Using simple Log4j.properties in my java code - java

I made a simple Hibernate 3.1 java code (in eclipse) which successfully creates a table in a database. I have slfj-api-1.6.0.jar and slfj-simple-1.6.0.jar in my project. But, I don't see any Log4j logging warnings or messages in the console output. How do I make log4j log things to my console ?
My tutorial says that one of the lines I should get in the console is -
log4j.logger.org.hibernate.type = debug
I saw a couple of posts online which tell me to place a Log4j.properties file in my java project, either in src folder, or make a resources folder inside src and put it there. I found one Log4j.properties in my computer and placed it in the resources folder. I am not sure if I should use the settings in that file or how to edit this file as per my requirement. How do I do this correctly ?
EDIT -
The log4j.properties file -
### 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{ABSOLUTE} %5p %c{1}:%L - %m%n
### set log levels - ###
log4j.rootLogger=warn, stdout log4j.logger.org.hibernate.info
### log JDBC bind parameters ###
log4j.logger.org.hibernate.type=debug
###log schema export/update ###
log4j.logger.org.hibernate.tool.hbm2ddl=debug
Thanks.

First of all, the file name must be in lowercase. The Log4j.properties file is wrong, it's log4j.properties. This must be put in the root folder of your project (in most cases the src folder).
Secondly, you need to download the log4j jar file if you want to use SLF4J bridge with log4j. Download the latest library that you require from Apache Logging Services. Don't forget that there are 2 versions of Apache Log4J, so I suggest you try version 1.x first.
Good luck!

One thing to note is that the file should be called log4j.properties and should be placed in the root of your src or resource folder (by default at least) ... you seem to be calling it Log4j.properties
I also think that you are missing the following dependency:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.1</version>
</dependency>

The resources folder is only an option if you identify it as a source folder on the project properties!java build path!source tab.
Slf4j does not use log4j to write to the logs unless you include the slf4j-log4j[version].jar (for example, slf4j-log4j12-1.7.7.jar) jar in your project. If you include this jar, then you must not include the slfj-simple-1.6.0.jar jar in your project.
Here is a link to the slf4j online manual

Related

Where on the client to place the log4j.properties file?

A Java application makes use of the Apache logging but am unable to turn it on.
The application is a Java Web Start application which uses a signed Jar file so I am unable to make any changes to the Jar file or the code.
A log4j.properties file with the following content was created and place in all the Java_Home/bin directories on my machine to ensure it will be picked up.
log4j.appender.rollingFile=org.apache.log4j.RollingFileAppender
log4j.appender.rollingFile.File=c:/MyLoggingDir/application6.log
log4j.appender.rollingFile.layout=org.apache.log4j.PatternLayout
log4j.appender.rollingFile.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %m%n
log4j.appender.rollingFile.MaxFileSize=10MB
log4j.appender.rollingFile.MaxBackupIndex=5
log4j.appender.rollingFile.append=true
log4j.rootCategory=ALL, rollingFile
When the application starts no output is visible in the Java Console and no files are created in the c:/MyLoggingDir directory.
Is there another requirement missing that needs to be set in order to obtain output?
From the documentation of log4j:
Log4j will inspect the "log4j.configurationFile" system property and,
if set, will attempt to load the configuration using the
ConfigurationFactory that matches the file extension.
So, for example, if you put the property file in C:\Configuration\log4j.properties, you should run your application with the flag -Dlog4j.configuration="file:C:\Configuration\log4j.properties"
See also this other answer.

