We are constructing instance of CouchBase cluster in Spring singleton bean afterProperties() method by reading the configurations (like hosts, ports, connection time outs,..). This is working well.
We were using Apache hierarchical configuration for the configurations. Apache hierarchical configurations has reload strategy and does not require server restart after the configuration changed. New configurations will be reflected in 2 minutes.
Now we got requirement to update CouchBase configurations at run time. But since Spring #afterProperties is bean life cycle method and does not execute again, we could not able to achieve what we are looking for.
Right now, we need to restart the server(Tomcat) to reflect the new settings.
Is there any mechanism in Spring or any other better approach to fulfill our requirement ( singleton bean capable to handle configuration change at run time).
Thinking in better design perspective, please provide your thoughts.
Related
I have a spring boot based spring application that is deployed into an external tomcat instance.
The application creates few datasources. These datasources are added to entitymanager and transaction manager is setup accordingly.
However, recently we have integrated programmatically an ETL tool that works with JNDI datasources. The ask here is to bind the current spring datasources into the JNDI tree at startup.
I have tried to create an initial context post datasource bean creation and bind the datasources there, however, i do see a NoInitialContext exception being thrown.
How can i bind these spring datasources into the JNDI tree of the external tomcat? Appreciate the help!
Note: I cannot/am not allowed to edit the tomcat configuration as it is initialized from a PaaS template. So need to work on the approach of being able to bind to the JNDI tree from within the application.
AFAIK this is not possible. Take a look at the JEE spec:
The container must ensure that the application component instances have only read access to their naming context. The container must throw the javax.naming.OperationNotSupportedException from all the methods of the javax.naming.Context interface that modify the environment naming context and its subcontexts.
Jakarta EE Spec - Resources, Naming, and Injection
See this SO post has some interesting code examples if you want to play around.
IMHO you can achieve what you want by creating JNDI resources and passing these to the EntityManger/Spring. But that means that the configuration would exist outside of Spring completely. So this may not do what you want to do.
I have coded a Spring Boot based web application, which is expected to be run in WildFly server. The applications runs great, but the issue is with testing.
I have the database connections, caching and transaction management dealt by the server. Now, I need to be able to test them. While I was able to get through database connection problem through a mock JNDI connection and the transaction management, I'm not sure how to deal with testing of the caching.
One solution is to use Arquillian project. But, either this project is unable to recognize Spring Boot/ I'm doing something wrong, which is causing me pain to test the application.
Can someone please suggest on solving the issue? Below are my hibernate specific properties
spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.EJB3NamingStrategy
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.SQLServer2008Dialect
spring.jpa.properties.hibernate.cache.region.factory_class=org.jboss.as.jpa.hibernate4.infinispan.InfinispanRegionFactory
spring.jpa.properties.hibernate.cache.infinispan.cachemanager=java:jboss/infinispan/container/hibernate
spring.jpa.properties.hibernate.transaction.manager_lookup_class=org.hibernate.transaction.JBossTransactionManagerLookup
spring.jpa.properties.hibernate.cache.use_second_level_cache=true
spring.jpa.properties.hibernate.show_sql=false
spring.jpa.properties.hibernate.cache.use_query_cache=false
spring.jpa.properties.hibernate.hbm2ddl.auto=none
spring.jpa.properties.hibernate.generate_statistics=true
spring.jpa.properties.hibernate.cache.infinispan.statistics=true
spring.jpa.properties.hibernate.search.default.directory_provider=infinispan
spring.jpa.properties.hibernate.search.infinispan.cachemanager_jndiname=java:jboss/infinispan/container/hibernate
I would suggest creating a separate configuration for tests. This configuration would contain a definition of a TransactionManager bean - here is an example from other post. The next step is to provide your own implementation of TransactionManagerLookup and applying it to Transport configuration - as described in the manual.
I have a REST web service exposed at http://server:8080/my-production-ws by JBoss (7). My spring (3.2) configuration has a datasource which points to a my-production-db database. So far so good.
I want to test that web service from the client side, including PUT/POST operations but I obviously don't want my tests to affect the production database.
Is there an easy way to have spring auto-magically create another web service entry point at http://server:8080/my-test-ws or maybe http://server:8080/my-production-ws/test that will have the exact same semantics as the production web service but will use a my-test-db database as a data source instead of my-production-db?
If this is not possible, what is the standard approach to integration testing in that situation?
I'd rather not duplicate every single method in my controllers.
Check the spring Profiles functionality, this should solve the problem. With it its possible to create two datasources with the same bean name in different profiles and then activate only one depending on a parameter passed to the the JVM.
I am developing a java web application in which I want to cache all the data present in a table during server start up.
Also if there are any changes in DB values, I wish to refresh the cache (without restarting the server).
I am looking for some material in spring which may help me in achieving that. But I am not able to figure it out.
Please help how can I achieve the same. Also I would like to initialize some beans on server start up.
To start with read the following docs which will get you started.
Refer to Spring document http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/cache.html
Also check this simple tutorial http://viralpatel.net/blogs/cache-support-spring-3-1-m1/
Regarding your bean initialization you can use #PostConstruct annotation on a method of the bean class. Spring will call that method after the bean is constructed.
The application that your planning to build wouldnt be an easy one. In my experience, creating an application like that would require a knowledge of the following:
1. Spring
2. Ehcache
3. JMX
4. Servlet Listeners
I want to share a singleton bean across multiple war. I know sharing ApplicaitonContext using parentContextKey attribute(Example, http://blog.springsource.org/2007/06/11/using-a-shared-parent-application-context-in-a-multi-war-spring-application/)
But this way instance of bean created multiple (for 2 war, 2 instance). I want only 1 instance across 2 war.
Another way, If i set some value in any POJO, it should be accessible in another war.
Reason i need this is, there are some beans(like HibernateSessionFactory, Datasource etc which are expensive) which are created multiple times(n instance for n war). Whereas i want to utilize same instance instead of creating same in different war.
Can anyone provide me solution for this?
You could achieve this by binding the objects into the global JNDI tree. That means that both WARs would have references to an object looked up in JNDI.
Hibernate allows you to use the hibernate.session_factory_name property (this may well be a good starting point. Data sources should already be looked up from JNDI.
One thing, I would not class a session factory or a data source as expensive, so you may well be saving a miniscule amount of memory in exchange for a lot of additional complexity, so I would ask myself the question on whether this is worth the additional maintenance headaches.
Spring provide a way to expose any bean (service) and these bean can be access from any other web application or any standalone application.
please refer Remoting and Web Service using Spring to get more details.