mirror of
https://github.com/apache/cloudstack.git
synced 2025-10-26 08:42:29 +01:00
1118 lines
44 KiB
HTML
1118 lines
44 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
|
<title>Apache log4j 1.2 - Frequently Asked Technical Questions</title>
|
|
<style type="text/css" media="all">
|
|
@import url("./css/maven-base.css");
|
|
@import url("./css/maven-theme.css");
|
|
@import url("./css/site.css");
|
|
</style>
|
|
<link rel="stylesheet" href="./css/print.css" type="text/css" media="print" />
|
|
</head>
|
|
<body class="composite">
|
|
<div id="banner">
|
|
<a href="../../" id="bannerLeft">
|
|
|
|
<img src="images/ls-logo.jpg" alt="" />
|
|
|
|
</a>
|
|
<a href=".." id="bannerRight">
|
|
|
|
<img src="images/logo.jpg" alt="" />
|
|
|
|
</a>
|
|
<div class="clear">
|
|
<hr/>
|
|
</div>
|
|
</div>
|
|
<div id="breadcrumbs">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<div class="xleft">
|
|
Last Published: 2010-03-30
|
|
|
|
|
<a href="http://www.apache.org/" class="externalLink">Apache</a>
|
|
>
|
|
|
|
<a href="../../">Logging Services</a>
|
|
>
|
|
|
|
<a href="../">log4j</a>
|
|
>
|
|
|
|
<a href="http://logging.apache.org:80/log4j/1.2/" class="externalLink">1.2</a>
|
|
</div>
|
|
<div class="xright">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
|
<div class="clear">
|
|
<hr/>
|
|
</div>
|
|
</div>
|
|
<div id="leftColumn">
|
|
<div id="navcolumn">
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<h5>Get log4j 1.2</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="download.html">Download</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="changes-report.html">Changes</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="license.html">License</a>
|
|
</li>
|
|
</ul>
|
|
<h5>About log4j 1.2</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="index.html">What is log4j?</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<strong>FAQ</strong>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="roadmap.html">Roadmap</a>
|
|
</li>
|
|
</ul>
|
|
<h5>Community</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="mail-lists.html">Mailing Lists</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="issue-tracking.html">Issue Tracking</a>
|
|
</li>
|
|
</ul>
|
|
<h5>Development</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="source-repository.html">Repository</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="jxr.html">Cross Reference</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="dependencies.html">Dependencies</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="integration.html">Continuous Integration</a>
|
|
</li>
|
|
</ul>
|
|
<h5>Documentation</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="manual.html">Introduction</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="apidocs/index.html">JavaDoc</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="publications.html">Publications</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="http://wiki.apache.org/logging-log4j" class="externalLink">Wiki</a>
|
|
</li>
|
|
</ul>
|
|
<h5>Apache</h5>
|
|
<ul>
|
|
|
|
<li class="none">
|
|
<a href="http://www.apache.org" class="externalLink">Home</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="http://www.apache.org/foundation/sponsorship.html" class="externalLink">Sponsorship</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="http://www.apache.org/foundation/thanks.html" class="externalLink">Thanks</a>
|
|
</li>
|
|
|
|
<li class="none">
|
|
<a href="http://www.apachecon.com" class="externalLink">Conferences</a>
|
|
</li>
|
|
</ul>
|
|
<a href="http://maven.apache.org/" title="Built by Maven" class="poweredBy">
|
|
<img alt="Built by Maven" src="./images/logos/maven-feather.png"></img>
|
|
</a>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
|
</div>
|
|
<div id="bodyColumn">
|
|
<div id="contentBox">
|
|
<div class="section"><h2><a name="top">Frequently Asked Technical Questions</a></h2>
|
|
<ol type="1"><li><a href="#a1.1">What is log4j?</a></li>
|
|
<li><a href="#a1.2">Is log4j a reliable logging system?</a></li>
|
|
<li><a href="#a1.3">What are the prerequisites for log4j?</a></li>
|
|
<li><a href="#a1.4">What are the features of log4j?</a></li>
|
|
<li><a href="#a1.5">Is there example code for using log4j?</a></li>
|
|
<li><a href="#a1.6">What documentation should I read to learn more about
|
|
log4j?</a></li>
|
|
<li><a href="#a1.7">Is log4j thread-safe?</a></li>
|
|
<li><a href="#a1.8">What does log output look like?</a></li>
|
|
<li><a href="#a1.9">Why should I use log4j when JDK 1.4 already ships with a
|
|
logging API?</a></li>
|
|
<li><a href="#a2.1">What are <em>Loggers</em>?</a></li>
|
|
<li><a href="#a2.2">How can I change log behavior at runtime?</a></li>
|
|
<li><a href="#a2.3">What is the fastest way of (not) logging?</a></li>
|
|
<li><a href="#a2.4">Are there any suggested ways for naming loggers?</a></li>
|
|
<li><a href="#a2.5">How do I get the fully-qualified name of a class in a static block?</a></li>
|
|
<li><a href="#a2.6">Can the log output format be customized? </a></li>
|
|
<li><a href="#a2.7">What are the configurable options for <code>FooBarAppender</code>?</a></li>
|
|
<li><a href="#a2.8">What is the recommended way of migrating from