Log4j doesn't write logs to file

I'm using slf4j over log4j.
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.12</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.12</version>
</dependency>
The log4j.properties is in WEB-INF folder and has the following content:
log4j.rootLogger=DEBUG, stdout, file
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
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=D:\\logs\\log4j.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
On another enviroment with same version of Tomcat the same respository works just fine, logging to the file...
You said that this same configuration file was working fine on a different environment. Can you give a little detail on the differences between the environments. e.g. are they both on Windows? The fact that is was working fine on another environment suggests that your configuration is fine, but there is some issue with your environment. Here are a few things to check:
Does the tomcat process has permissions to write to that file - i.e. are administrator rights required to write to D:\logs\log4j.log?
Make sure that there aren't any temporary files lying around tomcat's directories which may be preventing your changes from taking effect. To be sure, stop tomcat, delete the expanded war from %CATALINA_HOME%\webapps, delete the contents of %CATALINA_HOME%\temp and %CATALINA_HOME%\work
Check that you don't have any other log4j config files on your classpath, as these could be overriding your log4j file and preventing it from taking effect. To double check this, you could try temporarily removing your log4j.properties file to see if you get messages saying that the logging system is not initialised properly.
Perhaps your log4j.properties isn't being read at all. If it's not found, then log4j will use a default configuration and you might not even know about it.
Try to pass this line
-Dlog4j.configuration=file:///D:/yourPathToFile/log4j.properties
as a VM Argument in your run configuration and see if it helps.
For a Maven Based Project keep your log4j.properties in src/main/resources
I had the same problem, putting the log4j.log in source work. I thought it was getting compiled in the EAR file, but was not. Assuming it was using default.
Instead of:
log4j.appender.mainAppender.File=mainloggs.log
log4j.appender.mainAppender.Append=true
use:
log4j.appender.file.File=mainloggs.log
log4j.appender.file.Append=true
Your log4j.properties file should be in WEB-INF/classes, not WEB-INF. WEB-INF is not in the web application classpath, but WEB-INF/classes is.
Try with
log4j.appender.file=org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.Append=true
If it not working. Please put your web.xml
The issue might be coming when you won't add the log4j.properties file in your classpath. To fix the same follow the steps below:-
Create a folder resources in project and put your log4j.properties in it.
Go to project properties --> Java Build Path -->Click on Add Folder -->Check the resources folder -->Click ok and its done. It should solve your problem.
I had the same problem. It used to work a while ago but not working now.
I guess this is not a problem with log4j2 or slf4j(as was in my case) but instead with the relative path to the config file.
If you have updated java or update IDE or changed some system variable or relative path of the folders then your problem is similar to mine.
Possible fixes/workarounds -
Try including the log4j2 configuration file in the artifact while
building it.
Alternatively you can get config from propertied file and hardcode
the logging in code itself - This was what worked for me.
Try using the scheme when mentioning file paths on windows. Does not need to mention it this way on other platforms but on windows you need to. I have observed issues regarding file paths without scheme.
log4j.appender.file.File=file://d:/logs/log4j.log
So I had a similar issue with the .log file not being written to when writing a web app on tomcat. In the end I changed the file path to be relative with something like .\log.log. Then I noticed that when I ran the program using tomcat 7 I found the log file in the \bin directory instead of the \log directory inside my tomcat installation.
log4j.appender.file.File=${user.home}\\Logs\\mylogfile.log
I had the same issue. Turns out, I have another web application inside Tomcat that contain another log4j.properties file. After removing this application, things are working as expected
I had this problem when migrating log4j1 to log4j2 through the Log4j 1.x bridge (log4j-1.2-api)
My logj1 configuration was correct and the log4j2 and bridge JARs were correctly placed but I forgot this step. So adding this JVM parameter worked:
-Dlog4j1.compatibility=true

Cannot find log file in my project logs folder in spring mvc project

I use log4j in my spring mvc project and I create log file uing log4j.properties in the following.
# Root logger option
log4j.rootLogger= INFO, info, file, stdout, error
# Direct log messages to a log file [INFO]
log4j.appender.info=org.apache.log4j.DailyRollingFileAppender
log4j.appender.info.File=.logs\\mylog.log
log4j.appender.info.Threshold=INFO
log4j.appender.info.MaxFileSize=1Kb
log4j.appender.info.MaxBackupIndex=10
log4j.appender.info.DatePattern='.'yyyy-MM-dd
log4j.appender.info.layout=org.apache.log4j.PatternLayout
log4j.appender.info.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
I want it to be stored in myapp/logs folder in my web application . what part i should for the file.
here is the directory
Right now it will be saved in the current working directory of your IDE (Eclipse or STS, I guess). Its not a good idea to put the file in the project structure, because that structure wont exist, once you deployed the app anywhere.
In Spring you can define a property in youe web.xml, to make the location variable:
<context-param>
<param-name>webAppRootKey</param-name>
<param-value>mywebapp.root</param-value>
</context-param>
Then add a variable to your config:
log4j.appender.info.File=${mywebapp.root}/logs/mylog.log
If you have to store it in the application, you can also define that programmatically, by makeing use of "ServletContext.getRealPath(".") to find out where your app is deployed, and then set the path to the file.
In the normal scenario web-app checks for your log file at the root of your class path. To load a file from custom location , have a look at below posts
Change location of log4j.properties
How to use custom file instead of log4j.properties
EDIT :
From op's comment to generate your log file in the projects path , where you have placed your logs directory . you can simply specify it as ,
log4j.appender.file.File= logs/mylog.log

