catch (Throwable e) {
ExceptionUtils.handleThrowable(e);
init = "127.0.0.1";
}
if (ipv6Canonical) {
localAddrValue = IPv6Utils.canonize(init);
} else {
localAddrValue = init;
}
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
buf.append(localAddrValue);
}
}
/**
* write remote IP address - %a
*/
protected class RemoteAddrElement implements AccessLogElement, CachedElement {
/**
* Type of address to log
*/
private static final String remoteAddress = "remote";
private static final String peerAddress = "peer";
private final RemoteAddressType remoteAddressType;
public RemoteAddrElement() {
remoteAddressType = RemoteAddressType.REMOTE;
}
public RemoteAddrElement(String type) {
switch (type) {
case remoteAddress:
remoteAddressType = RemoteAddressType.REMOTE;
break;
case peerAddress:
remoteAddressType = RemoteAddressType.PEER;
break;
default:
log.error(sm.getString("accessLogValve.invalidRemoteAddressType", type));
remoteAddressType = RemoteAddressType.REMOTE;
break;
}
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
String value = null;
if (remoteAddressType == RemoteAddressType.PEER) {
value = request.getPeerAddr();
} else {
if (requestAttributesEnabled) {
Object addr = request.getAttribute(REMOTE_ADDR_ATTRIBUTE);
if (addr == null) {
value = request.getRemoteAddr();
} else {
value = addr.toString();
}
} else {
value = request.getRemoteAddr();
}
}
if (ipv6Canonical) {
value = IPv6Utils.canonize(value);
}
buf.append(value);
}
@Override
public void cache(Request request) {
if (!requestAttributesEnabled) {
if (remoteAddressType == RemoteAddressType.PEER) {
request.getPeerAddr();
} else {
request.getRemoteAddr();
}
}
}
}
/**
* write remote host name - %h
*/
protected class HostElement implements AccessLogElement, CachedElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
String value = null;
if (requestAttributesEnabled) {
Object host = request.getAttribute(REMOTE_HOST_ATTRIBUTE);
if (host != null) {
value = host.toString();
}
}
if (value == null || value.length() == 0) {
value = request.getRemoteHost();
}
if (value == null || value.length() == 0) {
value = "-";
}
if (ipv6Canonical) {
value = IPv6Utils.canonize(value);
}
buf.append(value);
}
@Override
public void cache(Request request) {
if (!requestAttributesEnabled) {
request.getRemoteHost();
}
}
}
/**
* write remote logical username from identd (always returns '-') - %l
*/
protected static class LogicalUserNameElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
buf.append('-');
}
}
/**
* write request protocol - %H
*/
protected class ProtocolElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (requestAttributesEnabled) {
Object proto = request.getAttribute(PROTOCOL_ATTRIBUTE);
if (proto == null) {
buf.append(request.getProtocol());
} else {
buf.append(proto.toString());
}
} else {
buf.append(request.getProtocol());
}
}
}
/**
* write remote user that was authenticated (if any), else '-' - %u
*/
protected static class UserElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (request != null) {
String value = request.getRemoteUser();
if (value != null) {
escapeAndAppend(value, buf);
} else {
buf.append('-');
}
} else {
buf.append('-');
}
}
}
/**
* write date and time, in configurable format (default CLF) - %t or %{format}t
*/
protected class DateAndTimeElement implements AccessLogElement {
/**
* Format prefix specifying request start time
*/
private static final String requestStartPrefix = "begin";
/**
* Format prefix specifying response end time
*/
private static final String responseEndPrefix = "end";
/**
* Separator between optional prefix and rest of format
*/
private static final String prefixSeparator = ":";
/**
* Special format for seconds since epoch
*/
private static final String secFormat = "sec";
/**
* Special format for milliseconds since epoch
*/
private static final String msecFormat = "msec";
/**
* Special format for millisecond part of timestamp
*/
private static final String msecFractionFormat = "msec_frac";
/**
* The patterns we use to replace "S" and "SSS" millisecond formatting of SimpleDateFormat by our own handling
*/
private static final String msecPattern = "{#}";
private static final String tripleMsecPattern = msecPattern + msecPattern + msecPattern;
/* Our format description string, null if CLF */
private final String format;
/* Does the format string contain characters we need to escape */
private final boolean needsEscaping;
/* Whether to use begin of request or end of response as the timestamp */
private final boolean usesBegin;
/* The format type */
private final FormatType type;
/* Whether we need to postprocess by adding milliseconds */
private boolean usesMsecs = false;
protected DateAndTimeElement() {
this(null);
}
/**
* Replace the millisecond formatting character 'S' by some dummy characters in order to make the resulting
* formatted time stamps cacheable. We replace the dummy chars later with the actual milliseconds because that's
* relatively cheap.
