Related
I have put log4j to my buildpath, but I get the following message when I run my application:
log4j:WARN No appenders could be found for logger (dao.hsqlmanager).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
What do these warnings mean? Whats the appender here?
This Short introduction to log4j guide is a little bit old but still valid.
That guide will give you some information about how to use loggers and appenders.
Just to get you going you have two simple approaches you can take.
First one is to just add this line to your main method:
BasicConfigurator.configure();
Second approach is to add this standard log4j.properties (taken from the above mentioned guide) file to your classpath:
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
It looks like you need to add the location of your log4j.properties file to the Classpath in Eclipse.
Make sure your project is open in Eclipse, then click on the "Run" menu at the top of Eclipse and click on the following:
Run
Run Configurations
Classpath (tab)
User Entries
Advanced (button on the right)
Add Folders
then navigate to the folder that contains your log4j.properties file
Apply
Run
The error message should no longer appear.
Quick solution:
add code to main function:
String log4jConfPath = "/path/to/log4j.properties";
PropertyConfigurator.configure(log4jConfPath);
create a file named log4j.properties at /path/to
log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
This is just a warning.
Fixing
This occurs when the default configuration files log4j.properties and log4j.xml can not be found and the application performs no explicit configuration.
To fix that, simply create/copy log4j.properties or log4j.xml into your a location on the classpath (usually the same as the jar files).
Optionally set java option: -Dlog4j.configuration=file:///path/to/log4j.properties.
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.
Debugging
For debugging, you may try to use -Dlog4j.debug=true parameter.
Configuration of log4j.properties
Sample configuration of log4j.properties:
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
# Print only messages of level WARN or above in the package com.foo.
log4j.logger.com.foo=WARN
Here is another configuration file that uses multiple appenders:
log4j.rootLogger=debug, stdout, R
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=example.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n
Apache Solr
If using Solr, copy <solr>/example/resources/log4j.properties into a location on the classpath.
Sample configuration of log4j.properties from Solr goes like:
# Logging level
solr.log=logs/
log4j.rootLogger=INFO, file, CONSOLE
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-4r [%t] %-5p %c %x \u2013 %m%n
#- size rotation with log cleanup.
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.MaxFileSize=4MB
log4j.appender.file.MaxBackupIndex=9
#- File to log to and log format
log4j.appender.file.File=${solr.log}/solr.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %C; %m\n
log4j.logger.org.apache.zookeeper=WARN
log4j.logger.org.apache.hadoop=WARN
# set to INFO to enable infostream log messages
log4j.logger.org.apache.solr.update.LoggingInfoStream=OFF
See also:
Short introduction to log4j: Default Initialization Procedure
Why can't log4j find my properties in a J2EE or WAR application?
Most of the answers here suggested that log4j.properties file be placed in the right location(for maven project, it should be located in src/main/resources)
But for me, the problem is that my log4j.properties is not correctly configured. Here's a sample that works for me, you can try it out first.
# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
As explained earlier there are 2 approaches
First one is to just add this line to your main method:
BasicConfigurator.configure();
Second approach is to add this standard log4j.properties file to your classpath:
While taking second approach you need to make sure you initialize the file properly,
Eg.
Properties props = new Properties();
props.load(new FileInputStream("log4j property file path"));
props.setProperty("log4j.appender.File.File", "Folder where you want to store log files/" + "File Name");
Make sure you create required folder to store log files.
You use the Logger in your code to log a message. The Appender is a Object appended to a Logger to write the message to a specific target. There are FileAppender to write to text-files or the ConsoleAppender to write to the Console. You need to show your code of the Logger and Appender setup for more help.
please read the tutorial for a better understanding of the interaction of Logger and Appender.
Make sure the properties file has properly set.
And again, it seems like that the compiler cannot find the properties file, you can set as follow at the pom (only when you use maven project).
<build>
<sourceDirectory> src/main/java</sourceDirectory>
<testSourceDirectory> src/test/java</testSourceDirectory>
<resources>
<resource>
<directory>resources</directory>
</resource>
</resources>
</build >
I get the same error. Here the problem which leads to this error message:
I create some objects which use the Logger before I configure the log4j:
Logger.getLogger(Lang.class.getName()).debug("Loading language: " + filename);
Solution:
Configure the log4j at the beginning in the main method:
PropertyConfigurator.configure(xmlLog4JConfigFile);
// or BasicConfigurator.configure(); if you dont have a config file
Add the following as the first code:
Properties prop = new Properties();
prop.setProperty("log4j.rootLogger", "WARN");
PropertyConfigurator.configure(prop);
I faced the same issue when I tried to run the JUnit test class.
