Logger configuration using Log4j2

Question

I am using Log4j in spring-boot app because I needed automatic configuration reloading. I am able to configure it and automatic configuration is working fine. BUT the problem is I want to create single log4j2.properties file where same logs can be written to console and log.file . I have tried my hand with it but no luck. Here is the sample file which writes logs to console.

name=PropertiesConfig
property.filename = appLogger
appenders = console, file
monitorInterval=10

appender.console.type = Console
appender.console.name = STDOUT
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

appender.file.type = File
appender.file.name = LOGFILE
appender.file.fileName=.\\logs\\appLogger.log
appender.file.layout.type=PatternLayout
appender.file.layout.pattern=[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

rootLogger.level = INFO
rootLogger.appenderRefs = stdout,LOGFILE
rootLogger.appenderRef.stdout.ref = STDOUT

Answer 1

If you are not limited to using .properties and can use .yaml then here is a working example.

Configutation:
  name: Default

  Properties:
    Property:
      name: log-path
      value: "/var/log/service"

  Appenders:
    #Appender will write the logs to console
    Console:
      name: Console_append
      target: SYSTEM_OUT
      PatternLayout:
        pattern: "%highlight{[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n}{FATAL=red blink, ERROR=red, WARN=yellow bold, INFO=blue, DEBUG=green bold, TRACE=black}"
    #Appender will write the logs to File
    File:
      name: file_append
      fileName: ${log-path}/service.log
      PatternLayout:
        pattern: "%highlight{[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n}{FATAL=red blink, ERROR=red, WARN=yellow bold, INFO=blue, DEBUG=green bold, TRACE=black}"
    #Appender will write the logs to rolling file
    RollingFile:
      - name: Roll_file_append
        fileName: ${log-path}/service-rolling.log
        filePattern: "${log-path}/service.log.%d{yyyy-MM-dd-hh-mm}.gz"
        PatternLayout:
          pattern: "[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n"
        Policies:
        #Roll the log file and zip if if the size exceeds 1MB
          SizeBasedTriggeringPolicy:
            size: 1 MB
        #Keep below defined number of rolling files before deleting them
        DefaultRollOverStrategy:
          max: 45

  Loggers:
      #Root logging level for application
      Root:
        level: info
        AppenderRef:
          - ref: Console_append
          - ref: file_append
      #Application specific logging
      Logger:
        - name: com.system.serivce
          additivity: false
          level: debug
          AppenderRef:
            - ref: Console_append
            - ref: file_append
            - ref: Roll_file_append

Reference: here

Note: you need to include jackson-dataformat-yaml and jackson-databind at the class path for yaml to work.

Answer 2

This will help you to write the logs on console as well as in E2Elog.txt file.

log4j.rootLogger=INFO,CONSOLE,LOGFILE,TESTAPPENDER

log4j.appender.TESTAPPENDER=com.automate.commonUtils.TestNGReportAppender
        log4j.appender.TESTAPPENDER.layout=org.apache.log4j.PatternLayout
        log4j.appender.TESTAPPENDER.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%

        log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
        log4j.appender.CONSOLE.Follow=true
        log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
        log4j.appender.CONSOLE.layout.ConversionPattern=%-4r [%t] %-5p %c %x \u2013 %m%n

        log4j.appender.LOGFILE=org.apache.log4j.DailyRollingFileAppender
        log4j.appender.LOGFILE.File=E2Elog.txt
        log4j.appender.LOGFILE.DatePattern='.'yyyy-MM-dd
        log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
        log4j.appender.LOGFILE.layout.ConversionPattern=%d{dd-MM-yyyy HH:mm:ss} %m%n

Apart from this you have to add below code also.

package com.automate.commonUtils;
import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Layout;
import org.apache.log4j.spi.LoggingEvent;
import org.testng.Reporter;

public class TestNGReportAppender extends AppenderSkeleton {

     @Override
      protected void append(final LoggingEvent event) {
        Reporter.log(eventToString(event));
      }

      private String eventToString(final LoggingEvent event) {
        final StringBuilder result = new StringBuilder(layout.format(event));

        if(layout.ignoresThrowable()) {
          final String[] s = event.getThrowableStrRep();
          if (s != null) {
            for (final String value : s) {
              result.append(value).append(Layout.LINE_SEP);
            }
          }
        }
        return result.toString();
      }

      @Override
      public void close() {

      }

      @Override
      public boolean requiresLayout() {
        return true;
      }



}

Hope this will work :)

Answer 3

Add rootLogger.appenderRef.file.ref = LOGFILE to the bottom of your configuration file.

Actually, I prefer using .xml instead of .properties , because I think .xml is more user-friendly.

EG

<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
    <Appenders>
        <Console name="STDOUT" target="SYSTEM_OUT">
            <PatternLayout pattern="%m%n"/>
        </Console>
        <File name="MyFile" fileName="logs/app.log">
            <PatternLayout>
                <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>
            </PatternLayout>
        </File>
    </Appenders>

    <Loggers>
        <Root level="INFO">
            <AppenderRef ref="STDOUT"/>
            <AppenderRef ref="MyFile"/>
        </Root>
    </Loggers>
</Configuration>