*/
private String tidyFormat(String format) {
boolean escape = false;
StringBuilder result = new StringBuilder();
int len = format.length();
char x;
for (int i = 0; i < len; i++) {
x = format.charAt(i);
if (escape || x != 'S') {
result.append(x);
} else {
result.append(msecPattern);
usesMsecs = true;
}
if (x == '\'') {
escape = !escape;
}
}
return result.toString();
}
protected DateAndTimeElement(String sdf) {
String format = sdf;
boolean needsEscaping = false;
if (sdf != null) {
CharArrayWriter writer = new CharArrayWriter();
escapeAndAppend(sdf, writer);
String escaped = writer.toString();
if (!escaped.equals(sdf)) {
needsEscaping = true;
}
}
this.needsEscaping = needsEscaping;
boolean usesBegin = false;
FormatType type = FormatType.CLF;
if (format != null) {
if (format.equals(requestStartPrefix)) {
usesBegin = true;
format = "";
} else if (format.startsWith(requestStartPrefix + prefixSeparator)) {
usesBegin = true;
format = format.substring(6);
} else if (format.equals(responseEndPrefix)) {
usesBegin = false;
format = "";
} else if (format.startsWith(responseEndPrefix + prefixSeparator)) {
usesBegin = false;
format = format.substring(4);
}
if (format.length() == 0) {
type = FormatType.CLF;
} else if (format.equals(secFormat)) {
type = FormatType.SEC;
} else if (format.equals(msecFormat)) {
type = FormatType.MSEC;
} else if (format.equals(msecFractionFormat)) {
type = FormatType.MSEC_FRAC;
} else {
type = FormatType.SDF;
format = tidyFormat(format);
}
}
this.format = format;
this.usesBegin = usesBegin;
this.type = type;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
long timestamp = date.getTime();
long frac;
if (!usesBegin) {
timestamp += TimeUnit.NANOSECONDS.toMillis(time);
}
/*
* Implementation note: This is deliberately not implemented using switch. If a switch is used the compiler
* (at least the Oracle one) will use a synthetic class to implement the switch. The problem is that this
* class needs to be pre-loaded when using a SecurityManager and the name of that class will depend on any
* anonymous inner classes and any other synthetic classes. As such the name is not constant and keeping the
* pre-loading up to date as the name changes is error prone.