The issue is resolved after I manually added the log4j.properties file in the src/test/resources folder.
Adding the below code to the log4j.properties file solved the issue:
# Root logger option
log4j.rootLogger=INFO, file, stdout
# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=C:\\logging.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
I think you should understand where the log4j jar file or the Java code looks for the log4j configuration files.
src/main/resources/log4j.properties is Eclipse path.
Place them in a proper location so that you don't have to hard code the absolute path in code.
Read my article and sample solution for that
https://askyourquestions.info/how-to-see-where-the-log-is-logger-in-slf4j/
First of all: Create a log4j.properties file
# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
Place it in src/main/resources/
After that, use this 2 dependencies:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.5</version>
</dependency>
It is necessary to add this final dependency to POM file:
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.1.5.RELEASE</version>
</dependency>
In my case, the error was the flag "additivity". If it's "false" for you root project package, then the child packages will not have an appender and you will see the "appender not found" error.
Another reason this may happen (in RCP4) is that you are using multiple logging frameworks in your target file. As an example, this will occur if you use a combination of slf4j, log4j and ch.qos.logback.slf4j in your target files content tab.
If you are using Eclipse and this problem appeared out of nowhere after everything worked fine beforehand, try going to Project - Clean - Clean.
I ran into this issue when trying to build an executable jar with maven in intellij 12. It turned out that because the java manifest file didn't include a class path the log4j properties file couldn't be found at the root level (where the jar file was executed from.)
FYI I was getting the logger like this:
Logger log = LogManager.getLogger(MyClassIWantedToLogFrom.class);
And I was able to get it to work with a pom file that included this:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-5</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.mycompany.mainPackage.mainClass</mainClass>
</manifest>
<manifestEntries>
<Class-Path>.</Class-Path> <!-- need to add current directory to classpath properties files can be found -->
</manifestEntries>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
Make sure your project is open in Eclipse, then click on the "Run" menu at the top of Eclipse and click on the following:
Run
Run Configurations
Classpath (tab)
User Entries
add jar on the right
add log4j jar file
Apply
Run
The error message should no longer appear.
The reason can be lack of the word static in some:
final static Logger logging = Logger.getLogger(ProcessorTest.class);
If I make logger the instance field, I am getting exactly this very warning:
No appenders could be found for logger (org.apache.kafka.producer.Sender)
What is worse, the warning points not to ProcessorTest, where the mistake lives, but to an absolutely different class (Sender) as a source of problems. That class has correct set logger and need not any changes! We could look for the problem for ages!
I faced the same problem when I use log4j2. My problem is caused by using wrong dependent library:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<scope>runtime</scope>
</dependency>
Instead, I should use:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<scope>runtime</scope>
</dependency>
In my case, I have a log4j2.xml defined in my "resources" directory, and specified to use it by:
System.setProperty("log4j.configurationFile", "log4j2.xml");
Log4J display this warning message when Log4j Java code is searching to create a first log line in your program.
At this moment, Log4j make 2 things
it search to find log4j.properties file
it search to instantiate the appender define in log4j.properties
If log4J doesn't find log4j.properties file or if appender declared in log4j.rootlogger are not defined elsewhere in log4j.properties file the warning message is displayed.
CAUTION: the content of Properties file must be correct.
The following content is NOT correct
log4j.rootLogger=file
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=c:/Trace/MsgStackLogging.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%m%n
log4j.appender.FILE.ImmediateFlush=true
log4j.appender.FILE.Threshold=debug
log4j.appender.FILE.Append=false
because file appender is declared in LOWER-CASE in log4j.rootlogger statement and defined in log4j.appender statement using UPPER-CASE !
A correct file would be
log4j.rootLogger=FILE
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=c:/Trace/MsgStackLogging.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%m%n
log4j.appender.FILE.ImmediateFlush=true
log4j.appender.FILE.Threshold=debug
log4j.appender.FILE.Append=false
If MAVEN is used, you must put log4j.properties files in src/main/resources AND start a MAVEN build.
Log4j.properties file is then copied in target/classes folder.
Log4J use the log4j.properties file that it found in target/classes !
I had this problem too.
I just forgot to mark the resources directory in IntelliJ IDEA
Rightclick on your directory
Mark directory as
Resources root
For me, the reason was apparently different, and the error message misleading.
