I am having here a ApplicationConfiguration class:
#Configuration
#PropertySource("classpath:application.properties")
public class ApplicationConfiguration implements DatabaseConfiguration {
#Value("${jdbc.driver}")
private String jdbcDriver;
// ..
#Override
public String getJdbcDriver() {
return this.jdbcDriver;
}
// ..
}
which provides certain kind of information about my application e.g. which JDBC driver I want to use. However, I don't know how I can use it as I am bootstrapping my server. How can I get hands on the initialized ApplicationConfiguration object and what is the best place to do this with Spring.
My current ansatz is using a ServletContextListener but at this point I don't know how to access the configuration object either:
public class BootstrappingServerConfig implements ServletContextListener {
#Override
public void contextInitialized(ServletContextEvent event) {
// ..
// How can I load my application configuration at this point
// or is there a better place to do that actually?
ApplicationConfiguration applicationConfiguration;
try {
SqlDatabaseBootstrapper.executeMigration(dataSource, applicationConfiguration);
} catch(Exception e) {
throw e;
}
}
// ..
}
What can I do here? Is it a good idea to use a #Configuration object like that in the ServletContextListener or would I do this kind of initialization somewhere else? If it's okay what I plan to do .. how can I get the configuration object?
Related
I try to get spring boot working with cdi events.
I have the following class which fires the event.
#Component
#UIScope
public class Login extends LoginOverlay
{
#Autowired
private UserInfo userInfo;
#Inject
private Event<UpdateCWViewEvent> cwevent;
#PostConstruct
public void init()
{
addLoginListener(new ComponentEventListener<LoginEvent>()
{
#Override
public void onComponentEvent(LoginEvent event)
{
userInfo.login(event.getUsername(), event.getPassword());
if (userInfo.isLoggedIn())
{
setButtonLabel();
close();
cwevent.fire(new UpdateCWViewEvent());
}
}
});
}
}
And in another class the following method
public void update(#Observes(notifyObserver=Reception.IF_EXISTS) UpdateCWViewEvent event)
{
//do something
}
Now I have the following problem. I need an Implementation of javax.enterprise.event.Event. I tried to take weld and use the standard Eventimpl. Now, I tried to configure a Spring Configuration class to tell my application, there is an implementation of my event.
#Configuration
public class Config
{
#Bean
public Event<UpdateCWViewEvent> cwEvent()
{
//return EventImpl.of(injectionPoint, beanManagerImpl);
}
}
I dont know what to do with the injectionPoint and beanManagerImpl. Does anybody of you had the same problem and solved it? Or does anybody have an alternative to fire easy cdi events in a spring boot application?
Thank you very much and stay healthy!
Im studying for the Spring Core cert exam, and i'm doing some testing of the framework.
I'd like to know if there is a way to know if a Bean was proxied by CGLIB or the JDK library.
I already know the basic concepts like if you declare a Bean using the interface Spring will use the JDK to proxy it (unless you tell it otherwise). And if you declare a bean directly on a class it will proxy it by inheritance using CGLIB.
What I would like to know is what should I look for while debugging to check which library was used.
Given the following code, when I debug it, I dont see any difference in the instances of the beans created. I was expecting to see something like ConcreteBean$CGLIB in the bean that has no interface...
EDIT: i now understand that proxies are only created by spring when functionality needs to be added by a PostProcessor, but still, i'd like to know what to look for in the debugger to find if CGLIB was applied or not.
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = MainConfig.class)
public class ProxiesTest {
#Autowired
RandomBean randomBean;
#Autowired
ConcreteBean concreteBean;
public void setUp() {
}
#Test
public void randomBeanTest() {
randomBean.doSomething();
}
#Test
public void concreteBeanTest() {
concreteBean.doSomething();
}
}
public class ConcreteBean {
public void doSomething() {
String concreteBean = "hello";
}
#PreDestroy
public void destroy() {
System.out.print("ConcreteBean Destroy");
}
}
public interface RandomBean {
public void doSomething();
public void destroy();
}
public class RandomBeanImpl implements RandomBean {
#Autowired
ApplicationContext context;
public void doSomething() {
context.getParentBeanFactory();
}
public void destroy() {
System.out.print("RandomBean destroyed");
}
}
#Configuration
#ComponentScan(basePackages = "com.certification.postprocessors")
public class MainConfig {
#Bean
public ConcreteBean concreteBean(){
return new ConcreteBean();
}
#Bean
public RandomBean randomBean() {
return new RandomBeanImpl();
}
}
When a bean is wrapped by a Spring CGLIB proxy it states $$EnhancerBySpringCGLIB.
