I am trying to build an project in Eclipse (actually I'm using RAD, so basically eclipse, and when I say 'Java EE Project' I mean an 'Enterprise Application Project').
My Enterprise Application Project (the 'EAR' project) has two module projects :
- service
- web
The service project has some stuff in it, all wired up using Spring.
The web project has its own stuff in it, all wired up using Spring. The UI stuff in the web project needs to use the stuff in the service project.
Both projects are included in the EAR project as modules.
The web project lists the 'service' project as a dependent project in the build path, it's checked off for export, and also has it listed as a EE Module Dependency.
I'm having a really hard time to get this working though:
The spring context in the web project is of course what gets loaded when the application is deployed, and it imports the spring config I need from the service project. This seems to be working fine.
When spring tries to instantiate a bean it throws a ClassNotFoundException. On the very first bean.
I tried simply copying the spring config from my service context and pasting it into my web context, but I got the same ClassNotFoundException.
I have tried instantiating an object of that type (the class that spring says cannot be found) in the java controller class in the web project, and it is successful, both at compile time (no compile errors) and at runtime (no exceptions).
So the classes from my service project are not available on the classpath when spring tries to use them.
Any ideas what's going on here and/or what I might be able to do about it?
There is a class loader policy that you should use ParentClass First . That will be managed either through Application.xml or through web.xml . You need to check your xml's then try.
It's a class loader issue.
Since you're using Spring, I'll assume that you don't have EJBs. If that's the case, why do you need an EAR? Deploy the whole thing as a web project, in a single WAR.
Put all your .class and Spring configuration .xml files in WEB-INF/classes. Load the configuration using org.springframework.web.context.ContextLoaderListener.
I seem to have fixed this - I'm not sure exactly what the problem was but there must have been a small typo in my spring config. I decided to just start fresh with a new spring config and when I started building the new one back up things were working fine. There must have been a problem with the old one.
Thanks for the suggestions though.
Unfortunately we're not always able to change project structure. We're working on structures other people have put in place.
I looked into the ParentClassFirst vs ParentClassLast setting - it seems on websphere the ParentClassFirst setting is the default if you don't specify anything, so I'm leaving it without specification to get that functionality.
http://publib.boulder.ibm.com/infocenter/wasinfo/v6r0/index.jsp?topic=/com.ibm.websphere.express.doc/info/exp/ae/crun_classload.html
Related
I'm trying to set a custom log Handler in my Spring Boot (version 2.6.3) application. The result is a ClassNotFound as described in this other question
Can't override java.util.logging.LogManager in a Spring Boot web application: Getting java.lang.ClassNotFoundException on already loaded class
Based on the answer to that question, it seems I need my Handler and all its dependencies to be placed into the root of the executable jar.
Is there a direct way to accomplish this during the Maven build, i.e. not by extracting and repackaging the jar myself post-build?
This issue is a result of BOOT-INF fat jar structure introduced by Spring Boot 1.4.
There is currently no straightforward solution, and it appears some of the Spring Boot maintainers do not agree there is a problem, so it could be a long time before the situation changes:
Issue #6626: Make it easier to package certain content in the root of a fat jar
Issue #12659: Starting executable war with -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager produces a ClassNotFoundException
WORKAROUND #1
I had to do two things to get my application working again with a custom log handler. 1) use Maven Shade to package up the log handler with all its dependencies, and 2) launch the app with using the PropertiesLauncher class in the command line instead of using java -jar:
java -cp executable.jar:logger-shaded.jar -Dloader.main=mypackage.myapp org.springframework.boot.loader.PropertiesLauncher
The executable.jar, logger-shaded.jar, and mypackage.myapp are placeholders specific to my project, so adjust accordingly.
WORKAROUND #2
If the handler is loaded from code in a config class or from main() instead of being specified in the file loaded via java.util.logging.config.file, as discussed in the comments to the answer in this other question, then everything works as expected. I actually prefer this over Workaround #1 as it results in a smaller deployment, but it does require writing a few more lines of code.
I am creating a library using spring-boot (v2.1.6.RELEASE) as a starter project that will facilitate as base extension jar responsible for configuring and starting up some of the components based on client project properties file.
The issue I am facing is that if the client project's SpringBoot Application class contains the same package path as library everything works like charm! but when client project contains different package path and includes ComponentScan, it is not able to load or start components from the library.