With just this in my build.gradle, it would complain that slf4j was missing at the beginning of the log, but still log things, albeit in a poor format:
compile 'log4j:log4j:1.2.17'
Adding that dependency would cause the discussed "no appenders could be found" error message for me, even though I had defined them in src/main/java/log4j.properties:
compile 'log4j:log4j:1.2.17'
compile 'org.slf4j:slf4j-log4j12:1.7.25'
Finally, adding the following dependency (which I only guessed at by copycatting it from another project) resolved the issue:
compile 'log4j:log4j:1.2.17'
compile 'org.slf4j:slf4j-log4j12:1.7.25'
compile 'commons-logging:commons-logging:1.2'
I don't know why, but with this it works. Any insights on that?
My Eclipse installation could not find log4j.properties when running JUnit tests from Eclipse, even though the file was located at src/test/resources.
The reason was that Eclipse (or the m2e connector) did not copy content from src/test/resources to the expected output folder target/test-classes - the root cause was that in the project's properties under Java Build Path -> Source tab -> Source folders on build path -> src/test/resources, somehow there was an Excluded: ** entry. I removed that excluded entry.
Alternatively, I could have manually copied src/test/resources/log4j.properties to target/test-classes/log4j.properties.
If log4j.properties is indeed on the classpath, you are using Spring Boot to make a WAR file for deployment to an app server, you are omitting a web.xml file in favour of Spring Boot's autoconfigure, and you are not getting any log messages whatsoever, you need to explicitly configure Log4j. Assuming you are using Log4j 1.2.x:
public class AppConfig extends SpringBootServletInitializer {
public static void main( String[] args ) {
// Launch the application
ConfigurableApplicationContext context = SpringApplication.run( AppConfig.class, args );
}
#Override
protected SpringApplicationBuilder configure( SpringApplicationBuilder application ) {
InputStream log4j = this.getClass().getClassLoader().getResourceAsStream("log4j.properties");
PropertyConfigurator.configure(log4j);
return application;
}
// Other beans as required...
}
Maybe add the relevent project contains log4j in java build path, I add mahout_h2o into it when I met this problem in a mahout project using eclipse, it works!
if you work together with a lot of projects you may face a style problem.
*you have to have one lof4j.properties file and this file is included log properties of other project.
*Beside you can try to put log4j properties files into src path when the project is worked Linux OS, libs of other project and log4.properties files can be under one folder into a location on the classpath.
First import:
import org.apache.log4j.PropertyConfigurator;
Then add below code to main method:
String log4jConfPath ="path to/log4j.properties";
PropertyConfigurator.configure(log4jConfPath);
Create a file at path to and add the below code to that file.
log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
The solution on this site worked for me https://crunchify.com/java-how-to-configure-log4j-logger-property-correctly/. I now see no warnings at all from log4j
I put this in a log4j.properties file that I put in src/main/resources
# This sets the global logging level and specifies the appenders
log4j.rootLogger=INFO, theConsoleAppender
# settings for the console appender
log4j.appender.theConsoleAppender=org.apache.log4j.ConsoleAppender
log4j.appender.theConsoleAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.theConsoleAppender.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
Consider the log4j JVM argument Dlog4j.configuration
In general:
Add the JVM argument that points out the log4j config file.
The syntax is just like follows:
java [ options ] -jar file.jar [ arguments ]
A sample of a real command line is just like the following:
java -Dlog4j.configuration=conf/log4j.xml -jar myJarFile.jar myArg1 myArg2
For IntelliJ IDE users:
1.Run/Debug Configurations
2.Edit configurations...
3.VM options
4.Enter the same value also starting with "-D"
Tips:
1.Eclipse IDE users will find an equivalent approach
2.For the run/debug configuration editor, it's very likely that, at the beginning of the times, your particular executable file is not there. Depending on the size of the project you're currently working on, it can be unpleasant to navigate directories to find it. It's less of a hassle if you just run/execute the file (click play) once before proceeding to run/debug config no matter what the execution result is.
3.Pay attention to your working directory, relative paths, and classpath.
I have put log4j to my buildpath, but I get the following message when I run my application:
log4j:WARN No appenders could be found for logger (dao.hsqlmanager).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
What do these warnings mean? Whats the appender here?
This Short introduction to log4j guide is a little bit old but still valid.
That guide will give you some information about how to use loggers and appenders.
Just to get you going you have two simple approaches you can take.