A JDK proxy is shown as $Proxy
It looks like this in the debugging console
There have been several arguments around not using ApplicationContext.getBean() to get a bean reference, of which most are based on logic that it violates the principles of Inversion of control.
Is there a way to get reference to prototype scoped bean without calling context.getBean() ?
Consider to use Spring Boot!
Than you can do something like this...
Runner:
#SpringBootApplication
public class Runner{
public static void main(String[] args) {
SpringApplication.run(Runner.class, args);
}
}
Some Controller:
#Controller
public class MyController {
// Spring Boot injecting beans through #Autowired annotation
#Autowired
#Qualifier("CoolFeature") // Use Qualifier annotation to mark a class, if for example
// you have more than one concreate class with differant implementations of some interface.
private CoolFeature myFeature;
public void testFeature(){
myFeature.doStuff();
}
}
Some cool feature:
#Component("CoolFeature") // To identify with Qualifier
public class CoolFeature{
#Autowired
private SomeOtherBean utilityBean;
public void doStuff(){
// use utilityBean in some way
}
}
No XML files to handle.
We can still access context for manual configurations if needed.
Suggested reading:
Spring Boot Reference
Pro Spring Boot
This type of problem can be solved using method injection, which is described in more detail here: https://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html#beans-factory-method-injection
This is the most common approach to create prototype bean:
abstract class MyService {
void doSome() {
OtherService otherService = getOtherService();
}
abstract OtherService getOtherService();
}
#Configuration
class Config {
#Bean
public MyService myService() {
return new MyService() {
OtherService getOtherService() {
return otherService();
}
}
}
#Bean
#Scope("prototype")
public OtherService otherService() {
return new OtherService();
}
}
I'm trying to implement a custom Converter for an Entity to a Resource object with Spring Data Rest, but the Converter is never invoked.
I'm following this documentation:
If your project needs to have output in a different format, however,
it’s possible to completely replace the default outgoing JSON
representation with your own. If you register your own
ConversionService in the ApplicationContext and register your own
Converter, then you can return a Resource
implementation of your choosing.
That's what I've tried to do.
I have a #Configuration class that extends RepositoryRestMvcConfiguration, with this method:
#Configuration
#EnableWebMvc
#EnableHypermediaSupport(type = HypermediaType.HAL)
public class RepositoryBaseConfiguration extends RepositoryRestMvcConfiguration {
#Override
public DefaultFormattingConversionService defaultConversionService() {
return super.defaultConversionService();
}
}
And I have a Class that extends RepositoryRestConfigurerAdapter, with this implementation:
#Configuration
public class RepositoryBaseConfigurerAdapter extends RepositoryRestConfigurerAdapter {
#Override
public void configureConversionService(ConfigurableConversionService conversionService) {
if(!conversionService.canConvert(Entity.class, Resource.class))
conversionService.addConverter(new EntityConverter());
super.configureConversionService(conversionService);
}
}
Both methods of those two classes are correctly invoked and managed, so it's natural to think that the Converter has been registered in the Application Context...
This is my custom converter EntityConverter:
#Component
public class EntityConverter implements Converter<Entity, Resource> {
#Override
public Resource convert(Entity source) {
System.out.println("method convert of class EntityConverter");
return null;
}
}
The method "convert" is never invoked by Spring Data Rest.
What's wrong/missing ?
Thanks in advance.
How can I run some code inside a Spring Container after all beans has been loaded? I know I can use #PostConstruct for a single bean, but I would like to run that piece of code after all PostConstructs are called.
Is is possibile?
---UPDATE---
I tried to follow the ApplicationListener way, this is the implementation:
#Component
public class PostContructListener implements ApplicationListener<ContextRefreshedEvent> {
private static Logger log = LoggerFactory.getLogger(PostContructListener.class);
public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {
Collection<Initializable> inits= contextRefreshedEvent.getApplicationContext().getBeansOfType(Initializable.class).values();
for (Initializable initializable : inits) {
try{
log.debug("Initialization {} ",initializable.getClass().getSimpleName());
initializable.init();
}catch(Exception e){
log.error("Error initializing {} ",initializable.getClass().getSimpleName(),e);
}
}
}
}
Applying "Initializable" interface to all services I got what I needed, how every this way I broke all autowires, I cannot understand why but seems to be connected to the new "Initializable" interface:
java.lang.IllegalArgumentException: Can not set com.service.MyService field com.controller.RestMultiController.myService to com.sun.proxy.$Proxy41
I think you need this.
public class SpringListener implements ApplicationListener<ContextRefreshedEvent>{
public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent ) {
// do things here
}
}
http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#context-functionality-events