|
|
java.util.logging to log4j?</a></li>
|
|
<li><a href="#a2.9">Is it possible to direct log output to
|
|
different appenders by level? </a></li>
|
|
<li><a href="#a2.10">What does the Windows NT Event Viewer complain about
|
|
missing descriptions for my event messages when I use the
|
|
<code>NTEventLogAppender</code>?</a></li>
|
|
<li><a href="#a2.11">Why can't I map my logger names to the loggers that
|
|
appear in the NT Event Log when I use the
|
|
NTEventLogAppender?</a></li>
|
|
<li><a href="#a2.12">Are there suggested approaches for logging in JSP pages?</a></li>
|
|
<li><a href="#a3.1">Can the outputs of multiple client request go to
|
|
different log files?</a></li>
|
|
<li><a href="#a3.2">Logger instances seem to be create only. Why isn't
|
|
there a method to remove logger instances?</a></li>
|
|
<li><a href="#a3.3">How do I get multiple process to log to the same file?</a></li>
|
|
<li><a href="#a3.4">How about the timesamps of events generated by multiple
|
|
processes across multiple hosts (possibly across multiple
|
|
timezones)?</a></li>
|
|
<li><a href="#a3.5">Why can't log4j find my properties file in a J2EE or WAR
|
|
application?</a></li>
|
|
<li><a href="#a3.6">Is there a way to get log4j to automatically reload a
|
|
configuration file if it changes?</a></li>
|
|
<li><a href="#a4.1">Why should I donate my extensions to log4j back to the
|
|
project?</a></li>
|
|
<li><a href="#a4.2">What should I keep in mind when contributing code?</a></li>
|
|
<li><a href="#duplicate-messages">Why am I getting multiple copies of messages in my log file?</a></li>
|
|
<li><a href="#custom-level">How do I add a custom level?</a></li>
|
|
<li><a href="#unload">Why does log4j throw a NullPointerException or
|
|
print a message about NOPLoggerRepository
|
|
when shutting down or restarting under Tomcat or during a shutdown
|
|
hook?</a></li>
|
|
<li><a href="#rfa">Why isn't my rolling file appender properly rolling files or why does
|
|
logging events get written to the old log file?</a></li>
|
|
<li><a href="#noconfig">
|
|
Why do I see a warning about "No appenders found for logger" and
|
|
"Please configure log4j properly"?
|
|
</a></li>
|
|
<li><a href="#sysprops">What system properties are checked by log4j?</a></li>
|
|
</ol>
|
|
</div>
|
|
<dl><dt><a name="a1.1">What is log4j?</a></dt>
|
|
<dd> <p>log4j is a tool to help the programmer output log statements to a
|
|
variety of output targets.
|
|
</p>
|
|
|
|
<p>In case of problems with an application, it is helpful to
|
|
enable logging so that the problem can be located. With log4j
|
|
it is possible to enable logging at runtime without modifying
|
|
the application binary. The log4j package is designed so that
|
|
log statements can remain in <i>shipped</i> code without
|
|
incurring a high performance cost. It follows that the speed
|
|
of logging (or rather not logging) is capital.
|
|
</p>
|
|
|
|
<p>At the same time, log output can be so voluminous that it quickly
|
|
becomes overwhelming. One of the distinctive features of log4j is the
|
|
notion of <i>hierarchical loggers</i>. Using loggers it is
|
|
possible to selectively control which log statements are output at
|
|
arbitrary granularity.
|
|
</p>
|
|
|
|
<p>log4j is designed with three goals in mind:
|
|
reliability, speed and flexibility. There is a tight balance
|
|
between these requirements. We believe that log4j strikes the
|
|
right balance.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.2">Is log4j a reliable logging system?</a></dt>
|
|
<dd><p>No. log4j is not reliable. It is a best-effort
|
|
<em>fail-stop</em> logging system.
|
|
</p>
|
|
|
|
<p>By fail-stop, we mean that log4j will not throw unexpected
|
|
exceptions at run-time potentially causing your application to
|
|
crash. <b>If for any reason, log4j throws an uncaught exception,
|
|
please send an email to the <a href="mailto:log4j-user@logging.apache.org">log4j-user@logging.apache.org</a>
|
|
mailing list</b>. Uncaught exceptions are handled as serious bugs
|
|
requiring immediate attention.
|
|
</p>
|
|
|
|
<p>Moreover, log4j will not revert to System.out or System.err
|
|
when its designated output stream is not opened, is not writable or
|
|
becomes full. This avoids corrupting an otherwise working program by
|
|
flooding the user's terminal because logging fails. However, log4j
|
|
will output a single message to System.err indicating that logging can
|
|
not be performed.
|
|
</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.3">What are the prerequisites for log4j?</a></dt>
|
|
<dd>
|
|
<p>Log4j 1.2.8 and earlier are compatible with JDK 1.1.x and later, later versions
|
|
of log4j 1.2 are compatible with JDK 1.2 and later.
|
|
</p>
|
|
|
|
<p>The DOMConfigurator is based on the DOM Level 1
|
|
API. The DOMConfigurator.configure(Element) method will work
|
|
with any XML parser that will pass it a DOM tree.
|
|
</p>
|
|
<p>The DOMConfigurator.configure(String filename) method and its
|
|
variants require a JAXP compatible XML parser, for example <a href="http://xml.apache.org/">Xerces</a> or Sun's
|
|
parser. Compiling the DOMConfigurator requires the presence of a
|
|
JAXP parser in the classpath.