First one is to just add this line to your main method:
BasicConfigurator.configure();
Second approach is to add this standard log4j.properties (taken from the above mentioned guide) file to your classpath:
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
It looks like you need to add the location of your log4j.properties file to the Classpath in Eclipse.
Make sure your project is open in Eclipse, then click on the "Run" menu at the top of Eclipse and click on the following:
Run
Run Configurations
Classpath (tab)
User Entries
Advanced (button on the right)
Add Folders
then navigate to the folder that contains your log4j.properties file
Apply
Run
The error message should no longer appear.
Quick solution:
add code to main function:
String log4jConfPath = "/path/to/log4j.properties";
PropertyConfigurator.configure(log4jConfPath);
create a file named log4j.properties at /path/to
log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
This is just a warning.
Fixing
This occurs when the default configuration files log4j.properties and log4j.xml can not be found and the application performs no explicit configuration.
To fix that, simply create/copy log4j.properties or log4j.xml into your a location on the classpath (usually the same as the jar files).
Optionally set java option: -Dlog4j.configuration=file:///path/to/log4j.properties.
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.
Debugging
For debugging, you may try to use -Dlog4j.debug=true parameter.
Configuration of log4j.properties
Sample configuration of log4j.properties:
# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1
# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender
# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
# Print only messages of level WARN or above in the package com.foo.
log4j.logger.com.foo=WARN
Here is another configuration file that uses multiple appenders:
log4j.rootLogger=debug, stdout, R
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
# Pattern to output the caller's file name and line number.
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] (%F:%L) - %m%n
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=example.log
log4j.appender.R.MaxFileSize=100KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n
Apache Solr
If using Solr, copy <solr>/example/resources/log4j.properties into a location on the classpath.
Sample configuration of log4j.properties from Solr goes like:
# Logging level
solr.log=logs/
log4j.rootLogger=INFO, file, CONSOLE
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-4r [%t] %-5p %c %x \u2013 %m%n
#- size rotation with log cleanup.
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.MaxFileSize=4MB
log4j.appender.file.MaxBackupIndex=9
#- File to log to and log format
log4j.appender.file.File=${solr.log}/solr.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %C; %m\n
log4j.logger.org.apache.zookeeper=WARN
log4j.logger.org.apache.hadoop=WARN
# set to INFO to enable infostream log messages
log4j.logger.org.apache.solr.update.LoggingInfoStream=OFF
See also:
Short introduction to log4j: Default Initialization Procedure
Why can't log4j find my properties in a J2EE or WAR application?
Most of the answers here suggested that log4j.properties file be placed in the right location(for maven project, it should be located in src/main/resources)
But for me, the problem is that my log4j.properties is not correctly configured. Here's a sample that works for me, you can try it out first.
# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
As explained earlier there are 2 approaches
First one is to just add this line to your main method:
BasicConfigurator.configure();
Second approach is to add this standard log4j.properties file to your classpath:
While taking second approach you need to make sure you initialize the file properly,
Eg.
Properties props = new Properties();
props.load(new FileInputStream("log4j property file path"));
props.setProperty("log4j.appender.File.File", "Folder where you want to store log files/" + "File Name");
Make sure you create required folder to store log files.
You use the Logger in your code to log a message. The Appender is a Object appended to a Logger to write the message to a specific target. There are FileAppender to write to text-files or the ConsoleAppender to write to the Console. You need to show your code of the Logger and Appender setup for more help.
please read the tutorial for a better understanding of the interaction of Logger and Appender.
Make sure the properties file has properly set.
And again, it seems like that the compiler cannot find the properties file, you can set as follow at the pom (only when you use maven project).
<build>
<sourceDirectory> src/main/java</sourceDirectory>
<testSourceDirectory> src/test/java</testSourceDirectory>
<resources>
<resource>
<directory>resources</directory>
</resource>
</resources>
</build >
I get the same error. Here the problem which leads to this error message:
I create some objects which use the Logger before I configure the log4j:
Logger.getLogger(Lang.class.getName()).debug("Loading language: " + filename);
Solution:
Configure the log4j at the beginning in the main method:
PropertyConfigurator.configure(xmlLog4JConfigFile);
// or BasicConfigurator.configure(); if you dont have a config file
Add the following as the first code:
Properties prop = new Properties();
prop.setProperty("log4j.rootLogger", "WARN");
PropertyConfigurator.configure(prop);
I faced the same issue when I tried to run the JUnit test class.
The issue is resolved after I manually added the log4j.properties file in the src/test/resources folder.
