Load external properties files into EJB 3 app running on WebLogic 11

[James Dekker]

Am researching the best way to load external properties files from and EJB 3 app whose EAR file is deployed to WebLogic.

Was thinking about using an init servlet but I read somewhere that it would be too slow (e.g. my message handler might receive a message from my JMS queue before the init servlet runs).

Suppose I have multiple property files or one file here:

~/opt/conf/

So far, I feel that the best possible solution is by using a Web Logic application lifecycle event where the code to read the properties files during pre-start:

import weblogic.application.ApplicationLifecycleListener;
import weblogic.application.ApplicationLifecycleEvent;

public class MyListener extends ApplicationLifecycleListener {
  public void preStart(ApplicationLifecycleEvent evt) {
    // Load properties files
   } 
}

Found this here

What would happen if the server is already running, would post start be a viable solution?

Can anyone think of any alternative ways that are better?

[Matt Cartwright]

the ApplicationLifeCycleListener, as the name indicates, goes with the application, not to be confused with a StartUpClass.

So even if the server is running and your application is deployed but has not been started yet (state: new) the pre-start method will be called once you start your application (i.e. from the Admin Console).

It really depends on when your application expects the properties to be available. If that is on application initialization, the pre-start would be a match. Using post start will execute the method after your application has fully initialized (state: active).

Hope that helps.
Matt

[James Dekker]

Thanks for responding, Matt!

Actually, it does load on server start up...

Using Oracle Enterprise Pack for Eclipse, I created an Enterprise Project and named it:

PropertiesDemoEAR

I also created a PropertiesDemoEARWeb module in which I put this code

(inside PropertiesDemoEARWeb / Java Resources / src / com.project.util):

package com.project.util;

public class PropertiesFileHandler extends ApplicationLifecycleListener {
 
	private static final String FILE = "C:/etc/error.properties";
 
	public void preStart(ApplicationLifecycleEvent evt) {
		System.out.println("\n\n\t\tInside preStart() method\n\n");
		InputStream is = evt.getApplicationContext().getAppClassLoader().getResourceAsStream(FILE);
		try {
			Properties convertedProps = convertStreamToProperties(is);
			String userMissingError = convertedProps.getProperty("USER_MISSING_ERROR");
			System.out.println("\n\n\t\tuserMissingError = " + userMissingError + "\n\n");
		} catch (Throwable e) {
			e.printStackTrace();
		}
		
	}
	
	public Properties convertStreamToProperties(InputStream is) throws IOException {
		System.out.println("\n\n\t\tInside convertStreamToProperties() method\n\n");
		Properties props = new Properties();
		if (is == null) {
			throw new FileNotFoundException("property file '" + FILE + "' not found");
		}
		else {
			props.load(is);
			return props;
		}
	}
}

Inside PropertiesDemoEAR/EarContent/META-INF/weblogic-application.xml

Added the following listener declaratively:

<?xml version="1.0" encoding="UTF-8"?>
<wls:weblogic-application xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-application">
    <!--weblogic-version:10.3.5-->
    <wls:application-param>
        <wls:param-name>webapp.encoding.default</wls:param-name>
        <wls:param-value>UTF-8</wls:param-value>
    </wls:application-param>
    
    <wls:listener>				
    	<wls:listener-class>com.project.util.PropertiesFileHandler</wls:listener-class>
    </wls:listener>
</wls:weblogic-application>

Right clicked on the PropertiesDemoEAR / Export / EAR file / Destination:

C:\Oracle\Middleware\user_projects\domains\MyDomain\autodeploy

When I run WebLogic 11g through Eclipse, I get this error message in the console:

[ERROR] AdapterManager - ServletContainerAdapter manager not initialized correctly.
<oracle.tip.adapter.apps.AppsConnectionFactory> ConnectionManager cm: weblogic.connector.outbound.ConnectionManagerImpl@12433e7-eis/Apps/Apps ManagedConnectionFactory mcf: oracle.tip.adapter.apps.AppsManagedConnectionFactory@4303022b
<Jun 30, 2011 5:50:24 PM PDT> <Error> <Deployer> <BEA-149265> <Failure occurred in the execution of deployment request with ID '1309481424487' for task '0'. Error is: 'weblogic.management.DeploymentException: '
weblogic.management.DeploymentException: 
	at weblogic.application.internal.flow.BaseLifecycleFlow$CreateListenerAction.run(BaseLifecycleFlow.java:176)
	at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
	at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
	at weblogic.application.internal.flow.BaseLifecycleFlow$BaseAction.invoke(BaseLifecycleFlow.java:104)
	at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:117)
	Truncated. see log file for complete stacktrace
Caused By: java.lang.ClassNotFoundException: com.project.util.PropertiesFileHandler
	at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:297)
	at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:270)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:305)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:246)
	at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:179)
	Truncated. see log file for complete stacktrace
> 
<Jun 30, 2011 5:50:25 PM PDT> <Warning> <Deployer> <BEA-149004> <Failures were detected while initiating deploy task for application '_appsdir_PropertiesDemoEAR_ear'.> 
<Jun 30, 2011 5:50:25 PM PDT> <Warning> <Deployer> <BEA-149078> <Stack trace for message 149004
weblogic.management.DeploymentException: 
	at weblogic.application.internal.flow.BaseLifecycleFlow$CreateListenerAction.run(BaseLifecycleFlow.java:176)
	at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
	at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
	at weblogic.application.internal.flow.BaseLifecycleFlow$BaseAction.invoke(BaseLifecycleFlow.java:104)
	at weblogic.application.internal.flow.HeadLifecycleFlow.createListener(HeadLifecycleFlow.java:117)
	Truncated. see log file for complete stacktrace
Caused By: java.lang.ClassNotFoundException: [b]com.project.util.PropertiesFileHandler[/b]
	at weblogic.utils.classloaders.GenericClassLoader.findLocalClass(GenericClassLoader.java:297)
	at weblogic.utils.classloaders.GenericClassLoader.findClass(GenericClassLoader.java:270)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:305)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:246)
	at weblogic.utils.classloaders.GenericClassLoader.loadClass(GenericClassLoader.java:179)
	Truncated. see log file for complete stacktrace>

Question(s):

(1) What am I possibly doing wrong? Why can't it find my PropertiesFileHandler class?

(2) Is the location (c:/etc/error.properties) of my properties file suitable or should it be inside MyDomain directory?

(3) Is there a default directory or just simple configuration area that WebLogic loads properties files which are accessible to any application that runs in WebLogic?

[Matt Cartwright]

1 - your class needs to reside in the APP-INF/classes directory structure inside your EAR file
e.g. APP-INF/classes/com/project/util/PropertiesFileHandler

2 - should work with Properties.load(), not sure though if you can use getResourceAsStream()
with an absolute path as it searches the CLASSPATH

3 - if -Dweblogic.ext.dirs is not set, it defaults to $DOMAIN/lib;$WL_HOME/common/lib/ext;$WL_HOME/server/lib/ext
so if you store error.properties in $DOMAIN/lib it will be on the CLASSPATH and you should be able to load it using
getResourceAsStream("error.properties")

Hope that helps
Matt

[James Dekker]

Thanks Mark,

Got it working... The issue was that I had it set up as web project rather than a Java EE Utility project in Oracle Enterprise Edition for Eclipse.

As a web project, it was putting the .class file inside WEB-INF/classes instead of APP-INF.

Also, needed to put error.properties inside my actual domain.

C:\Oracle\Middleware\user_projects\domains\MyDomain

Will look into -Dweblogic.ext.dirs flag...

Kindest regards.