|
|
</p>
|
|
|
|
<p>The <code>org.apache.log4j.net.SMTPAppender</code>
|
|
relies on the <a href="http://java.sun.com/products/javamail/">JavaMail
|
|
API</a>. It has been tested with JavaMail API version
|
|
1.2. The JavaMail API requires the <a href="http://java.sun.com/beans/glasgow/jaf.html">JavaBeans
|
|
Activation Framework</a> package.
|
|
</p>
|
|
|
|
<p>The <code>org.apache.log4j.net.JMSAppender</code>
|
|
requires the presence of the JMS API as well as JNDI.
|
|
</p>
|
|
|
|
<p>log4j test code relies on the <a href="http://www.junit.org">JUnit</a> testing framework.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.4">What are the features of log4j?</a></dt>
|
|
<dd>
|
|
<p>log4j is optimized for speed.</p>
|
|
|
|
<p>log4j is based on a named logger hierarchy.</p>
|
|
|
|
<p>log4j is fail-stop. However, altough it certainly
|
|
strives to ensure delivery, log4j does not guarantee that
|
|
each log statement will be delivered to its destination.
|
|
</p>
|
|
|
|
<p>log4j is thread-safe.</p>
|
|
|
|
<p>log4j is not restricted to a predefined set of
|
|
facilities.</p>
|
|
|
|
<p>Logging behavior can be set at runtime using a
|
|
configuration file. Configuration files can be property
|
|
files or in XML format. </p>
|
|
|
|
<p>log4j is designed to handle Java Exceptions from the
|
|
start.</p>
|
|
|
|
<p>log4j can direct its output to a file, the console,
|
|
an <code>java.io.OutputStream</code>,
|
|
<code>java.io.Writer</code>, a remote server using TCP, a
|
|
remote Unix Syslog daemon, to a remote listener using JMS,
|
|
to the NT EventLog or even send e-mail. </p>
|
|
|
|
<p>log4j uses 6 levels, namely TRACE, DEBUG, INFO, WARN, ERROR and
|
|
FATAL.
|
|
</p>
|
|
|
|
<p>The format of the log output can be easily changed by
|
|
extending the <code>Layout</code>
|
|
class. </p>
|
|
|
|
<p>The target of the log output as well as the writing
|
|
strategy can be altered by implementations of the
|
|
<code>Appender</code> interface. </p>
|
|
|
|
<p>log4j supports multiple output appenders per logger.
|
|
</p>
|
|
|
|
<p>log4j supports internationalization.</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.5">Is there example code for using log4j?</a></dt>
|
|
<dd>
|
|
<p>See the <code>examples/</code> directory.</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.6">What documentation should I read to learn more about
|
|
log4j?</a></dt>
|
|
<dd><p>Make sure to read the <a href="manual.html">short
|
|
manual</a>. It is also recommended to you read <a href="https://www.qos.ch/shop/products/log4j/log4j-Manual.jsp">The complete
|
|
log4j manual</a> which is much more detailed and up to
|
|
date. Both documents were written by Ceki Gülcü.
|
|
</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.7">Is log4j thread-safe?</a></dt>
|
|
<dd>
|
|
<p>Yes, log4j is thread-safe. Log4j components are designed to
|
|
be used in heavily multithreaded systems.</p>
|
|
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.8">What does log output look like?</a></dt>
|
|
<dd>
|
|
<p>The log output can be customized in many ways. Moreover,
|
|
one can completely override the output format by implementing
|
|
one's own Layout.
|
|
</p>
|
|
|
|
<p>Here is an example output using <em>PatternLayout</em> with
|
|
the conversion pattern <b>"%r [%t] %-5p %c{2} %x - %m%n"</b>
|
|
</p>
|
|
|
|
<pre class="screen_output">
|
|
176 [main] INFO examples.Sort - Populating an array of 2 elements in reverse order.
|
|
225 [main] INFO examples.SortAlgo - Entered the sort method.
|
|
262 [main] DEBUG SortAlgo.OUTER i=1 - Outer loop.
|
|
276 [main] DEBUG SortAlgo.SWAP i=1 j=0 - Swapping intArray[0] = 1 and intArray[1] = 0
|
|
290 [main] DEBUG SortAlgo.OUTER i=0 - Outer loop.
|
|
304 [main] INFO SortAlgo.DUMP - Dump of interger array:
|
|
317 [main] INFO SortAlgo.DUMP - Element [0] = 0
|
|
331 [main] INFO SortAlgo.DUMP - Element [1] = 1
|
|
343 [main] INFO examples.Sort - The next log statement should be an error message.
|
|
346 [main] ERROR SortAlgo.DUMP - Tried to dump an uninitialized array.
|
|
at org.log4j.examples.SortAlgo.dump(SortAlgo.java:58)
|
|
at org.log4j.examples.Sort.main(Sort.java:64)
|
|
467 [main] INFO examples.Sort - Exiting main method.
|
|
</pre>
|
|
|
|
<p>The first field is the number of milliseconds elapsed since
|
|
the start of the program. The second field is the thread
|
|
outputting the log statement. The third field is the level of
|
|
the log statement. The fourth field is the rightmost two
|
|
components of the logger making the log request. The fifth
|
|
field (just before the '-') is the <em>nested diagnostic
|
|
context</em> (NDC). Note the nested diagnostic context may be
|
|
empty as in the first two statements. The text after the '-'
|
|
is the message of the statement.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a1.9">Why should I use log4j when JDK 1.4 already ships with a
|
|
logging API?</a></dt>
|
|
<dd>
|
|
|
|
<p>
|
|
Although both APIs are conceptually similar, the log4j API is
|
|
significantly more flexible and offers many more features, too
|
|
numerous to be listed here. You will discover that the
|
|
additional features and flexibility turn out to be
|
|
indispensable in the context of a mission-critical
|
|
application.