Adding the below code to the log4j.properties file solved the issue:
# Root logger option
log4j.rootLogger=INFO, file, stdout
# Direct log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=C:\\logging.log
log4j.appender.file.MaxFileSize=10MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
I think you should understand where the log4j jar file or the Java code looks for the log4j configuration files.
src/main/resources/log4j.properties is Eclipse path.
Place them in a proper location so that you don't have to hard code the absolute path in code.
Read my article and sample solution for that
https://askyourquestions.info/how-to-see-where-the-log-is-logger-in-slf4j/
First of all: Create a log4j.properties file
# Root logger option
log4j.rootLogger=INFO, stdout
# Direct log messages to stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
Place it in src/main/resources/
After that, use this 2 dependencies:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.5</version>
</dependency>
It is necessary to add this final dependency to POM file:
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.1.5.RELEASE</version>
</dependency>
In my case, the error was the flag "additivity". If it's "false" for you root project package, then the child packages will not have an appender and you will see the "appender not found" error.
Another reason this may happen (in RCP4) is that you are using multiple logging frameworks in your target file. As an example, this will occur if you use a combination of slf4j, log4j and ch.qos.logback.slf4j in your target files content tab.
If you are using Eclipse and this problem appeared out of nowhere after everything worked fine beforehand, try going to Project - Clean - Clean.
I ran into this issue when trying to build an executable jar with maven in intellij 12. It turned out that because the java manifest file didn't include a class path the log4j properties file couldn't be found at the root level (where the jar file was executed from.)
FYI I was getting the logger like this:
Logger log = LogManager.getLogger(MyClassIWantedToLogFrom.class);
And I was able to get it to work with a pom file that included this:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-5</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.mycompany.mainPackage.mainClass</mainClass>
</manifest>
<manifestEntries>
<Class-Path>.</Class-Path> <!-- need to add current directory to classpath properties files can be found -->
</manifestEntries>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
Make sure your project is open in Eclipse, then click on the "Run" menu at the top of Eclipse and click on the following:
Run
Run Configurations
Classpath (tab)
User Entries
add jar on the right
add log4j jar file
Apply
Run
The error message should no longer appear.
The reason can be lack of the word static in some:
final static Logger logging = Logger.getLogger(ProcessorTest.class);
If I make logger the instance field, I am getting exactly this very warning:
No appenders could be found for logger (org.apache.kafka.producer.Sender)
What is worse, the warning points not to ProcessorTest, where the mistake lives, but to an absolutely different class (Sender) as a source of problems. That class has correct set logger and need not any changes! We could look for the problem for ages!
I faced the same problem when I use log4j2. My problem is caused by using wrong dependent library:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<scope>runtime</scope>
</dependency>
Instead, I should use:
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-slf4j-impl</artifactId>
<scope>runtime</scope>
</dependency>
In my case, I have a log4j2.xml defined in my "resources" directory, and specified to use it by:
System.setProperty("log4j.configurationFile", "log4j2.xml");
Log4J display this warning message when Log4j Java code is searching to create a first log line in your program.
At this moment, Log4j make 2 things
it search to find log4j.properties file
it search to instantiate the appender define in log4j.properties
If log4J doesn't find log4j.properties file or if appender declared in log4j.rootlogger are not defined elsewhere in log4j.properties file the warning message is displayed.
CAUTION: the content of Properties file must be correct.
The following content is NOT correct
log4j.rootLogger=file
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=c:/Trace/MsgStackLogging.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%m%n
log4j.appender.FILE.ImmediateFlush=true
log4j.appender.FILE.Threshold=debug
log4j.appender.FILE.Append=false
because file appender is declared in LOWER-CASE in log4j.rootlogger statement and defined in log4j.appender statement using UPPER-CASE !
A correct file would be
log4j.rootLogger=FILE
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=c:/Trace/MsgStackLogging.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%m%n
log4j.appender.FILE.ImmediateFlush=true
log4j.appender.FILE.Threshold=debug
log4j.appender.FILE.Append=false
If MAVEN is used, you must put log4j.properties files in src/main/resources AND start a MAVEN build.
Log4j.properties file is then copied in target/classes folder.
Log4J use the log4j.properties file that it found in target/classes !
I had this problem too.
I just forgot to mark the resources directory in IntelliJ IDEA
Rightclick on your directory
Mark directory as
Resources root
For me, the reason was apparently different, and the error message misleading.