*/
if (type == FormatType.CLF) {
buf.append(localDateCache.get().getFormat(timestamp));
} else if (type == FormatType.SEC) {
buf.append(Long.toString(timestamp / 1000));
} else if (type == FormatType.MSEC) {
buf.append(Long.toString(timestamp));
} else if (type == FormatType.MSEC_FRAC) {
frac = timestamp % 1000;
if (frac < 100) {
if (frac < 10) {
buf.append('0');
buf.append('0');
} else {
buf.append('0');
}
}
buf.append(Long.toString(frac));
} else {
// FormatType.SDF
String temp = localDateCache.get().getFormat(format, locale, timestamp);
if (usesMsecs) {
frac = timestamp % 1000;
StringBuilder tripleMsec = new StringBuilder(4);
if (frac < 100) {
if (frac < 10) {
tripleMsec.append('0');
tripleMsec.append('0');
} else {
tripleMsec.append('0');
}
}
tripleMsec.append(frac);
temp = temp.replace(tripleMsecPattern, tripleMsec);
temp = temp.replace(msecPattern, Long.toString(frac));
}
if (needsEscaping) {
escapeAndAppend(temp, buf);
} else {
buf.append(temp);
}
}
}
}
/**
* write first line of the request (method and request URI) - %r
*/
protected static class RequestElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (request != null) {
String method = request.getMethod();
if (method == null) {
// No method means no request line
buf.append('-');
} else {
buf.append(request.getMethod());
buf.append(' ');
buf.append(request.getRequestURI());
if (request.getQueryString() != null) {
buf.append('?');
buf.append(request.getQueryString());
}
buf.append(' ');
buf.append(request.getProtocol());
}
} else {
buf.append('-');
}
}
}
/**
* write HTTP status code of the response - %s
*/
protected static class HttpStatusCodeElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (response != null) {
// This approach is used to reduce GC from toString conversion
int status = response.getStatus();
if (100 <= status && status < 1000) {
buf.append((char) ('0' + (status / 100))).append((char) ('0' + ((status / 10) % 10)))
.append((char) ('0' + (status % 10)));
} else {
buf.append(Integer.toString(status));
}
} else {
buf.append('-');
}
}
}
/**
* write local or remote port for request connection - %p and %{xxx}p
*/
protected class PortElement implements AccessLogElement, CachedElement {
/**
* Type of port to log
*/
private static final String localPort = "local";
private static final String remotePort = "remote";
private final PortType portType;
public PortElement() {
portType = PortType.LOCAL;
}
public PortElement(String type) {
switch (type) {
case remotePort:
portType = PortType.REMOTE;
break;
case localPort:
portType = PortType.LOCAL;
break;
default:
log.error(sm.getString("accessLogValve.invalidPortType", type));
portType = PortType.LOCAL;
break;
}
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (requestAttributesEnabled && portType == PortType.LOCAL) {
Object port = request.getAttribute(SERVER_PORT_ATTRIBUTE);
if (port == null) {
buf.append(Integer.toString(request.getServerPort()));
} else {
buf.append(port.toString());
}
} else {
if (portType == PortType.LOCAL) {
buf.append(Integer.toString(request.getServerPort()));
} else {
buf.append(Integer.toString(request.getRemotePort()));
}
}
}
@Override
public void cache(Request request) {
if (portType == PortType.REMOTE) {
request.getRemotePort();
}
}
}
/**
* write bytes sent, excluding HTTP headers - %b, %B
*/
protected static class ByteSentElement implements AccessLogElement {
private final boolean conversion;
/**
* @param conversion <code>true</code> to write '-' instead of 0 - %b.