Did anyone encounter this issue? how to make client application to auto-configure some of the components from library jar?
Note: I am following the library creation example from here: https://www.baeldung.com/spring-boot-custom-starter
There are many things that can go wrong here, without seeing relevant parts of actual code its hard to tell something concrete. Out of my head, here are a couple of points for consideration that can hopefully lead to the solution:
Since we use starters in our applications (and sometimes people use explicit component scanning in there spring applications) and this obviously works, probably the issue is with the starter module itself. Don't think that the fact that the component scan is used alone prevents the starter from being loaded ;)
Make sure the starter is a: regular library and not packaged as a spring boot application (read you don't use spring boot plugin) and have <packaging>jar</packaging> in your pom.xml or whatever you use to build.
Make sure you have: src/main/resources/META-INF/spring.factories file
(case sensitive and everything)
Make sure that this spring.factories file indeed contains a valid reference on your configuration (java class annotated with #Configuration). If you use component scanning in the same package, it will find and load this configuration even without spring factories, in this case, its just kind of another portion of your code just packaged as a separate jar. So this looks especially "suspicious" to me.
Make sure that #Configuration doesn't have #Conditional-something - maybe this condition is not obeyed and the configuration doesn't start. For debugging purposes maybe you even should remove these #Conditional annotations just to ensure that the Configuration starts. You can also provide some logging inside the #Configuration class, like: "loading my cool library".
This is a strange problem. I have an existing JEE project that is and has been in production on WebSphere 7. It is a multi-module EAR file. It has 2 WARs and 1 shared Java project. Most of it is Spring 4 based, but we have some web services we host using axis2 (1.5.4). This project does not use Maven. It does use a WebSphere deployment.xml (in the EAR) with the warClassloaderPolicy="SINGLE" and the classloader mode="PARENT_LAST". This controls the classloader policies for this EAR. All the jar files that the Java project and the WARs rely on are stored at the EAR level and referenced at the module level via the manifest files. That all works fine and has for several years.
Now I was trying to convert this project to a Maven project after all these years. Initially, I left the deployment.xml file settings as they always have been. But with these settings I was getting:
java.lang.VerifyError at com.sun.xml.bind.v2.model.impl.RuntimeBuiltinLeafInfoImpl "org.springframework.oxm.jaxb.Jaxb2Marshaller".
After much googling on this site and all around and trying 50,000 things, I tried one thing, which worked for most of the app. I switched the classloader mode to "PARENT_FIRST" and all of a sudden the WAR that exclusively uses Spring 4 worked. It started up without error and I was able to run it.
But, the other WAR which hosts the axis2 web services started getting the error:
org.apache.axis2.deployment.WarBasedAxisConfigurator <init> org.apache.commons.fileupload.FileUploadException....Caused by: java.lang.NoClassDefFoundError: org.apache.commons.fileupload.FileUploadException....Caused by: java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileUploadException
This class (org.apache.commons.fileupload.FileUploadException) is in both the compile and runtime classpath. In eclipse I can see it in the "Maven Dependencies" library that the m2e eclipse plugin creates from the POM files. I can also see this jar in the WebSphere runtime module classpath inspector (it shows up in there 3 times! Once under each WAR and once just in a list from the Maven repository location.)
One thing of note is that I've configured the project with a parent POM, where most of the dependencies are declared at the parent and then are inherited for each of the modules. In the EAR project, the POM is using the maven-ear-plugin with skinnyWars=true. However, it appears the skinnyWars directive is not respected when the m2e eclipse plugin deploys the EAR into the local WebSphere server (that is evident because I see these jars showing up in the classpath 3 times). But when I create an EAR using the Maven build, the EAR comes out correctly with each jar only showing up in the EAR one time.
This is my last hope to post something here and see if someone has an idea for something to try, otherwise I can't think of anything else to try.
Thanks...
Is there a particular reason you need to run with a single class loader for all the WAR modules, other than convenience? If not, you could rework the application in order to allow you to run PARENT_FIRST in the Spring WAR and PARENT_LAST in the Axis2 WAR.
If that's not an option for some reason, the path of least resistance might be to go back to PARENT_LAST and remove some libraries from the app or module. The VerifyError generally occurs if you're running with PARENT_LAST and have a library in the app that is also present in the server - in this case, the exception looks like it's coming out of JAXB, so you might want to see if simply removing JAXB (and perhaps JAXP, if present, since it's heavily used by JAXB) from the application resolves the issue with your default setup.