With just this in my build.gradle, it would complain that slf4j was missing at the beginning of the log, but still log things, albeit in a poor format:
compile 'log4j:log4j:1.2.17'
Adding that dependency would cause the discussed "no appenders could be found" error message for me, even though I had defined them in src/main/java/log4j.properties:
compile 'log4j:log4j:1.2.17'
compile 'org.slf4j:slf4j-log4j12:1.7.25'
Finally, adding the following dependency (which I only guessed at by copycatting it from another project) resolved the issue:
compile 'log4j:log4j:1.2.17'
compile 'org.slf4j:slf4j-log4j12:1.7.25'
compile 'commons-logging:commons-logging:1.2'
I don't know why, but with this it works. Any insights on that?
My Eclipse installation could not find log4j.properties when running JUnit tests from Eclipse, even though the file was located at src/test/resources.
The reason was that Eclipse (or the m2e connector) did not copy content from src/test/resources to the expected output folder target/test-classes - the root cause was that in the project's properties under Java Build Path -> Source tab -> Source folders on build path -> src/test/resources, somehow there was an Excluded: ** entry. I removed that excluded entry.
Alternatively, I could have manually copied src/test/resources/log4j.properties to target/test-classes/log4j.properties.
If log4j.properties is indeed on the classpath, you are using Spring Boot to make a WAR file for deployment to an app server, you are omitting a web.xml file in favour of Spring Boot's autoconfigure, and you are not getting any log messages whatsoever, you need to explicitly configure Log4j. Assuming you are using Log4j 1.2.x:
public class AppConfig extends SpringBootServletInitializer {
public static void main( String[] args ) {
// Launch the application
ConfigurableApplicationContext context = SpringApplication.run( AppConfig.class, args );
}
#Override
protected SpringApplicationBuilder configure( SpringApplicationBuilder application ) {
InputStream log4j = this.getClass().getClassLoader().getResourceAsStream("log4j.properties");
PropertyConfigurator.configure(log4j);
return application;
}
// Other beans as required...
}
Maybe add the relevent project contains log4j in java build path, I add mahout_h2o into it when I met this problem in a mahout project using eclipse, it works!
if you work together with a lot of projects you may face a style problem.
*you have to have one lof4j.properties file and this file is included log properties of other project.
*Beside you can try to put log4j properties files into src path when the project is worked Linux OS, libs of other project and log4.properties files can be under one folder into a location on the classpath.
First import:
import org.apache.log4j.PropertyConfigurator;
Then add below code to main method:
String log4jConfPath ="path to/log4j.properties";
PropertyConfigurator.configure(log4jConfPath);
Create a file at path to and add the below code to that file.
log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yy/MM/dd HH:mm:ss} %p %c{2}: %m%n
The solution on this site worked for me https://crunchify.com/java-how-to-configure-log4j-logger-property-correctly/. I now see no warnings at all from log4j
I put this in a log4j.properties file that I put in src/main/resources
# This sets the global logging level and specifies the appenders
log4j.rootLogger=INFO, theConsoleAppender
# settings for the console appender
log4j.appender.theConsoleAppender=org.apache.log4j.ConsoleAppender
log4j.appender.theConsoleAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.theConsoleAppender.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
Consider the log4j JVM argument Dlog4j.configuration
In general:
Add the JVM argument that points out the log4j config file.
The syntax is just like follows:
java [ options ] -jar file.jar [ arguments ]
A sample of a real command line is just like the following:
java -Dlog4j.configuration=conf/log4j.xml -jar myJarFile.jar myArg1 myArg2
For IntelliJ IDE users:
1.Run/Debug Configurations
2.Edit configurations...
3.VM options
4.Enter the same value also starting with "-D"
Tips:
1.Eclipse IDE users will find an equivalent approach
2.For the run/debug configuration editor, it's very likely that, at the beginning of the times, your particular executable file is not there. Depending on the size of the project you're currently working on, it can be unpleasant to navigate directories to find it. It's less of a hassle if you just run/execute the file (click play) once before proceeding to run/debug config no matter what the execution result is.
3.Pay attention to your working directory, relative paths, and classpath.
Below is my log4j.properties file content, file is placed with the src folder in eclipse.