|
|
</p>
|
|
|
|
<p>The open and collaborative way in which log4j is developped
|
|
ensures that it continues to preserve and even widen its
|
|
competitive edge. At some point, input from bright developers
|
|
from all over the world is bound to make a difference.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.1">What are <em>Loggers</em>?</a></dt>
|
|
<dd>
|
|
|
|
<p>Lggers lie at the heart of log4j. Loggers define a hierarchy and give
|
|
the programmer <em>run-time</em> control on which statements are
|
|
printed or not.
|
|
</p>
|
|
|
|
<p>Loggers are assigned levels. A log statement is printed
|
|
depending on its level <em>and</em> its logger.
|
|
</p>
|
|
|
|
<p>Make sure to read the <a href="manual.html">log4j manual</a>
|
|
for more information.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.2">How can I change log behavior at runtime?</a></dt>
|
|
<dd>
|
|
<p>Log behavior can be set using configuration files which are parsed
|
|
at runtime. Using configuration files the programmer can define
|
|
loggers and set their levels.
|
|
</p>
|
|
|
|
<p>The <code>PropertyConfigurator</code> defines a particular format
|
|
of a configuration file. See also the <code>examples/Sort.java</code>
|
|
example and associated configuration files.
|
|
</p>
|
|
|
|
<p>Configuration files can be specified in XML. See
|
|
<code>log4j.dtd</code> and
|
|
<code>org.log4j.xml.DOMConfigurator</code> for more details.
|
|
</p>
|
|
|
|
<p>See the various Layout and Appender components for specific
|
|
configuration options.
|
|
</p>
|
|
|
|
<p>In addition to configuration files, the user may disable all
|
|
messages belonging to a set of levels. See next item.
|
|
</p>
|
|
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.3">What is the fastest way of (not) logging?</a></dt>
|
|
<dd>
|
|
<p> For some logger <code>l</code>, writing,
|
|
</p>
|
|
|
|
<pre class="source">
|
|
l.debug("Entry number: " + i + " is " + String.valueOf(entry[i]));
|
|
</pre>
|
|
|
|
<p>incurs the cost of constructing the message parameter, that is
|
|
converting both integer <code>i</code> and <code>entry[i]</code> to a
|
|
String, and concatenating intermediate strings. This, regardless of
|
|
whether the message will be logged or not.
|
|
</p>
|
|
|
|
<p>If you are worried about speed, then write</p>
|
|
<pre class="source">
|
|
if(l.isDebugEnabled()) {
|
|
l.debug("Entry number: " + i + " is " + String.valueOf(entry[i]));
|
|
}
|
|
</pre>
|
|
<p>or using LogMF from the extras companion write</p>
|
|
<pre class="source">
|
|
LogMF.debug(logger, "Entry number: {0} is {1}", i, entry[i]);
|
|
</pre>
|
|
|
|
<p>This way you will not incur the cost of parameter
|
|
construction if debugging is disabled for logger
|
|
<code>l</code>. On the other hand, if the logger is debug
|
|
enabled, you will incur the cost of evaluating whether the
|
|
logger is enabled or not, twice: once in
|
|
<code>debugEnabled</code> and once in <code>debug</code>.
|
|
This is an insignificant overhead since evaluating a logger
|
|
takes less than 1% of the time it takes to actually log a
|
|
statement.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.4">Are there any suggested ways for naming loggers?</a></dt>
|
|
<dd>
|
|
<p>Yes, there are.</p>
|
|
|
|
<p>You can name loggers by <strong>locality</strong>. It turns out
|
|
that instantiating a logger in each class, with the logger name
|
|
equal to the fully-qualified name of the class, is a useful and
|
|
straightforward approach of defining loggers. This approach has
|
|
many benefits:
|
|
</p>
|
|
|
|
<ul>
|
|
<li>It is very simple to implement.</li>
|
|
|
|
<li>It is very simple to explain to new developers.</li>
|
|
|
|
<li>It automatically mirrors your application's own modular design.
|
|
</li>
|
|
<li>It can be further refined at will.</li>
|
|
|
|
<li>Printing the logger automatically gives information on the locality
|
|
of the log statement. </li>
|
|
</ul>
|
|
|
|
<p>However, this is not the only way for naming loggers. A
|
|
common alternative is to name loggers by <strong>functional
|
|
areas</strong>. For example, the "database" logger, "RMI"
|
|
logger, "security" logger, or the "XML" logger.
|
|
</p>
|
|
|
|
<p>You may choose to name loggers by functionality and
|
|
subcategorize by locality, as in "DATABASE.com.foo.some.package.someClass" or
|
|
"DATABASE.com.foo.some.other.package.someOtherClass".
|
|
</p>
|
|
|
|
<p><em>You are totally free in choosing the names of your
|
|
loggers.</em> The log4j package merely allows you to manage your
|
|
names in a hierarchy. However, it is your responsibility to define
|
|
this hierarchy.