*/
public ByteSentElement(boolean conversion) {
this.conversion = conversion;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
// Don't need to flush since trigger for log message is after the
// response has been committed
long length = response.getBytesWritten(false);
if (length <= 0) {
// Protect against nulls and unexpected types as these values
// may be set by untrusted applications
Object start = request.getAttribute(Globals.SENDFILE_FILE_START_ATTR);
if (start instanceof Long) {
Object end = request.getAttribute(Globals.SENDFILE_FILE_END_ATTR);
if (end instanceof Long) {
length = ((Long) end).longValue() - ((Long) start).longValue();
}
}
}
if (length <= 0 && conversion) {
buf.append('-');
} else {
buf.append(Long.toString(length));
}
}
}
/**
* write request method (GET, POST, etc.) - %m
*/
protected static class MethodElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (request != null) {
buf.append(request.getMethod());
}
}
}
/**
* write time taken to process the request - %D, %T
*/
protected static class ElapsedTimeElement implements AccessLogElement {
enum Style {
SECONDS {
@Override
public void append(CharArrayWriter buf, long time) {
buf.append(Long.toString(TimeUnit.NANOSECONDS.toSeconds(time)));
}
},
SECONDS_FRACTIONAL {
@Override
public void append(CharArrayWriter buf, long time) {
time = time / 1000000; // Convert to millis
buf.append(Long.toString(time / 1000));
buf.append('.');
int remains = (int) (time % 1000);
buf.append(Long.toString(remains / 100));
remains = remains % 100;
buf.append(Long.toString(remains / 10));
buf.append(Long.toString(remains % 10));
}
},
MILLISECONDS {
@Override
public void append(CharArrayWriter buf, long time) {
buf.append(Long.toString(TimeUnit.NANOSECONDS.toMillis(time)));
}
},
MICROSECONDS {
@Override
public void append(CharArrayWriter buf, long time) {
buf.append(Long.toString(TimeUnit.NANOSECONDS.toMicros(time)));
}
},
NANOSECONDS {
@Override
public void append(CharArrayWriter buf, long time) {
buf.append(Long.toString(time));
}
};
/**
* Append the time to the buffer in the appropriate format.
*
* @param buf The buffer to append to.
* @param time The time to log in nanoseconds.
*/
public abstract void append(CharArrayWriter buf, long time);
}
private final Style style;
/**
* Creates a new ElapsedTimeElement that will log the time in the specified style.
*
* @param style The elapsed-time style to use.
*/
public ElapsedTimeElement(Style style) {
this.style = style;
}
/**
* @param micros <code>true</code>, write time in microseconds - %D
* @param millis <code>true</code>, write time in milliseconds, if both arguments are <code>false</code>, write
* time in seconds - %T
*/
public ElapsedTimeElement(boolean micros, boolean millis) {
this(micros ? Style.MICROSECONDS : millis ? Style.MILLISECONDS : Style.SECONDS);
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
style.append(buf, time);
}
}
/**
* write time until first byte is written (commit time) in millis - %F
*/
protected static class FirstByteTimeElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
long commitTime = response.getCoyoteResponse().getCommitTimeNanos();
if (commitTime == -1) {
buf.append('-');
} else {
long delta = commitTime - request.getCoyoteRequest().getStartTimeNanos();
buf.append(Long.toString(TimeUnit.NANOSECONDS.toMillis(delta)));
}
}
}
/**
* write Query string (prepended with a '?' if it exists) - %q
*/
protected static class QueryElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
String query = null;
if (request != null) {
query = request.getQueryString();
}
if (query != null) {
buf.append('?');
buf.append(query);
}
}
}
/**
* write user session ID - %S
*/
protected static class SessionIdElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (request == null) {
buf.append('-');
} else {
Session session = request.getSessionInternal(false);
if (session == null) {
buf.append('-');
} else {
buf.append(session.getIdInternal());
}
}
}
}
/**
* write requested URL path - %U
*/
protected static class RequestURIElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (request != null) {
buf.append(request.getRequestURI());
} else {
buf.append('-');
}
}
}
/**
* write local server name - %v
*/
protected class LocalServerNameElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
String value = null;
if (requestAttributesEnabled) {
Object serverName = request.getAttribute(SERVER_NAME_ATTRIBUTE);
if (serverName != null) {
value = serverName.toString();
}
}
if (value == null || value.length() == 0) {
value = request.getServerName();
}