You could also stick with PARENT_FIRST and move the Axis2 jars to an shared library with an isolated class loader, associated with the app. An isolated shared library would make just the stuff in the shared library PARENT_LAST, so you can avoid the VerifyError and still get PARENT_LAST for Axis2. The issue in the PARENT_FIRST case appears to be because you're picking up WebSphere's copy of Axis2 but somehow have a dependency inserted from your app's copy - the failing class load is occurring in a server-level loader, so it doesn't see the copy in your app.
I have an application which is working fine on Websphere server (as war and Eclipse Project).
Direct deploy on Liberty through WAR is also working fine.
I was trying to deploy it on WAS Liberty through Eclipse project. There are no console errors but once the application loads, none of the following files are getting loaded in the web page: js, gif, css
Because of this the page is looking distorted and most of the functionality is lost.
Surprisingly there are some JSPs in the js folder and these are getting loaded, so looks like the folders are published properly. But for all the mentioned files (js etc), I get following error in the browser console: 500 (Internal Server Error) .
There are no errors and the server log is also clean.
My setup: WAS Liberty 8.5, RHEL 6.5. Eclipse Luna, WDT 8.5.5.2. Project having Eclipse structure, not maven.
I have tried both loose config and 'from workspace' settings
Edit1: I noticed that Spring beans are not getting initialized properly. Getting null pointer on applicationContext.getBean.
OK, found the problem.
As I guessed this was related to spring initialization, though the problem was more code related.
Due to wrong implementation of REST implementation, where the base path was set as root application path (“/”), rest API classes were getting instantiated on application load and were then making calls to code which was instantiating few Spring beans.
But at this point the Spring listeners had not fired, hence the appcontext was empty. Some of the base application object were getting initialized with empty beans and hence spring security context and related classes were failing to serve the application content properly. (Problem is spring related code is created by another team and we just get the jar, hence I am not even able to debug it properly, so I don't know where it was failing exactly)
The thing that makes it Liberty specific is: The same problematic code is working fine on Websphere full profile and Weblogic and even on Liberty if we deploy as WAR. Not sure what classloading difference is causing difference in behaviour.
Thanks to all who took time and efforts for replying.
I am facing the same issue using open liberty and Eclipse Krazo when the base path is
application path (“/”)
so i have changed the path as shown below
package io.openliberty.sample;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
#ApplicationPath("")
public class ConfigApplication extends Application {
}
Now the CSS and imgs are loading with no issues.
I'm working on a project that uses two maven projects (named core and webapp); core is built with JAR packaging and used for two different purposes: as a stand-alone app (essentially an executable JAR), and also embedded into webapp.
For its purpose as a stand-alone app, core needs to have its own logback configuration (a logback.xml file) that needs to be included on the classpath. Normal Maven convention would have me put it in src/main/resources/logback.xml. That works fine, but causes a problem when the core JAR is included in webapp. webapp needs to have its own logback configuration, but the container (tc Server or Jetty) is picking up the one from core.jar first.
I realize that logback can be told about a custom config location via a system property (-D on the command line) but that's not viable in a app container like Tomcat or Jetty.
I've read some other people asking about this situation, but none of the solutions I've seen sits well with me. One solution involved setting up a context listener that runs early in the webapp initialization and explicitly configures logback based on a <context-param>. That's a bit brutish in my opinion, and probably a hard sell to my fellow dev team when log4j "just works" in this situation.
I'm far from a Maven expert, so I'm hoping there is some elegant way to get Maven to help me here. Or perhaps some logback extension or add-on that makes it more web-app friendly. Or even a clever idea that I haven't thought of.
There are a number of possible solutions, but the easiest is to put the file in its own module and mark the dependency as provided. The, conspire to have it on the classpath when running the standalone version of the app.
The solution that we ended up using was to leave only the common "non-app" pieces (code and configuration) in core and then extract the other "app" pieces into a new module (batch-app).
The logging configuration only lives in the 2 app projects (webapp and batch-app) that depend on core. core has a logback-test.xml configuration in it, but that's excluded from the JAR that maven builds (since it's in the src/test/resources folder).