|
|
</p>
|
|
|
|
<p>Note by naming loggers by locality one tends to name things by
|
|
functionality, since in most cases the locality relates closely to
|
|
functionality.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.5">How do I get the fully-qualified name of a class in a static block?</a></dt>
|
|
<dd>
|
|
<p>You can easily retrieve the fully-qualified name of a class in a
|
|
static block for class X, with the statement
|
|
<code>X.class.getName()</code>. Note that <code>X</code> is the class
|
|
name and not an instance. The <code>X.class</code> statement does
|
|
<i>not</i> create a new instance of class <code>X</code>.
|
|
</p>
|
|
|
|
<p>Here is the suggested usage template:</p>
|
|
|
|
<pre class="source">
|
|
package a.b.c;
|
|
|
|
public class Foo {
|
|
final static Logger logger = Logger.getLogger(Foo.class);
|
|
... other code
|
|
|
|
}
|
|
</pre>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.6">Can the log output format be customized? </a></dt>
|
|
<dd>
|
|
<p>Yes, you can extend the <code>Layout</code> class to create
|
|
you own customized log format. Appenders can be parameterized
|
|
to use the layout of your choice.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.7">What are the configurable options for <code>FooBarAppender</code>?</a></dt>
|
|
<dd>
|
|
<p>Log4j uses JavaBeans style configuration.</p>
|
|
|
|
<p>Thus, any setter method in <code>FooBarAppender</code>
|
|
corresponds to a configurable option. For example, in <a href="apidocs\org\apache\log4j\RollingFileAppender.html"><code>RollingFileAppender</code></a>
|
|
the <a href="apidocs/org/apache/log4j/RollingFileAppender.html#setMaxBackupIndex(int)"><code>setMaxBackupIndex(int
|
|
maxBackups)</code></a> method corresponds to the
|
|
<code>maxBackupIndex</code> option. The first letter of the
|
|
option can be upper case, i.e. <code>MaxBackupIndex</code>
|
|
and <code>maxBackupIndex</code> are equivalent but not
|
|
<code>MAXBACKUPIndex</code> nor <code>mAXBackupIndex</code>.
|
|
</p>
|
|
|
|
<p>Layouts options are also defined by their setter methods. The same goes
|
|
for most other log4j components.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.8">What is the recommended way of migrating from
|
|
java.util.logging to log4j?</a></dt>
|
|
<dd>
|
|
|
|
<p>We suggest to just use global file search/replace. You should be able
|
|
to replace all the "java.util.Logger" references with
|
|
"org.apache.log4j.Logger", and you should be on your way.
|
|
</p>
|
|
|
|
<p>If you're on a Win32 platform, we recommend <a href="http://www.textpad.com/">Textpad</a>. You can use the
|
|
CTRL+SHIFT+O to open all *.java files from a directory including all
|
|
its sub-directories, and then use the search/replace function to
|
|
replace in all files, and then CTRL+SHIFT+S to save all. Should take
|
|
about 60 seconds! :)
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.9">Is it possible to direct log output to
|
|
different appenders by level? </a></dt>
|
|
<dd>
|
|
<p>Yes it is. Setting the <b>Threshold</b> option of any appender
|
|
extending <a href="api/org/apache/log4j/AppenderSkeleton.html">AppenderSkeleton</a>,
|
|
(most log4j appenders extend AppenderSkeleton) to filter out all log
|
|
events with <em>lower</em> level than the value of the threshold
|
|
option.
|
|
</p>
|
|
|
|
<p>For example, setting the threshold of an appender to DEBUG
|
|
also allow INFO, WARN, ERROR and FATAL messages to log along
|
|
with DEBUG messages. This is usually acceptable as there is
|
|
little use for DEBUG messages without the surrounding INFO,
|
|
WARN, ERROR and FATAL messages. Similarly, setting the
|
|
threshold of an appender to ERROR will filter out DEBUG, INFO
|
|
and WARN messages but not ERROR or FATAL messages.
|
|
</p>
|
|
|
|
<p>This policy usually best encapsulates what the user
|
|
actually wants to do, as opposed to her mind-projected
|
|
solution.
|
|
</p>
|
|
<p>See <i>examples/sort4.lcf</i> for an example threshold
|
|
configuration.</p>
|
|
|
|
<p>If you must filter events by exact level match, then you can
|
|
attach a <a href="apidocs/org/apache/log4j/varia/LevelMatchFilter.html">LevelMatchFilter</a>
|
|
to any appender to filter out logging events by exact level match.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.10">What does the Windows NT Event Viewer complain about
|
|
missing descriptions for my event messages when I use the
|
|
<code>NTEventLogAppender</code>?</a></dt>
|
|
<dd>
|
|
<p>The NT Event Viewer relies on <i>message resource</i> DLLs
|
|
to properly view an event message. The NTEventLogAppender.dll
|
|
contains these message resources, but that DLL must be copied
|
|
to %SYSTEMROOT%\SYSTEM32 for it to work properly.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.11">Why can't I map my logger names to the loggers that
|
|
appear in the NT Event Log when I use the
|
|
NTEventLogAppender?</a></dt>
|
|
<dd>
|
|
<p>Unfotunately, the logger names are hardcoded within the
|
|
message resource DLL (see previous question about
|
|
NTEventLogAppender), so there isn't any easy way to override
|
|
those dynamically... in fact, I don't think it's possible to
|
|
do it, as you'd have to modify the DLL resources for every
|
|
application. Since most native applications don't use the
|
|
Logger column anyway...