if (value == null || value.length() == 0) {
value = "-";
}
if (ipv6Canonical) {
value = IPv6Utils.canonize(value);
}
buf.append(value);
}
}
/**
* write any string
*/
protected static class StringElement implements AccessLogElement {
private final String str;
public StringElement(String str) {
this.str = str;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
buf.append(str);
}
}
/**
* write incoming headers - %{xxx}i
*/
protected static class HeaderElement implements AccessLogElement {
private final String header;
public HeaderElement(String header) {
this.header = header;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
Enumeration<String> iter = request.getHeaders(header);
if (iter.hasMoreElements()) {
escapeAndAppend(iter.nextElement(), buf);
while (iter.hasMoreElements()) {
buf.append(',');
escapeAndAppend(iter.nextElement(), buf);
}
return;
}
buf.append('-');
}
}
/**
* write a specific cookie - %{xxx}c
*/
protected static class CookieElement implements AccessLogElement {
private final String cookieNameToLog;
public CookieElement(String cookieNameToLog) {
this.cookieNameToLog = cookieNameToLog;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
StringBuilder value = null;
boolean first = true;
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookieNameToLog.equals(cookie.getName())) {
if (value == null) {
value = new StringBuilder();
}
if (first) {
first = false;
} else {
value.append(',');
}
value.append(cookie.getValue());
}
}
}
if (value == null) {
buf.append('-');
} else {
escapeAndAppend(value.toString(), buf);
}
}
}
/**
* write a specific response header - %{xxx}o
*/
protected static class ResponseHeaderElement implements AccessLogElement {
private final String header;
public ResponseHeaderElement(String header) {
this.header = header;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (null != response) {
Iterator<String> iter = response.getHeaders(header).iterator();
if (iter.hasNext()) {
escapeAndAppend(iter.next(), buf);
while (iter.hasNext()) {
buf.append(',');
escapeAndAppend(iter.next(), buf);
}
return;
}
}
buf.append('-');
}
}
/**
* write an attribute in the ServletRequest - %{xxx}r
*/
protected static class RequestAttributeElement implements AccessLogElement {
private final String attribute;
public RequestAttributeElement(String attribute) {
this.attribute = attribute;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
Object value = null;
if (request != null) {
value = request.getAttribute(attribute);
} else {
value = "??";
}
if (value != null) {
if (value instanceof String) {
escapeAndAppend((String) value, buf);
} else {
escapeAndAppend(value.toString(), buf);
}
} else {
buf.append('-');
}
}
}
/**
* write an attribute in the HttpSession - %{xxx}s
*/
protected static class SessionAttributeElement implements AccessLogElement {
private final String attribute;
public SessionAttributeElement(String attribute) {
this.attribute = attribute;
}
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
Object value = null;
if (null != request) {
HttpSession sess = request.getSession(false);
if (null != sess) {
value = sess.getAttribute(attribute);
}
} else {
value = "??";
}
if (value != null) {
if (value instanceof String) {
escapeAndAppend((String) value, buf);
} else {
escapeAndAppend(value.toString(), buf);
}
} else {
buf.append('-');
}
}
}
/**
* Write connection status when response is completed - %X
*/
protected static class ConnectionStatusElement implements AccessLogElement {
@Override
public void addElement(CharArrayWriter buf, Date date, Request request, Response response, long time) {
if (response != null && request != null) {
boolean statusFound = false;
// Check whether connection IO is in "not allowed" state
AtomicBoolean isIoAllowed = new AtomicBoolean(false);
request.getCoyoteRequest().action(ActionCode.IS_IO_ALLOWED, isIoAllowed);
if (!isIoAllowed.get()) {
buf.append('X');
statusFound = true;
} else {
// Check for connection aborted cond
if (response.isError()) {
Throwable ex = (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
if (ex instanceof ClientAbortException) {
buf.append('X');
statusFound = true;
}
}
}
// If status is not found yet, cont to check whether connection is keep-alive or close
if (!statusFound) {
String connStatus = response.getHeader(org.apache.coyote.http11.Constants.CONNECTION);
if (org.apache.coyote.http11.Constants.CLOSE.equalsIgnoreCase(connStatus)) {
buf.append('-');
} else {
buf.append('+');
}
}
} else {
// Unknown connection status
buf.append('?');
}
}
}
/**
* Parse pattern string and create the array of AccessLogElement.
