Develop Reference

Ignore dependency log4j.properties

I have a web application deployed on WildFly 10. After adding a new Maven dependency to my application, logging stopped working. Investigating, I've found that the new dependency includes a log4j.properties in its JAR, and I guess this is causing the logging to screw up.
I cannot delete the file from the JAR, since every time my project compiles it would come back. I need WildFly to manage the logging properties, so adding an additional log4j.properties isn't an option (it would be if it can be configured to fallback to WildFly defaults, but I don't know if this is possibile).
How can I ignore a dependency's log4j.properties or override it with WildFly's settings?

If your app does not use is own log4j properties file or xml, you are best just disabling the per-deployment logging configuration option on wildfly, then any will be ignored

You can exclude Logging module from you jar.
dependencies {
compile group : 'com.chapter1' name: 'common.all', version: '1.0.001'{
exclude( // here u can exclude that module... )
}

In WildFly 10 you can set the use-deployment-logging-config on the logging subsystem to false which will skip processing any logging configuration files. Do note this will skip processing on all deployments.

Spring boot configuration in a multi-Module maven project

I'm having a problem properly setting up spring boot for my multi-module maven project.
There is a module "api" that uses another module "core". Api has an application.properties file that contains spring.mail.host=xxx. According to the spring boot documentation this provides you with a default implementation of the JavaMailSender interface, ready to be autowired.
However the class that is responsible for sending out the e-mails resides in the "core" package. When I try to build that module the build fails because no implementation of JavaMailSender can be found.
My guess then was that the mailing config should reside in "core" in a separate application.properties. I created that and moved the spring.mail.host property from the "api" to the "core" property file.
This time the core module builds successfully, but "api" fails to build because of the same exception, so I think I just moved the problem.
I don't understand the required structure for handling this type of situations well enough so I was wondering what the correct way is for having a "core" module containing all the correct configuration for sending mails and having other modules use the mailing code and config that resides in it.

I found the answer in another stack overflow question: How to add multiple application.properties files in spring-boot?
It turns out there can only be 1 application.properties file in the final jar that spring boot creates. To have multiple files you have to rename one of the files to something custom. I named the properties of the core module "core-application.properties".
Then in the API module I added this to the spring boot application class:
#SpringBootApplication
#PropertySource(value = {"core-application.properties", "application.properties"})
Doing this I can correctly use the base properties file and overwrite them in the more specific modules. Also you can still create profile-specific properties file (core-application-production.properties) with this setup, no need to add those to the propertysource manually). Note that #PropertySource does not work for yaml configuration files at this moment.

there is one effective application.properties per project. you just keep 2 properties file for a success build.
when api module use core module, the application.properties in core module is overwrite by api.

Your API's pom.xml must has dependency of CORE module.

the solution is to define properties files as a value of #PropertiesSource in Starter class.
but it is beter to put "classpath:" behind the properties files.
for example in Intellij idea after adding the "classpatch:" word berhind the files name, values become to link. like this:
#SpringBootApplication
#PropertySource(value = {"classpath:core-application.properties", "classpath:application.properties"})
I hope to helped you.

Disabling JMX in a spring application

I'm trying to disable jmx so that i don't get:
org.springframework.beans.factory.BeanCreationException:
Error creating bean with name 'mbeanExporter'anymore.
I've found a partial answer saying that I should include this in the application.properties file:
spring.datasource.jmx-enabled=false
So I created the file with that one line. But how do I make sure that Spring acutally reads it? Do I need to edit something in spring.xml? If so, where?

You need to disable the setting in your application.properties file (it is automatically turned on if not set). Either edit or create this file:
src/main/resources/config/application.properties
That is for a maven project, so if not in maven, just put 'resources' at the same level as your java folder.
You will just need this single line in the file (it can be blank otherwise):
spring.jmx.enabled=false
If you want to add other settings, here are all the options:
http://docs.spring.io/spring-boot/docs/current/reference/html/common-application-properties.html

In my case, it was IntelliJ.
IntelliJ have a setting "Enable JMX agent" in the run configuration. This should be unchecked to disable JMX.
If checked, this will override any setting that you make in the application via properties/yml.

Are you using spring boot? If so you just need to place the file in src\main\resources\application.properties by default
You can check sample projects here https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples

You could try to disable jmx autoconfiguration:
#EnableAutoConfiguration(exclude={JmxAutoConfiguration.class})

Logging from Spring using Log4j under WebSphere

I'm using log4j in my WebSphere application. I need to debug class org.springframework.ejb.access.AbstractRemoteSlsbInvokerInterceptor, so I've created logger in my log4j.xml file:
<logger name="org.springframework">
<level value="INFO" />
</logger>
<logger name="org.springframework.ejb.access">
<level value="TRACE" />
</logger>
I've created also commons-logging.properties in src/main/resources of the web project (in maven):
org.apache.commons.logging.Log=org.apache.commons.logging.impl.Log4JLogger
However, Spring is NOT logging using log4j. I see no springframework logs in my debug file, but I can see some of them (INFO) in the console. Therefore I assume, the apache commons logging used by Spring is NOT logging using log4j.
Is it possible (and how) to redirect logging used by Spring to Log4j engine under WebSphere?
WebSphere 7.0, Spring 3.1.2, log4j 1.2.6, commons-logging 1.1 provided in shared library.

Try the following:
Consider using slf4j for your logging. Add log4j to your dependencies in maven.
Add jcl-over-slf4j to your maven dependencies. This redirectes each request from jcl to slf4j.
Search for the dependency commons-logging inside your maven dependencies. Exclude it, so it does not get to your deployment archive.
Delete the "commons-logging.properties"-file.
I hope that everythings works out fine now.

This technique to route JCL (including Spring) logging to your log4j configuration still works.
For the apps where we also have slf4j already (the Spring WebFlow ones), that can also be routed to your log4j configuration.
However, if you just want to see the Spring log information, you can increase its level of logging to WebSphere's own logs (SystemOut.log) via the console's Troubleshooting > Logs and Trace > server-name > Change log level details.
Add something like : org.springframework.ejb.access.*=fine (colon is the separator).
I don't know what the exact WAS levels correspond to, but fine, finer, and finest are listed under the "Trace" levels if you expand the Components and Groups area just to see what is available.
(I don't think it matters that your particular Spring package is not listed under there, BTW. I believe it should still successfully control your logging.)

How to exclude a specific log4j default configuration file?

I have a project which depends on hadoop-core.
hadoop-core has its own log4j configuration.
The default log4j configuration is loaded in my project.
I want my project not to be affected by it.
How do I solve this?

If you do not want the hadoop-core provided log4j configuration to be the one used by log4j you have to provide another configuration file that should be used.
You should have a look at the log4j manual. The section "Default Initialization Procedure" describes how log4j will try to find the initialization file and explains possibilities to match a special configuration (e.g. by setting the system property log4j.configuration).