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| <document xmlns="http://maven.apache.org/XDOC/2.0" |
| xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" |
| xsi:schemaLocation="http://maven.apache.org/XDOC/2.0 http://maven.apache.org/xsd/xdoc-2.0.xsd"> |
| <properties> |
| <title>Migrating from Log4j 1.x</title> |
| <author email="rgoers@apache.org">Ralph Goers</author> |
| </properties> |
| |
| <body> |
| <section name="Migrating from Log4j 1.x"> |
| <a name="Log4j1.2Bridge"/> |
| <subsection name="Using the Log4j 1.x bridge"> |
| <p> |
| Perhaps the simplest way to convert to using Log4j 2 is to replace the log4j 1.x jar file with |
| Log4j 2's <code>log4j-1.2-api.jar</code>. However, to use this successfully applications must meet the |
| following requirements: |
| </p> |
| <ol> |
| <li>They must not access methods and classes internal to the Log4j 1.x implementation such |
| as <code>Appender</code>s, <code>LoggerRepository</code> or <code>Category</code>'s |
| <code>callAppenders</code> method.</li> |
| <li>They must not programmatically configure Log4j.</li> |
| <li>They must not configure by calling the classes <code>DOMConfigurator</code> or |
| <code>PropertyConfigurator</code>.</li> |
| </ol> |
| </subsection> |
| <subsection name="Converting to the Log4j 2 API"> |
| <p>For the most part, converting from the Log4j 1.x API to Log4j 2 should be fairly simple. Many |
| of the log statements will require no modification. However, where necessary the following changes must be |
| made.</p> |
| <ol> |
| <li> |
| The main package in version 1 is <code>org.apache.log4j</code>, in version 2 it is |
| <code>org.apache.logging.log4j</code> |
| </li> |
| <li> |
| Calls to <code>org.apache.log4j.Logger.getLogger()</code> must be modified to |
| <code>org.apache.logging.log4j.LogManager.getLogger()</code>. |
| </li> |
| <li> |
| Calls to <code>org.apache.log4j.Logger.getRootLogger()</code> or |
| <code>org.apache.log4j.LogManager.getRootLogger()</code> must be replaced with |
| <code>org.apache.logging.log4j.LogManager.getRootLogger()</code>.</li> |
| <li> |
| Calls to <code>org.apache.log4j.Logger.getLogger</code> that accept a <code>LoggerFactory</code> must |
| remove the <code>org.apache.log4j.spi.LoggerFactory</code> and use one of Log4j 2's other extension |
| mechanisms. |
| </li> |
| <li> |
| Replace calls to <code>org.apache.log4j.Logger.getEffectiveLevel()</code> with |
| <code>org.apache.logging.log4j.Logger.getLevel()</code>. |
| </li> |
| <li> |
| Remove calls to <code>org.apache.log4j.LogManager.shutdown()</code>, they are not needed in version 2 |
| because the Log4j Core now automatically adds a JVM shutdown hook on start up to perform any Core |
| clean ups. |
| <ol> |
| <li> |
| Starting in Log4j 2.1, you can specify a custom |
| <a class="javadoc" href="../log4j-core/apidocs/org/apache/logging/log4j/core/util/ShutdownCallbackRegistry.html">ShutdownCallbackRegistry</a> |
| to override the default JVM shutdown hook strategy. |
| </li> |
| <li> |
| Starting in Log4j 2.6, you can now use <code>org.apache.logging.log4j.LogManager.shutdown()</code> |
| to initiate shutdown manually. |
| </li> |
| </ol> |
| </li> |
| <li> |
| Calls to <code>org.apache.log4j.Logger.setLevel()</code> or similar methods are not supported in the API. |
| Applications should remove these. Equivalent functionality is provided in the Log4j 2 implementation |
| classes, see <code>org.apache.logging.log4j.core.config.Configurator.setLevel()</code>, but may leave |
| the application susceptible to changes in Log4j 2 internals. |
| </li> |
| <li> |
| Where appropriate, applications should convert to use parameterized messages instead of String |
| concatenation. |
| </li> |
| <li> |
| <a href="http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/MDC.html"><code>org.apache.log4j.MDC</code></a> and |
| <a href="http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/NDC.html"><code>org.apache.log4j.NDC</code></a> |
| have been replaced by the <a href="thread-context.html">Thread Context</a>. |
| </li> |
| </ol> |
| </subsection> |
| <subsection name="Configuring Log4j 2"> |
| <p> |
| Although the Log4j 2 configuration syntax is different than that of Log4j 1.x, most, if not all, of |
| the same functionality is available. |
| </p> |
| <p> |
| Note that system property interpolation via the <code>${foo}</code> syntax has been extended to allow |