*
* @return the log elements array
*/
protected AccessLogElement[] createLogElements() {
List<AccessLogElement> list = new ArrayList<>();
boolean replace = false;
StringBuilder buf = new StringBuilder();
for (int i = 0; i < pattern.length(); i++) {
char ch = pattern.charAt(i);
if (replace) {
/*
* For code that processes {, the behavior will be ... if I do not encounter a closing } - then I ignore
* the {
*/
if ('{' == ch) {
StringBuilder name = new StringBuilder();
int j = i + 1;
for (; j < pattern.length() && '}' != pattern.charAt(j); j++) {
name.append(pattern.charAt(j));
}
if (j + 1 < pattern.length()) {
/* the +1 was to account for } which we increment now */
j++;
list.add(createAccessLogElement(name.toString(), pattern.charAt(j)));
i = j; /* Since we walked more than one character */
} else {
// D'oh - end of string - pretend we never did this
// and do processing the "old way"
list.add(createAccessLogElement(ch));
}
} else {
list.add(createAccessLogElement(ch));
}
replace = false;
} else if (ch == '%') {
replace = true;
list.add(new StringElement(buf.toString()));
buf = new StringBuilder();
} else {
buf.append(ch);
}
}
if (buf.length() > 0) {
list.add(new StringElement(buf.toString()));
}
return list.toArray(new AccessLogElement[0]);
}
private CachedElement[] createCachedElements(AccessLogElement[] elements) {
List<CachedElement> list = new ArrayList<>();
for (AccessLogElement element : elements) {
if (element instanceof CachedElement) {
list.add((CachedElement) element);
}
}
return list.toArray(new CachedElement[0]);
}
/**
* Create an AccessLogElement implementation which needs an element name.
*
* @param name Header name
* @param pattern char in the log pattern
*
* @return the log element
*/
protected AccessLogElement createAccessLogElement(String name, char pattern) {
switch (pattern) {
case 'i':
return new HeaderElement(name);
case 'c':
return new CookieElement(name);
case 'o':
return new ResponseHeaderElement(name);
case 'a':
return new RemoteAddrElement(name);
case 'p':
return new PortElement(name);
case 'r':
if (TLSUtil.isTLSRequestAttribute(name)) {
tlsAttributeRequired = true;
}
return new RequestAttributeElement(name);
case 's':
return new SessionAttributeElement(name);
case 't':
return new DateAndTimeElement(name);
case 'T':
// ms for milliseconds, us for microseconds, and s for seconds
if ("ns".equals(name)) {
return new ElapsedTimeElement(ElapsedTimeElement.Style.NANOSECONDS);
} else if ("us".equals(name)) {
return new ElapsedTimeElement(ElapsedTimeElement.Style.MICROSECONDS);
} else if ("ms".equals(name)) {
return new ElapsedTimeElement(ElapsedTimeElement.Style.MILLISECONDS);
} else if ("fracsec".equals(name)) {
return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS_FRACTIONAL);
} else {
return new ElapsedTimeElement(false, false);
}
default:
return new StringElement("???");
}
}
/**
* Create an AccessLogElement implementation.
