I have been investigating using WebSphere's Liberty profile as a light weight alternative to having a fully fledged WebSphere instance deployed on my local machine (late to the party, I know).
1 thing that I can not figure out:
How do I set Parent Last class loading to be default?
I want to deploy any application and have it automatically be parent last.
I am aware that I can deploy an EAR with the deployment.xml to trigger parent last class, or run a Jython script. However, I would rather have it be the default behavior.
Any ideas anyone?
WebSphere Version: Liberty 8.5.5.8
If you're trying to set parent-last classloading in Liberty because you had to do so in WebSphere Application Server traditional to resolve library conflicts, you should first try the application on Liberty without changing it's configuration because Liberty was designed to avoid those types of conflict. If, after that, you're still inclined to change the configuration, while you can't set it as the default, you can do something like this in your server.xml:
<enterpriseApplication location="myApp.ear" name="MyApp">
<classloader delegation="parentLast"/>
</enterpriseApplication>
Related
There's a web application and a number of environments in which it works. In each environment it has different settings like DB connection and SOAP ends-points that in their turn are defined in properties-files and accessed in the following way:
config.load(AppProp.class.getClassLoader().getResourceAsStream(
PROPERTIES_FILE_PATH + PROPERTIES_FILE_NAME));
Thus the WAR-files are different for every environment.
What we need is to build a unified WAR-file that doesn't contain any configuration and works in any environment (for now, Tomcat instance) getting its configuration from outside its WAR-file.
The answer Java Web Application Configuration Patterns, to my mind, gives the full set of common approaches but with just few examples. The most attractive way is configuring JNDI lookup mechanism. As I can guess it allows to separately configure web-applications by their context paths. But couldn't find a simple (step-by-step) instructions in both the Internet and the Tomcat's docs. Unfortunately cannot spend much time on studying this complicated stuff in order to just meet so seemingly simple and natural demand :(
Would appreciate your links at the relevant descriptions or any alternative suggestion on the problem.
If its a case of simply deploying your WAR on different environment (executed by different OS user), then you can put all your config files in the user's home folder and load them as:
config.load(new FileInputStream(System.getProperty("user.home") + PROPERTIES_FILE_NAME));
This gives you the isolation and security and makes your WAR completely portable. Ideally though, you should still provide built-in default configuration if that makes sense in your case.
The approach we've taken is based on our existing deployment method, namely to put the WAR files in the filesystem next to the Tomcat, and deploy a context.xml pointing to the WAR file to Tomcat.
The context descriptor allows for providing init parameters which is easily accessible in a servlet. We've also done some work on making this work with CDI (for Glassfish and TomEE dependency injection).
If you only have a single WAR file deployed to this Tomcat instance, you can also add init parameters to the default global context XML. These will be global and you can then deploy the WAR file directly. This is very useful during development.
I've been using an embedded neo4j server in my project so far.
Now I want to try out the new bolt protocol with a standalone server, however only for my deployed application. For convenience, I still want to use an embedded database when running from IDE (permanent) or when running tests (impermanent).
In order to support this, I've migrated from the java based configuration to the use of a ogm.properties file. Depending on the environment I run in, I want to use the file which configures the respective driver/database location.
I have placed a default configuration in the root of my resources folder. However I am not able to "override" this in other environment.
In order to do that I placed a different ogm.properties in the root folder of the deployed application. This doesn't seem to work. This the mechanism that I previously already used in order to have different application.properties and logback.xml configurations.
Is this not supported by neo4j-ogm? If not, how can one achieve this? It also isn't (trivially) possible with the java based configuration.
I am a bit confused, since this doesn't sound like such an unlikely requirement...
You can use Spring Profile for this to configure different properties for different environments and you can look here.
You can use application.properties (spring.profiles.active) to load a different profile or by using a runtime argument if you are using Spring boot with CommandLineRunner.
Is there a way to find out the java classes loaded in the server stack and replace the same with the latest version of the same without restarting the web or application server?
On Tomcat, there is an attribute called reloadable which support automatic reloading of changed classes/libraries. From Tomcat site:
reloadable
"Set to true if you want Catalina to monitor classes in /WEB-INF/classes/ and /WEB-INF/lib for changes, and automatically reload the web application if a change is detected. This feature is very useful during application development, but it requires significant runtime overhead and is not recommended for use on deployed production applications. That's why the default setting for this attribute is false. You can use the Manager web application, however, to trigger reloads of deployed applications on demand."
Sample usages is (Add following line in server.xml file):
<Context path="/webdev" docBase="/webdev" reloadable="true"></Context>
for more info, please refer http://tomcat.apache.org/tomcat-6.0-doc/config/context.html
I've got a web application, hosted with tomcat, which uses hibernate to talk to a database.
I'm looking at how I can easy the pain of configuration as I migrate from dev, to test and to prod.
I've seen JNDI mentioned a lot and at first glance it seems like a good idea. You configure a jndi resource on each tomcat instance and the web context just uses it.
However after examining it further it seems that in order to have a JNDI I've got to have all my database objects + hibernate in the tomcat lib files in order for this to work. This sounds scary to me, what if I want to deploy another context that uses a different version of hibernate?
Also, am I not just swapping the pain of maintaining configuration for the pain of breakages caused by mismatches between the installed jndi resource classes and the ones in my context.
Ideally I think what I'm wanting is to just say in tomcat. There is a database called X, it is at this server and has this user/pass.
I'd appreciate your thoughts on the best way to handle the need for different config in different environments without having an extra step after each deploy to update the config files.
Cheers,
Peter
You have confused things a bit, I believe.
JNDI is just a name assigned to a datasource pool. This datasource uses a JDBC driver which in global Tomcat classpath, but that about the only shared resource in the whole setup.
Datasource has connection URL, username, password and options for connections defined, which may differ per server, but application doesn't care about it -- all it knows is the JNDI name, e.g. "jdbc/myDatasource".
All hibernate JARs, and well as any other JARs and whats not are to be packaged within the WAR. They are "visible" only within the WAR, and therefore you can have multiple applications using conflicting versions of libraries deployed to the same Tomcat.
No need to pollute lib/ directory of Tomcat. This is a bad practice, as you correctly observed.
I'm trying to use log4j to handle the logs for a web-service which is running under Glassfish 3. Most of the guides I've seen using log4j with Glassfish want me to mess around with Glassfish global settings, which I want to avoid as there will be more than one application deployed per instance of Glassfish.
Is there any way for me to have Glassfish execute a piece of code when my web service is deployed which will allow me to call DOMConfigurator and set up log4j using my XML file?
Thanks for any help!
EDIT: The answer is to place the log4j.xml file in WEB-INF/classes. In our case, it looks as if log4j remains un-configured, but logging does still actually work as expected.
Yes. All you need to do is deploy the log4j configuration with the component you're deploying; log4j will use the locally-scoped configuration as long as it's not being referenced in a parent classloader.
Glassfish' global settings won't factor in at all in that case.