| property lookups from many different sources. See the <a href="lookups.html">Lookups</a> documentation |
| for more details. For example, using a lookup for the system property named <code>catalina.base</code>, |
| in Log4j 1.x, the syntax would be <code>${catalina.base}</code>. In Log4j 2, the syntax would be |
| <code>${sys:catalina.base}</code>. |
| </p> |
| <p> |
| Log4j 1.x has a XMLLayout which is different from the XmlLayout in Log4j 2, the log4j-1.2-api module |
| contains a <code>Log4j1XmlLayout</code> which produce output in the format as in Log4j 1.x. |
| The Log4j 1.x <code>SimpleLayout</code> can be emulated with PatternLayout "%level - %m%n". |
| The Log4j 1.x <code>TTCCLayout</code> can be emulated with PatternLayout "%r [%t] %p %c %notEmpty{%ndc }- %m%n". |
| </p> |
| <p> |
| Both <code>PatternLayout</code> and <code>EnhancedPatternLayout</code> in Log4j 1.x can be replaced with |
| <code>PatternLayout</code> in Log4j 2. The log4j-1.2-api module contains two pattern conversions "%ndc" and "%properties" which |
| can be used to emulate "%x" and "%X" in Log4j 1.x PatternLayout ("%x" and %X" in Log4j 2 have a slightly different format). |
| </p> |
| <p> |
| Below are the example configurations for Log4j 1.x and their counterparts in Log4j 2. |
| </p> |
| |
| <h4>Sample 1 - Simple configuration using a Console Appender</h4> |
| <p>Log4j 1.x XML configuration</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd"> |
| <log4j:configuration xmlns:log4j='http://jakarta.apache.org/log4j/'> |
| <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender"> |
| <layout class="org.apache.log4j.PatternLayout"> |
| <param name="ConversionPattern" value="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </layout> |
| </appender> |
| <category name="org.apache.log4j.xml"> |
| <priority value="info" /> |
| </category> |
| <Root> |
| <priority value ="debug" /> |
| <appender-ref ref="STDOUT" /> |
| </Root> |
| </log4j:configuration>]]></pre> |
| <p>Log4j 2 XML configuration</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <Configuration> |
| <Appenders> |
| <Console name="STDOUT" target="SYSTEM_OUT"> |
| <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </Console> |
| </Appenders> |
| <Loggers> |
| <Logger name="org.apache.log4j.xml" level="info"/> |
| <Root level="debug"> |
| <AppenderRef ref="STDOUT"/> |
| </Root> |
| </Loggers> |
| </Configuration>]]></pre> |
| |
| <h4>Sample 2 - Simple configuration using a File Appender, XMLLayout and SimpleLayout</h4> |
| <p>Log4j 1.x XML configuration</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd"> |
| <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> |
| <appender name="A1" class="org.apache.log4j.FileAppender"> |
| <param name="File" value="A1.log" /> |
| <param name="Append" value="false" /> |
| <layout class="org.apache.log4j.xml.XMLLayout" /> |
| </appender> |
| <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender"> |
| <layout class="org.apache.log4j.SimpleLayout" /> |
| </appender> |
| <category name="org.apache.log4j.xml"> |
| <priority value="debug" /> |
| <appender-ref ref="A1" /> |
| </category> |
| <root> |
| <priority value ="debug" /> |
| <appender-ref ref="STDOUT" /> |
| </Root> |
| </log4j:configuration>]]></pre> |
| |
| <p>Log4j 2 XML configuration</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <Configuration> |
| <Appenders> |
| <File name="A1" fileName="A1.log" append="false"> |
| <Log4j1XmlLayout /> |
| </File> |
| <Console name="STDOUT" target="SYSTEM_OUT"> |
| <PatternLayout pattern="%level - %m%n"/> |
| </Console> |
| </Appenders> |
| <Loggers> |
| <Logger name="org.apache.log4j.xml" level="debug"> |
| <AppenderRef ref="A1"/> |
| </Logger> |
| <Root level="debug"> |
| <AppenderRef ref="STDOUT"/> |
| </Root> |
| </Loggers> |
| </Configuration>]]></pre> |
| |
| <h4>Sample 3 - SocketAppender</h4> |
| <p>Log4j 1.x XML configuration. This example from Log4j 1.x is misleading. The SocketAppender does not |
| actually use a Layout. Configuring one will have no effect.</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd"> |
| <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> |
| <appender name="A1" class="org.apache.log4j.net.SocketAppender"> |
| <param name="RemoteHost" value="localhost"/> |
| <param name="Port" value="5000"/> |
| <param name="LocationInfo" value="true"/> |
| <layout class="org.apache.log4j.PatternLayout"> |
