How to use current date pattern in log4j2 fileName?

Question

<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
    <Properties>
        <property name="filePattern">%d{yyyy-MM-dd}</property>
    </Properties>
    <Appenders>
        <RollingFile name="TEST" fileName="application-${filePattern}.log" filePattern="application-${filePattern}-rolled.log">
            <Policies>
                <TimeBasedTriggeringPolicy modulate="true"/>
            </Policies>
        </RollingFile>
    </Appenders>
    //...
</Configuration>

I'd like to use the current date directly in the written logfile. But the result of the configuration above is application-%{yyyy-MM-dd} as filename.

Why is the date placeholder not resolved? By the way: the renamed file on midnight is properly renamed like application-2016-03-13-rolled.log . Why does it work there, but not in the current logfile?

I'm running tomcat 8 and java 8 , if that matters.

Answer 1

这个工作（为什么）：

<property name="filePattern">${date:yyyy-MM-dd}</property>

Answer 2

Remove the filename attribute. It worked for me. (got the solution from: https://issues.apache.org/jira/browse/LOG4J2-1859 ) Here is my working configuration

    <RollingFile name="File" filePattern="${basePath}/api_test_execution_log_%d{yyyy-MM-dd}_%d{HH-mm-ss}_%i.log" immediateFlush="true">
       <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>

       <Policies>
            <TimeBasedTriggeringPolicy interval="1" modulate="true"/>
            <SizeBasedTriggeringPolicy size="32 MB" />
            <OnStartupTriggeringPolicy/>
       </Policies>
    </RollingFile>

Answer 3

I don't know why the placeholder isn't resolved but here is my working configuration:

  <Appenders>
    <RollingFile 
        name="Permament" 
        fileName="E:/workspace/myproject/logs/ergo.log"
        filePattern="E:/workspace/myproject/logs/ergo.%d{yyyy-MM-dd.HH:mm}.log"
        immediateFlush="true">
        <PatternLayout pattern="%d{HH:mm:ss.SSS} %5p{length=5} - %c{1} %m %ex%n"/>
        <Policies>
            <TimeBasedTriggeringPolicy/>
        </Policies>
    </RollingFile>

Answer 4

For those are using Log4j2 version 2.6.2 and below:

The fileName is indeed a file name that never changes while the application is running. If you do not want this behavior upgrade to the latest version of Log4j 2 and do not specify the fileName attribute.

From https://issues.apache.org/jira/browse/LOG4J2-1859