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a2.12">Are there suggested approaches for logging in JSP pages?</a></dt>
|
|
<dd>
|
|
<p>
|
|
The suggested approach depends on your design requirements. If you or
|
|
your organization has no constraints on the use of Java in JSP pages,
|
|
simply use log4j normally in <code><% ... %></code> statements
|
|
as indicated in the Short Manual and the rest of the documentation.
|
|
</p>
|
|
<p>
|
|
However, if your design calls for a minimum amount of Java in your JSP
|
|
pages, consider using the
|
|
<a href="http://jakarta.apache.org/taglibs/doc/log-doc/intro.html">Log Taglib</a>
|
|
from the Jakarta Taglibs project. It provides logging JSP tags that invoke
|
|
log4j.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.1">Can the outputs of multiple client request go to
|
|
different log files?</a></dt>
|
|
<dd>
|
|
<p>Many developers are confronted with the problem of
|
|
distinguishing the log output originating from the same class
|
|
but different client requests. They come up with ingenious
|
|
mechanisms to fan out the log output to different files. In
|
|
most cases, this is not the right approach.
|
|
</p>
|
|
|
|
<p>It is simpler to use a nested diagnostic context
|
|
(NDC). Typically, one would <em>NDC.push()</em> client
|
|
specific information, such as the client's hostname, ID or any
|
|
other distinguishing information when starting to handle the
|
|
client's request. Thereafter, log output will automatically
|
|
include the nested diagnostic context so that you can
|
|
distinguish logs from different client requests even if they
|
|
are output to the same file.
|
|
</p>
|
|
|
|
<p>See the <code>NDC</code> and the <code>PatternLayout</code>
|
|
classes for more information. The <code>NumberCruncher</code>
|
|
example shows how the NDC can be used to distinguish the log
|
|
output from multiple clients even if they share the same log
|
|
file.
|
|
</p>
|
|
|
|
<p>For select applications, such as virtual hosting
|
|
web-servers, the NDC solution is not sufficient. As of version
|
|
0.9.0, log4j supports multiple hierarchy trees. Thus, it is
|
|
possible to log to different targets from the same logger
|
|
depending on the current context.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.2">Logger instances seem to be create only. Why isn't
|
|
there a method to remove logger instances?</a></dt>
|
|
<dd>
|
|
<p>It is quite nontrivial to define the semantics of a
|
|
"removed" logger escecially if it is still referenced by the
|
|
user. Future releases <em>may</em> include a remove method in
|
|
the Logger class.</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.3">How do I get multiple process to log to the same file?</a></dt>
|
|
<dd>
|
|
<p>You may have each process log to a
|
|
<a href="apidocs/org/apache/log4j/net/SocketAppender.html"><code>SocketAppender</code></a>.
|
|
The receiving
|
|
<a href="apidocs/org/apache/log4j/net/SocketServer.html"><code>SocketServer</code></a>
|
|
(or
|
|
<a href="apidocs/org/apache/log4j/net/SimpleSocketServer.html"><code>SimpleSocketServer</code></a>)
|
|
can receive all the events and send them to a single
|
|
log file.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.4">How about the timesamps of events generated by multiple
|
|
processes across multiple hosts (possibly across multiple
|
|
timezones)?</a></dt>
|
|
<dd>
|
|
<p>The timestamp is created when the logging event is created.
|
|
That is so say, when the <code>debug</code>,
|
|
<code>info</code>, <code>warn</code>, <code>error</code> or
|
|
<code>fatal</code> method is invoked. Thus, the timestamp is
|
|
unaffected by the time at which event arrive at a remote
|
|
socket server.
|
|
</p>
|
|
|
|
<p>Timestamps are stored in UTC format inside the
|
|
event. Consequently, when displayed or written to a log file,
|
|
timestamps appear in the same timezone as the host displaying
|
|
or creating the logfile. Note that because the clocks of
|
|
various machines may not be synchronized, there may be
|
|
timestamp inconsistencies between events generated on
|
|
different hosts. The EnhancedPatternLayout in the extras companion
|
|
supports explicit specification of the timezone using a pattern like
|
|
"%d{HH:mm}{GMT}".
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.5">Why can't log4j find my properties file in a J2EE or WAR
|
|
application?</a></dt>
|
|
<dd>
|
|
<p>The short answer: the log4j classes and the properties file
|
|
are not within the scope of the same classloader.
|
|
</p>
|
|
|
|
<p>The long answer (and what to do about it): J2EE or Servlet
|
|
containers utilize Java's class loading system. Sun changed
|
|
the way classloading works with the release of Java 2. In
|
|
Java 2, classloaders are arranged in a hierarchial
|
|
parent-child relationship. When a child classloader needs to
|
|
find a class or a resource, it first delegates the request to
|
|
the parent.
|
|
</p>
|
|
|
|
<p>Log4j only uses the default <code>Class.forName()</code>
|
|
mechanism for loading classes. Resources are handled
|
|
similarly. See the documentation for
|
|
<code>java.lang.ClassLoader</code> for more details.