#Application Logs
log4j.rootlogger=INFO, logg
log4j.appender.logg=org.apache.log4j.RollingFileAppender
log4j.appender.logg.File=D:\\SandhyaFiles\\SeleniumWorkspace\\InterviewProject\\Logs\\Testlogs.log
log4j.appender.logg.layout=org.apache.log4j.PatternLayout
log4j.appender.logg.layout.ConversionPattern=%d -%c -%p - %m%n
log4j.appender.logg.maxFileSize=5MB
log4j.appender.logg.maxBackupIndex=3
Inside Library package i have initialised and used logj as below:
public class Library
{
public static final Logger Log = Logger.getLogger(Library.class);
public void initialized(){
Log.info("Inside initialise")
}}
calling initialize from testcase throws log4j warning:
log4j:WARN No appenders could be found for logger (library.Library).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Please Help me fix this.
It seems like log4j is not able to find the log4j properties file.
One could specify the location of the log4j.properties file explicitly via the log4j.configuration system property.
-Dlog4j.configuration=file:mylogging.properties
In case the system property log4j.configuration is not defined, then the resource is set to its default value log4j.properties and looked for in the classpath of the project (at root).
After so many trials, weirdly re arranging the properties file to this everything is going no warning and could get the logs.
# Root logger option
log4j.rootLogger=INFO, logg
log4j.appender.logg=org.apache.log4j.RollingFileAppender
log4j.appender.logg.File=.\\Logs\\Testlogs.log
log4j.appender.logg.MaxFileSize=5MB
log4j.appender.logg.MaxBackupIndex=3
log4j.appender.logg.layout=org.apache.log4j.PatternLayout
log4j.appender.logg.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
I wonder why this is so? if somebody can explain it will be great help.
Thanks
My log4j properties file
log4j.logger.devpinoyLogger=DEBUG, dest1,
log4j.appender.dest1=org.apache.log4j.RollingFileAppender
log4j.appender.dest1.maxFileSize=5000KB
log4j.appender.dest1.maxBackupIndex=3
log4j.appender.dest1.layout=org.apache.log4j.PatternLayout
log4j.appender.dest1.layout.ConversionPattern=%d{dd/MM/yyyy HH:mm:ss} %c %m%n
log4j.appender.dest1.File=C:\\Selenium\\eclipse-jee-juno-SR1-win32\\eclipse\\Workspace\\Core_Hybrid\\src\\com\\logs\\Application.log
log4j.appender.dest1.Append=false
I get the Error msg as stated below :
log4j:WARN No appenders could be found for logger (org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager).
log4j:WARN Please initialize the log4j system properly.
I have placed my properties files inside the src folder and imported the log4j.jar in the build path.
Please help on this
As I remember the log4j.properties file must be in the root-directory of the execution and added to the classPath. So this means the file must be on the same level as the src-Folder and not within this folder. Or you have to change the root-directory of your execution to your src-folder.
There's a typo in your configuration file. Remove the last ',' in the first line:
log4j.logger.devpinoyLogger=DEBUG, dest1
You should define a root logger to avoid such "No appender" warning.
log4j.rootLogger=DEBUG, dest1
May be it will help:
org.apache.log4j.PropertyConfigurator.configure(log4j.propertiesLocation);
You could add the add part of your package URL and all sub-packages will be printed to the log:
Here is an example:
log4j.logger.org.apache=DEBUG, stdout
Question :-- log4j:WARN Please initialize the log4j system properly.
ANSWER you should add below line in main method class its working
PropertyConfigurator.configure("src/main/java/com/nsettle/config/log4j.properties");
Maybe it looks silly to ask this but I am confused. I referred to Configuring Log4j property but it doesn't seem to help.
I have written a simple web service HelloWorld. And while running it I am getting the error something like this :
log4j:WARN No appenders could be found for logger (org.apache.axis.transport.http.AxisServlet).
log4j:WARN Please initialize the log4j system properly.
I am not sure why its happening.
I am generating the web-service using Eclipse and deployed in Tomcat 6.0. I check on Axis Developer's Guide and according to them
log4j.configuration=log4j.properties
Use this system property to specify the name of a Log4J configuration file. If not specified, the default configuration file is log4j.properties. A log4j.properties file is provided in axis.jar.
I didn't find log4j.properties in the axis.jar.
Any help on this?
Those messages are something tricky, enough so that people created this to make it clearer:
https://issues.apache.org/bugzilla/show_bug.cgi?id=25747
What's tricky about them is that the warnings are written if Log4j can't find its log4j.properties (or log4j.xml) file, but also if the file is fine and dandy but its content is not complete from a configuration point of view.