| <param name="ConversionPattern" value="%t %-5p %c{2} - %m%n"/> |
| </layout> |
| </appender> |
| <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender"> |
| <layout class="org.apache.log4j.PatternLayout"> |
| <param name="ConversionPattern" value="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </layout> |
| </appender> |
| <category name="org.apache.log4j.xml"> |
| <priority value="debug"/> |
| <appender-ref ref="A1"/> |
| </category> |
| <root> |
| <priority value="debug"/> |
| <appender-ref ref="STDOUT"/> |
| </Root> |
| </log4j:configuration>]]></pre> |
| |
| <p>Log4j 2 XML configuration</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <Configuration> |
| <Appenders> |
| <Socket name="A1" host="localHost" port="5000"> |
| <PatternLayout pattern="%t %-5p %c{2} - %m%n"/> |
| </Socket> |
| <Console name="STDOUT" target="SYSTEM_OUT"> |
| <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </Console> |
| </Appenders> |
| <Loggers> |
| <Logger name="org.apache.log4j.xml" level="debug"> |
| <AppenderRef ref="A1"/> |
| </Logger> |
| <Root level="debug"> |
| <AppenderRef ref="STDOUT"/> |
| </Root> |
| </Loggers> |
| </Configuration>]]></pre> |
| |
| <h4>Sample 4 - AsyncAppender and TTCCLayout</h4> |
| <p>Log4j 1.x XML configuration using the AsyncAppender.</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd"> |
| <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" configDebug="true"> |
| <appender name="ASYNC" class="org.apache.log4j.AsyncAppender"> |
| <appender-ref ref="TEMP"/> |
| </appender> |
| <appender name="TEMP" class="org.apache.log4j.FileAppender"> |
| <param name="File" value="temp"/> |
| <layout class="org.apache.log4j.TTCCLayout"> |
| <param name="ThreadPrinting" value="true"/> |
| <param name="CategoryPrefixing" value="true"/> |
| <param name="ContextPrinting" value="true"/> |
| </layout> |
| </appender> |
| <root> |
| <priority value="debug"/> |
| <appender-ref ref="ASYNC"/> |
| </Root> |
| </log4j:configuration>]]></pre> |
| |
| <p>Log4j 2 XML configuration. </p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <Configuration status="debug"> |
| <Appenders> |
| <File name="TEMP" fileName="temp"> |
| <PatternLayout pattern="%r [%t] %p %c %notEmpty{%ndc }- %m%n"/> |
| </File> |
| <Async name="ASYNC"> |
| <AppenderRef ref="TEMP"/> |
| </Async> |
| </Appenders> |
| <Loggers> |
| <Root level="debug"> |
| <AppenderRef ref="ASYNC"/> |
| </Root> |
| </Loggers> |
| </Configuration>]]></pre> |
| |
| |
| <h4>Sample 5 - AsyncAppender with Console and File</h4> |
| <p>Log4j 1.x XML configuration using the AsyncAppender.</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <!DOCTYPE log4j:configuration PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd"> |
| <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/" configDebug="true"> |
| <appender name="ASYNC" class="org.apache.log4j.AsyncAppender"> |
| <appender-ref ref="TEMP"/> |
| <appender-ref ref="CONSOLE"/> |
| </appender> |
| <appender name="CONSOLE" class="org.apache.log4j.ConsoleAppender"> |
| <layout class="org.apache.log4j.PatternLayout"> |
| <param name="ConversionPattern" value="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </layout> |
| </appender> |
| <appender name="TEMP" class="org.apache.log4j.FileAppender"> |
| <param name="File" value="temp"/> |
| <layout class="org.apache.log4j.PatternLayout"> |
| <param name="ConversionPattern" value="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </layout> |
| </appender> |
| <root> |
| <priority value="debug"/> |
| <appender-ref ref="ASYNC"/> |
| </Root> |
| </log4j:configuration>]]></pre> |
| |
| <p>Log4j 2 XML configuration. Note that the Async Appender should be configured after the appenders it |
| references. This will allow it to shutdown properly.</p> |
| <pre class="prettyprint linenums"><![CDATA[<?xml version="1.0" encoding="UTF-8"?> |
| <Configuration status="debug"> |
| <Appenders> |
| <Console name="CONSOLE" target="SYSTEM_OUT"> |
| <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </Console> |
| <File name="TEMP" fileName="temp"> |
| <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/> |
| </File> |
| <Async name="ASYNC"> |
| <AppenderRef ref="TEMP"/> |
| <AppenderRef ref="CONSOLE"/> |
| </Async> |
| </Appenders> |
| <Loggers> |
| <Root level="debug"> |
| <AppenderRef ref="ASYNC"/> |
| </Root> |
| </Loggers> |
| </Configuration>]]></pre> |
| </subsection> |
| </section> |
| </body> |
| </document> |