|
|
</p>
|
|
|
|
<p>So, if you're having problems, try loading the class or
|
|
resource yourself. If you can't find it, neither will
|
|
log4j. ;)
|
|
</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a3.6">Is there a way to get log4j to automatically reload a
|
|
configuration file if it changes?</a></dt>
|
|
<dd>
|
|
|
|
<p>Yes. Both the DOMConfigurator and the PropertyConfigurator support
|
|
automatic reloading through the <code>configureAndWatch</code> method.
|
|
See the API documentation for more details.
|
|
</p>
|
|
|
|
|
|
<p>Because the <code>configureAndWatch</code> launches a
|
|
separate wathdog thread, and because there is no way to stop
|
|
this thread in log4j 1.2, the <code>configureAndWatch</code>
|
|
method is unsafe for use in J2EE envrironments where
|
|
applications are recycled.
|
|
</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a4.1">Why should I donate my extensions to log4j back to the
|
|
project?</a></dt>
|
|
<dd>
|
|
<p>Contrary to the GNU Public License (GPL) the Apache
|
|
Software License does not make any claims over your
|
|
extensions. By extensions, we mean totally new code that
|
|
invokes existing log4j classes. <em>You are free to do
|
|
whatever you wish with your proprietary log4j extensions.</em>
|
|
In particular, you may choose to never release your extensions
|
|
to the wider public.
|
|
</p>
|
|
|
|
<p>We are very careful not to change the log4j client API so
|
|
that newer log4j releases are backward compatible with
|
|
previous versions. We are a lot less scrupulous with the
|
|
internal log4j API. Thus, if your extension is designed to
|
|
work with log4j version <code>n</code>, then when log4j
|
|
release version <code>n+1</code> comes out, you will probably
|
|
need to adapt your proprietary extensions to the new release.
|
|
</p>
|
|
|
|
<p>Thus, you will be forced to spend precious resources in
|
|
order to keep up with log4j changes. This is commonly referred
|
|
to as the "stupid-tax." By donating the code and making it
|
|
part of the standard distribution, you save yourself the
|
|
unnecessary maintenance work.
|
|
</p>
|
|
|
|
<p>If your extensions are useful then someone will eventually
|
|
write an extension providing the same or very similar
|
|
functionality. Your development effort will be wasted. Unless
|
|
the proprietary log4j extension is business critical, there is
|
|
little reason for not donating your extensions back to the
|
|
project.
|
|
</p><table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="a4.2">What should I keep in mind when contributing code?</a></dt>
|
|
<dd>
|
|
<ol>
|
|
|
|
<li>
|
|
<p>Write a test case for your contribution.</p>
|
|
|
|
<p>There is nothing more irritating than finding the bugs
|
|
in debugging (i.e. logging) code. Writing a test case
|
|
takes some effort but is crucial for a widely used library
|
|
such as log4j. Writing a test case will go a long way in
|
|
earning you the respect of fellow developers. See the
|
|
tests/ directory for exiting test cases.
|
|
</p>
|
|
</li>
|
|
|
|
|
|
<li>
|
|
<p>Stick to the existing indentation style even if you hate it.</p>
|
|
|
|
<p>Alternating between indentation styles makes it hard to
|
|
understand the source code. Make it a little harder on
|
|
yourself but easier on others.
|
|
</p>
|
|
|
|
<p>Log4j has adopted a rather conservative approach by
|
|
following the <a href="http://java.sun.com/docs/codeconv/">Code Conventions
|
|
for the JavaTM Programming Language</a>. <b>We use 2 (two)
|
|
spaces for indentation and no tabs.</b>
|
|
</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Please do not both modify the code and change the
|
|
indentation in a single commit.</p>
|
|
|
|
<p>If you change the code and reformat it at the same time
|
|
and then commit, the commit notification message will be
|
|
hard to read. It will contain many diffs associated with
|
|
the reformatting in addition to logical changes.
|
|
</p>
|
|
|
|
<p>If you must reformat and change the code, then perform
|
|
each step separately. For example, reformat the code and
|
|
commit. Following that, you can change the logic and
|
|
commit. The two steps can be performed in the reverse
|
|
order just as well. You can first change the logic and
|
|
commit and only later reformat and commit.
|
|
</p>
|
|
|
|
</li>
|
|
<li>
|
|
<p>Make every effort to stick to the JDK 1.1 API.</p>
|
|
|
|
<p>One of the important advantages of log4j is its
|
|
compatibility with JDK 1.1.x.
|
|
</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Always keep it simple, small and fast when
|
|
possible.</p>
|
|
|
|
<p>It's all about the application not about logging.</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p>Identify yourself as a contributor at the top of the
|
|
relevant file.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>Take responsibility for your code.</p>
|
|
|
|
<p>Authoring software is very much like running a marathon. It
|
|
takes time and endurance.