*
* @param pattern char in the log pattern
*
* @return the log element
*/
protected AccessLogElement createAccessLogElement(char pattern) {
switch (pattern) {
case 'a':
return new RemoteAddrElement();
case 'A':
return new LocalAddrElement(ipv6Canonical);
case 'b':
return new ByteSentElement(true);
case 'B':
return new ByteSentElement(false);
case 'D':
return new ElapsedTimeElement(true, false);
case 'F':
return new FirstByteTimeElement();
case 'h':
return new HostElement();
case 'H':
return new ProtocolElement();
case 'l':
return new LogicalUserNameElement();
case 'm':
return new MethodElement();
case 'p':
return new PortElement();
case 'q':
return new QueryElement();
case 'r':
return new RequestElement();
case 's':
return new HttpStatusCodeElement();
case 'S':
return new SessionIdElement();
case 't':
return new DateAndTimeElement();
case 'T':
return new ElapsedTimeElement(false, false);
case 'u':
return new UserElement();
case 'U':
return new RequestURIElement();
case 'v':
return new LocalServerNameElement();
case 'I':
return new ThreadNameElement();
case 'X':
return new ConnectionStatusElement();
default:
return new StringElement("???" + pattern + "???");
}
}
/*
* This method is intended to mimic the escaping performed by httpd and mod_log_config. mod_log_config escapes more
* elements than indicated by the documentation. See:
* https://github.com/apache/httpd/blob/trunk/modules/loggers/mod_log_config.c
*
* The following escaped elements are not supported by Tomcat: - %C cookie value (see %{}c below) - %e environment
* variable - %f filename - %l remote logname (always logs "-") - %n note - %R handler - %ti trailer request header
* - %to trailer response header - %V server name per UseCanonicalName setting
*
* The following escaped elements are not escaped in Tomcat because values that would require escaping are rejected
* before they reach the AccessLogValve: - %h remote host - %H request protocol - %m request method - %q query
* string - %r request line - %U request URI - %v canonical server name
*
* The following escaped elements are supported by Tomcat: - %{}i request header - %{}o response header - %u remote
* user
*
* The following additional Tomcat elements are escaped for consistency: - %{}c cookie value - %{}r request
* attribute - %{}s session attribute
*
* giving a total of 6 elements that are escaped in Tomcat.
*
* Quoting from the httpd docs: "...non-printable and other special characters in %r, %i and %o are escaped using
* \xhh sequences, where hh stands for the hexadecimal representation of the raw byte. Exceptions from this rule are
* " and \, which are escaped by prepending a backslash, and all whitespace characters, which are written in their
* C-style notation (\n, \t, etc)."
*
* Reviewing the httpd code, characters with the high bit set are escaped. The httpd is assuming a single byte
* encoding which may not be true for Tomcat so Tomcat uses the Java \\uXXXX encoding.
*/
protected static void escapeAndAppend(String input, CharArrayWriter dest) {
if (input == null || input.isEmpty()) {
dest.append('-');
return;
}
int len = input.length();
// As long as we don't encounter chars that need escaping,
// we only remember start and length of that string part.
// "next" is the start of the string part containing these chars,
// "current - 1" is its end. So writing from "next" with length
// "current - next" writes that part.
// We write that part whenever we find a character to escape and the
// unchanged and unwritten string part is not empty.
int next = 0;
char c;
for (int current = 0; current < len; current++) {
c = input.charAt(current);
// Fast path
if (c >= 32 && c < 127) {
// special case " and \
switch (c) {
case '\\': // dec 92
// Write unchanged string parts
if (current > next) {
dest.write(input, next, current - next);
}
next = current + 1;
dest.append("\\\\");
break;
case '\"': // dec 34
// Write unchanged string parts
if (current > next) {
dest.write(input, next, current - next);
}
next = current + 1;
dest.append("\\\"");
break;
// Don't output individual unchanged chars,
// write the sub string only when the first char to encode
// is encountered plus at the end.
default:
}
// Control (1-31), delete (127) or above 127
} else {
// Write unchanged string parts
if (current > next) {
dest.write(input, next, current - next);
}
next = current + 1;
switch (c) {
// Standard escapes for some control chars
case '\f': // dec 12
dest.append("\\f");
break;
case '\n': // dec 10
dest.append("\\n");
break;
case '\r': // dec 13
dest.append("\\r");
break;
case '\t': // dec 09
dest.append("\\t");
break;
// Unicode escape \\uXXXX
default:
dest.append("\\u");
dest.append(HexUtils.toHexString(c));
}
}
}
// Write remaining unchanged string parts
if (len > next) {
dest.write(input, next, len - next);
}
}
}