The following paragraph is taken from here:
http://svn.apache.org/repos/asf/logging/log4j/tags/v1_2_9/docs/TROUBLESHOOT.html
Logging output is written to a target by using an appender. If no appenders are attached to a category nor to any of its ancestors, you will get the following message when trying to log:
log4j: No appenders could be found for category (some.category.name).
log4j: Please initialize the log4j system properly.
Log4j does not have a default logging target. It is the user's responsibility to ensure that all categories can inherit an appender. This can be easily achieved by attaching an appender to the root category.
You can find info on how to configure the root logger (log4j.rootLogger) in the log4j documentation, basically adding something as simple as this at the beginning of the file:
log4j.rootLogger=debug, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n
This should clear those WARN messages you get on startup (make sure you don't already have an appender named stdout; also be carefull of what level you give the root logger, debug will be very verbose and every library in your app will start writing stuff to the console).
As about the log4j.properties/log4j.xml, I suggest you place this file in /WEB-INF/classes as it is important to have it exposed for different tweaks (activating/deactivating logs, changing log levels etc). You can have it inside a JAR in the classpath also (as you specified in your comment), but it will be enclosed in the archive (hopefully in the right place inside the archive) and won't be as easy to handle as if it were in /WEB-INF/classes.
You have to create your own log4j.properties in the classpath folder.
Well, if you had already created the log4j.properties you would add its path to the classpath so it would be found during execution. Yes, the thingy will search for this file in the classpath.
Since you said you looked into axis and didnt find one, I am assuming you dont have a log4j.properties, so here's a crude but complete example.
Create it somewhere and add to your classpath. Put it for example, in c:/proj/resources/log4j.properties
In your classpath you simple add .......;c:/proj/resources
# Root logger option
log4j.rootLogger=DEBUG, stdout, file
# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Redirect log messages to a log file, support file rolling.
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=c:/project/resources/t-output/log4j-application.log
log4j.appender.file.MaxFileSize=5MB
log4j.appender.file.MaxBackupIndex=10
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
If the below statment is present in your class then your log4j.properties should be in java source(src) folder , if it is jar executable it should be packed in jar not a seperate file.
static Logger log = Logger.getLogger(MyClass.class);
Thanks,
Warning No appenders could be found for logger means that you're using log4j logging system, but you haven't added any Appenders (such as FileAppender, ConsoleAppender, SocketAppender, SyslogAppender, etc.) into your configuration file or the configuration file is missing.
There are three ways to configure log4j: with a properties file (log4j.properties), with an XML file and through Java code (rootLogger.addAppender(new NullAppender());).
If you've property file present (e.g. when installing Solr), you need to place this file within your classpath directory.
classpath
Here are some command suggestions how to determine your classpath value:
$ echo $CLASSPATH
$ ps wuax | grep -i classpath
$ grep -Ri classpath /etc/tomcat? /var/lib/tomcat?/conf
or from Java: System.getProperty("java.class.path").
Tomcat
If you're using Tomcat, you may place your log4j.properties into: /usr/share/tomcat?/lib/ or /var/lib/tomcat?/webapps/*/WEB-INF/lib/ folder.
Solr
For the reference, Solr log4j.properties looks like:
# Logging level
solr.log=logs/
log4j.rootLogger=INFO, file, CONSOLE
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%-4r [%t] %-5p %c %x \u2013 %m%n
#- size rotation with log cleanup.
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.MaxFileSize=4MB
log4j.appender.file.MaxBackupIndex=9
#- File to log to and log format
log4j.appender.file.File=${solr.log}/solr.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%-5p - %d{yyyy-MM-dd HH:mm:ss.SSS}; %C; %m\n
log4j.logger.org.apache.zookeeper=WARN
log4j.logger.org.apache.hadoop=WARN
# set to INFO to enable infostream log messages
log4j.logger.org.apache.solr.update.LoggingInfoStream=OFF
If you are using Logger.getLogger(ClassName.class) then place your log4j.properties file in your class path:
yourproject/javaresoures/src/log4j.properties (Put inside src folder)
You can configure log4j.properties like above answers, or use org.apache.log4j.BasicConfigurator
public class FooImpl implements Foo {
private static final Logger LOGGER = Logger.getLogger(FooBar.class);
public Object createObject() {
BasicConfigurator.configure();
LOGGER.info("something");
return new Object();
}
}
So under the table, configure do:
configure() {
Logger root = Logger.getRootLogger();
root.addAppender(new ConsoleAppender(
new PatternLayout(PatternLayout.TTCC_CONVERSION_PATTERN)));
}