Seperate logs for different jars in war file

I have a war file which is deployed on jboss server. This war contains some jar files.
What i need is to create seperate logs for different jars.
I am using log4j for logging purpose and also intergrated log4j properties file in each jar.
My log4j for every jar have different paths.
Still the logs are generated in server.log of jboss.
I need help to generate seperate logs for every jar.
If you want to make different log file for different jar, you will have to configure it in your log4j.properties file related to every jar(I assume that every jar have different package naming convention).
Here is an example like if you want to log message in different file whose package name starts with org.jar1 and org.jar2.
log4j.debug=true
log4j.logger.org.jar1=DEBUG,jar1logger
log4j.logger.org.jar2=DEBUG,jar2logger
log4j.additivity.org.jar1=false
log4j.additivity.org.jar2=false
log4j.appender.jar1logger=org.apache.log4j.RollingFileAppender
log4j.appender.jar1logger.layout=org.apache.log4j.PatternLayout
log4j.appender.jar1logger.layout.ConversionPattern=%d [%t]<%-5p> %c -> %m%n
log4j.appender.jar1logger.File=/var/log/mylog/jar1.log
log4j.appender.jar1logger.Append=true
log4j.appender.jar1logger.MaxFileSize=1024KB
log4j.appender.jar1logger.MaxBackupIndex=5
log4j.appender.jar2logger=org.apache.log4j.RollingFileAppender
log4j.appender.jar2logger.layout=org.apache.log4j.PatternLayout
log4j.appender.jar2logger.layout.ConversionPattern=%d [%t]<%-5p> %c -> %m%n
log4j.appender.jar2logger.File=/var/log/mylog/jar2.log
log4j.appender.jar2logger.Append=true
log4j.appender.jar2logger.MaxFileSize=1024KB
log4j.appender.jar2logger.MaxBackupIndex=5
Based on your requirement whether you want to create log on daily basis or on size basis you have to change your configuration.
Keep in mind if any jar whose package name in any jars start with org.jar1 then all logs will be written into jar1.log file.

Why can't tomcat find my log4j.properties file?

My web app seems to be working fine. I decided to add some logging. When I deployed the war file, the application failed with an exception because tomcat didn't know about log4j.jar.
I added the jar to the WEB-INF/lib folder and redeployed. The exception went away. This lets me know that WEB-INF/lib is on the classpath.
However, now logs/catalina.out has the following typical error message:
log4j:WARN No appenders could be found for logger (com.this.that.Validate).
log4j:WARN Please initialize the log4j system properly.
So, I copied my log4j.properties file into the WEB-INF/lib folder.
The log4j warning still gets displayed, and nothing is getting logged as far as I can tell.
I'd appreciate some guidance on solving this. I'm chasing my tail.
Update
I believe my first issue is resolved - I no longer get the warning message. I think what was happening was that I had a unix shell with a pwd in the exploded file hierarchy and this prevented Tomcat from successfully removing the old project.
LOG4j
My log4j.properties file is
log4j.rootLogger=DEBUG, FILE
log4j.appender.FILE=org.apache.log4j.RollingFileAppender
log4j.appender.FILE.File=prog1.log
log4j.appender.FILE.MaxFileSize=100KB
# Keep one backup file
log4j.appender.FILE.MaxBackupIndex=1
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=%p %t %c - %m%n
Resolution
I changed the ' log4j.appender.FILE.File=prog1.log' line to instead have an explicit path to the tomcat logging folder.
Thanks all, your ideas helped me solve this and get 3.18% smarter.
Copy log4j.properties into WEB-INF/classes.

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