I would like to know if is possible use external jars with web application that uses spring boot with embedded server.
Example:
java -cp external.api -jar app.war -spring.config.location=application.properties
When I use application I got errors like ClassNotFoundException for classes that are inside of external jar.
Related
We extensively use Java ServiceLoaders as a plugin infrastructure for our application components. We define interfaces, and then use the loader to load them at run time. Adding additional jars with extensions and service files are fine for our use cases.
However, i'm struggling to understand how we would be able to continue this approach while deploying an application within Wildfly. The intent is as stated above, the ability to add "extension" jars to the web-application class path without having to
Stop the server
Unzip the war
Add additional jar
Zip war
Start the server
In Tomcat, we could deploy web application folders instead of a war. So stopping the server, dropping in a jar, and starting the server worked fine. Within Wildfly (latest), it appears to not like the deployment of a folder vs war.
I've read about the modules approach, but have not been successful using this approach to get the deployed application to see the module from the service loader implementations.
Would like to know if there is an alternative solution or perhaps we are doing something wrong?
Thanks
WildFly supports exploded deployments with the deployment scanner or using the explode command with jboss-cli. Using the jboss-cli you can even update files remotely.
I have a spring boot application using ms-sql database, it deploys properly in external tomcat when the server is newly started, but when I redeploy the same war file I get the following error(the war file still deploys but is not functioning properly:
Native library mssql-jdbc_auth-8.4.1.x64.dll already loaded in another classloader when I redeploy the war file in external tomcat.
So I undeploy the war file, restart the tomcat server, and redeploy it, and it's deploying properly and working (functions and CRUD).
I am using tomcat 9.0.43 and there are no other applications deployed to the server instance.
EDIT: I am running tomcat on windows and also have the .dll file in the tomcat bin folder. Also I'm using maven for dependency management.
The program uses integrated security for DB auth
Your problem comes from the double usage you want to make of your WAR file:
on one side you need the JDBC driver whenever you run the WAR file using java -jar,
on the other side you don't want JDBC drivers in the web application's classloader, whenever the WAR file is deployed in a servlet container. The servlet container should provide the drivers.
Fortunately the spring-boot-maven-plugin already provides such a feature in the repackage goal: all the dependencies marked as provided (such as the Embedded Tomcat libraries) are placed in the WEB-INF/lib-provided folder and hence are not loaded by the servlet container.
Therefore you only need to mark the JDBC driver as provided and add it to Tomcat's common loader's classpath ($CATALINA_BASE/lib).
I'm struggling to learn how I go about building, packaging, and deploying a Spring REST API locally so that I can interact with it? Ideally, I'd just like to GET and POST data as practice -- specifically integrating with DynamoDB.
I've cloned this DynamoDB project and built it using mvn package so that I have a jar file. I moved the jar file to the webapp directory of Apache and started the server, but I cannot interact with the API in any way. The project is structured as follows:
Once Apache is running with the jar in the webapp directory, I've tried accessing the API at:
http://localhost:8080/
http://localhost:8080/springbootapp (from server.contextPath=/springbootapp in application.properties)
Each gives a 404 error. And yes, DynamoDB is running locally. So what do I need to do differently? How can I deploy and access this API locally?
The project you have cloned is a spring boot project, hence you can use mvn spring-boot:run to run the application locally.You can also run it by running the com.baeldung.Application class as a java application from the IDE. For more details on how to run a spring boot app you can follow this link. Spring boot parent has a dependency on the embedded tomcat, which will run the application.
Additionally if you want to deploy the application as a war the spring boot documentation shows how to do it.
I have a WAR with Java Spring application, which I can deploy to a Java application server. I need to run it on a machine with JRE, but without application server, i.e. with java -jar my_application.jar.
The guide "Convert an existing application to Spring Boot" is a close match, except that I do not need to create a deployable WAR as I already have it. The existing code does not use #SpringBootApplication, and I'd prefer not to mangle with it.
If you want a runnable 'Jar' file, then the jar file must contain the Web server, so you best option is to convert your application to spring boot. Spring boot is able to package an application as a war file, so it can be deployed on a Tomcat, or be launched with java -jar, but it has to be a spring boot app to begin with.
I have a Gradle, Spring Boot (web starter) application, that is built to be run either as a standalone application with the embedded container, or deployed to a container as a war.
So I from Eclipse I can run/debug the #SpringBootApplication class, and also deploy the war in Tomcat. All works fine.
Now, for some requirements, I need to know the running environment; standalone or container. Basically, we generate a MANIFEST file to the war, with a Gradle build, and refer to that file for some version/meta information. However, this would be generated only when built from Gradle. Is there any way in code I can differentiate this?