|
|
</p>
|
|
</li>
|
|
<li>
|
|
<p>Did we mention sticking with the indentation style?</p>
|
|
</li>
|
|
<li><p>Did we mention writing test cases?</p>
|
|
</li>
|
|
|
|
</ol>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="duplicate-messages">Why am I getting multiple copies of messages in my log file?</a></dt>
|
|
<dd>
|
|
<p>There are several reasons this can occur:
|
|
<ul>
|
|
<li>Repeated configuration of log4j: By default, each call to
|
|
PropertyConfigurator.configure or DOMConfigurator.configure is
|
|
culmulative. If your configuration file defines a file appender,
|
|
calling PropertyConfigurator.configure three times will create
|
|
three distinct instances and connect each of them to the specified logger.</li>
|
|
<li>Attaching the same appender to multiple loggers: if an appender is
|
|
attached to the root logger and child logger, then any message
|
|
sent to the child logger will go to the appender twice (unless
|
|
additivity is set to false).</li>
|
|
</ul></p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="custom-level">How do I add a custom level?</a></dt>
|
|
<dd>
|
|
<p>It is possible, but rarely appropriate. The
|
|
request is commonly for a level named something like "audit"
|
|
that doesn't obviously fit in the progression "trace", "debug",
|
|
"info", "warn", "error" and "fatal". In that case, the request
|
|
for a level is really a request for a mechanism to specify
|
|
a different audience. The appropriate mechanism is to use a distinct
|
|
logger name (or tree) for "audit" related messages.</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="unload">Why does log4j throw a NullPointerException or
|
|
print a message about NOPLoggerRepository
|
|
when shutting down or restarting under Tomcat or during a shutdown
|
|
hook?</a></dt>
|
|
<dd><p>Tomcat will, by default,
|
|
clear all static members when unloading classes, however
|
|
this process can trigger initialization of classes which may
|
|
then call a class that has been cleared resulting in a
|
|
NullPointerException or some undesirable behavior.
|
|
Bug <a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=40212">40212</a>)
|
|
describes the problem in detail and has a patch which at this writing
|
|
has not been applied to Tomcat. Glassfish had a similar problem
|
|
and accepted the patch.</p>
|
|
|
|
<p>The following are recommended to avoid this problem:
|
|
<ol>
|
|
<li>Set the org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES
|
|
system property to false.</li>
|
|
<li>Apply the patch from bug <a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=40212">40212</a>
|
|
or upgrade to a version that has that patch applied.</li>
|
|
<li>Upgrade to log4j 1.2.16 or later to better defend against class loader attack
|
|
or provide a better diagnostic message when it does occur.</li>
|
|
</ol>
|
|
</p>
|
|
|
|
<p>It is impossible for log4j to defend against all attacks on
|
|
its internal state by a class loader. There is a limit to
|
|
the defensive measures that will be incorporated.</p>
|
|
|
|
<p>For more background, see bugs
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=40212">40212</a>,
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=41939">41939</a>,
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=43867">43867</a>,
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=40159">40159</a>,
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=43181">43181</a>,
|
|
<a href="http://issues.apache.org/bugzilla/show_bug.cgi?id=41316">41316</a> and
|
|
<a href="https://issues.apache.org/bugzilla/show_bug.cgi?id=37956">37956</a>.
|
|
</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="rfa">Why isn't my rolling file appender properly rolling files or why does
|
|
logging events get written to the old log file?</a></dt>
|
|
<dd>Most commonly this is due to multiple appenders attempting to
|
|
use the same file path and most likely by having multiple independent
|
|
instances of log4j read the same configuration file, however having the log file
|
|
open by another process (an editor, backup utility) can also interfere with rolling.
|
|
No provided file appender is reliable when multiple instances are writing to
|
|
the same file path and java.io provides no mechanism to coordinate writing
|
|
between JVM's.<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="noconfig">
|
|
Why do I see a warning about "No appenders found for logger" and
|
|
"Please configure log4j properly"?
|
|
</a></dt>
|
|
<dd>
|
|
This occurs when the default configuration files log4j.properties and
|
|
log4j.xml can not be found and the application performs no explicit configuration.
|
|
log4j uses Thread.getContextClassLoader().getResource() to locate the default
|
|
configuration files and does not directly check the file system.
|
|
Knowing the appropriate location to place log4j.properties or log4j.xml
|
|
requires understanding the search strategy of the class loader in use.
|
|
log4j does not provide a default configuration since output to the console
|
|
or to the file system may be prohibited in some environments. Also see
|
|
<a href="#a3.5">FAQ: Why can't log4j find my properties in a J2EE or WAR application?</a>.
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table><hr />
|
|
</dd>
|
|
<dt><a name="sysprops">What system properties are checked by log4j?</a></dt>
|
|
<dd>
|
|
<dl>
|
|
<dt>log4j.debug</dt>
|
|
<dd>If true, log4j will output internal debugging messages to the console.</dd>
|
|
<dt>log4j.defaultInitOverride</dt>
|
|
<dd>If true, log4j will not perform default initialization,
|
|
that is check for log4j.properties or log4j.xml, at the first logging request.</dd>
|
|
<dt>log4j.configuration</dt>
|
|
<dd>URL for default initialization configuration file.</dd>
|
|
<dt>log4j.configurationClass</dt>
|
|
<dd>Class name for configurator to process default initialization configuration file.</dd>
|
|
<dt>log4j.ignoreTCL</dt>
|
|
<dd>If true, the thread class loader will be ignored when loading classes.</dd>
|
|
</dl>
|
|
<p>The SMTPAppender may be influenced by mail.smtp and mail.smtps system properties.</p>
|
|
<table border="0"><tr><td align="right"><a href="#top">[top]</a></td></tr></table></dd>
|
|
</dl>
|
|
|
|
</div>
|
|
</div>
|
|
<div class="clear">
|
|
<hr/>
|
|
</div>
|
|
<div id="footer">
|
|
<div class="xright">©
|
|
1999-2010
|
|
|
|
Apache Software Foundation
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
</div>
|
|
<div class="clear">
|
|
<hr/>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|