I have some java objects coming from external library which I need to inject in my spring project. Problem is the classes from library is not aware of any spring api's
If I inject the beans from library to Service using #Autowired I am getting org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type
Following is my service class
#Path("/test")
public class TestService {
#Autowired
SomeOtherClass service;
#GET
public Response get(){
return Response.ok(service.someMethod()).build();
}
}
and following is my class from library which is not aware of spring
public class SomeOtherClass {
public String someMethod(){
return "Data from library";
}
}
When I invoke my service I get exception as
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.example.SomeOtherClass' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true)}
Is there are way in spring to inject a plain Java Object similar to that of injection in **CDI**?
There is one option to define applicationcontext.xml and define SomeOtherClass in xml and use getBean, but I don't want to do that. Is there any other option?
Note:
Following options cannot be considered because I have100's of classes coming from library
Cannot use applicationcontext.xml
Cannot #Configuration #Bean to produce beans.
You could use the #Configuration and #Bean annotations as follows -
Create a new class:
#Configuration
public class AppConfig {
#Bean
SomeOtherClass someOtherClassBean(){ return new SomeOtherClass();}
}
Now the auto wiring shall work.
What it does, is actually creating a bean and letting Spring know about it.
Maybe try adding the beans programatically to the IoC container:
Add Bean Programmatically to Spring Web App Context
You need to find all the classes you want to instantiate and use one of the methods in the linked question.
You can use reflection to add Bean definitions programatically.
#Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
Reflections ref = new Reflections(new ConfigurationBuilder()
.setScanners(new SubTypesScanner(false /* don't exclude Object.class */), new ResourcesScanner())
.setUrls(ClasspathHelper.forPackage(PACKAGE_NAME))
.filterInputsBy(new FilterBuilder().include(FilterBuilder.prefix(PACKAGE_NAME))));
ref.getSubTypesOf(Object.class).stream()
.forEach(clazz -> {
logger.info("Defining pojo bean: {} -> {}", Introspector.decapitalize(clazz.getSimpleName()), clazz.getCanonicalName());
registry.registerBeanDefinition(Introspector.decapitalize(clazz.getSimpleName()),
BeanDefinitionBuilder.genericBeanDefinition(clazz).getBeanDefinition());
});
}
Subsequently, these beans can be #Autowired elsewhere. See Gist: https://gist.github.com/ftahmed/a7dcdbadb8bb7dba31ade463746afd04
Related
Here's my issue--I have a service that relies on an external library. I was trying to autowire the service so I can use it but was not able to
import org.keycloak.admin.client.token.TokenService;
public class SimpleService {
#Autowired
private TokenService keycloakTokenSvc; // Could not autowire, no beans of type 'TokenService' found
public void execute() {
keyCloakTokenSvc.doSomething();
}
}
I then added this to my SpringBootApplication and got it working:
#SpringBootApplication
#ComponentScan({"org.keycloak.admin.client.token"})
public MyApp {}
Sweet -- all good now, right? Nope. It seems like this overrides some of my auto configuraitons like my security config, so I was no longer to make RESTful requests to my application while it was running. I then did this next:
#SpringBootApplication
#ComponentScan({"org.keycloak.admin.client.token", "com.project.pkg"})
public MyApp {}
Still nothing. I get the same error as before:
Field keycloakTokenSvc in com.mark43.jms.services.TokenRefreshService required a bean of type 'org.keycloak.admin.client.token.TokenService' that could not be found.
The injection point has the following annotations:
- #org.springframework.beans.factory.annotation.Autowired(required=true)
Action:
Consider defining a bean of type 'org.keycloak.admin.client.token.TokenService' in your configuration.
I'm new to Spring Boot so not sure what to do here. Is there a way to use the TokenService without Autowiring? Is there a way to scan both packages?
It seems to me that you need to create a TokenService bean as follows:
#Configuration
public class TokenConfig {
#Bean
public TokenService tokenService() {
return new TokenService(); // Or whatever you need to instantiate it
}
}
This will register a TokenService object as a Spring-managed bean so that it can be autowired into SimpleService.
I've switched a portion of a Spring app to use functional bean registrations. The motivation for the switch is due to requiring multiple instances of some beans under certain conditions. It also turns out to be much more concise (which won't be at all apparent with the simplistic examples below).
The code used to look like this (simple example):
#Configuration
public class ConfigA {
#Bean
public BeanA beanA() {
return new BeanA();
}
}
#Service
public class Service1 {
#Autowired BeanA beanA;
...
}
#Service
public class Service2 {
#Autowired BeanA beanA;
...
}
I've switched the configuration class to look like this:
#Configuration
public class ConfigA implements ApplicationContextInitializer<GenericApplicationContext> {
#Override
public void initialize(GenericApplicationContext context) {
context.registerBean("beanA", BeanA.class, () -> new BeanA());
}
}
The issue I'm now encountering is that Spring is complaining about autowired beans not being found. With the original code, Spring could determine that a BeanA bean was declared via ConfigA and would create that bean before initializing the services.
With the new code, I guess there is no way for Spring to determine where the BeanA bean(s) are being declared, and so it tries to init the services before the BeanA is initialized (which causes the app to not start).
I was hoping that Spring would prioritize #Configuration classes over #Service or #Controller classes, but that doesn't seem to be the case.
I could annotate all the services with #DependsOn("configA"), but there are many services that autowire BeanA (some in other code bases), so the #DependsOn option isn't really realistic.
Question: When using functional bean registration, is there a way to inform Spring that ConfigA is responsible for creating an instance of BeanA?
In order to use the functional style of bean registration and enable autowiring mechanism in other beans you can do the following:
Remove #Configuration annotation from your ConfigA class;
Create directory named META-INF under main/java/resources and create a file named spring.factories under the newly created directory;
Fill the newly created file with the line org.springframework.context.ApplicationContextInitializer=(package-name-to-configA-class).ConfigA
Now Spring should be able to successfully autowire bean named BeanA where requested.
I have the following code:
This is my first class that will to call the
#Component
class DefaultBridge #Autowired constructor(
private val clientConfig: Config,
private val client: world.example.Client
) : Bridge {
override fun doEpicStuff(): String {
val request = createRequest(...)
val response = client.makeCall(request)
return response.responseBody
}
}
The Client being used (world.example.Client) then has the following piece of code:
public class Client {
#Autowired
private RestTemplate restTemplate;
public Response makeCall(Request request) {
restTemplate.exchange(....)
}
}
When running the code. I get the following Error:
NoSuchBeanDefinitionException: No qualifying bean of type
'org.springframework.web.client.RestTemplate' available: expected at
least 1 bean which qualifies as autowire candidate. Dependency
annotations:
{#org.springframework.beans.factory.annotation.Autowired(required=true)}
Where should I declare the bean when the constructor is autowired?
why won't spring automatically create the bean?
I need help understanding the problem so please don't just post the solution.
With Spring dependency injection you can inject a instance of a bean.
In Spring it's called Inversion of Control (IoC) principle. IoC is also known as dependency injection (DI).
You can define depencenies for your bean with member variable or constuctor variables. There are differnt possibilities, for example #Autowire as annotation for member variables like your usage.
The container then injects those dependencies when it creates your bean.
Attention, however, it is necessary that the spring container knows how the dependency to be injected. There are many ways to teach the container this. The simplest variant is to provide a #Bean producer method in a #Configuration class. Spring container "scans" all #Configurations at the start of the container and "registers" the #Bean producer.
Nobody has done a producer for RestTemplate. Not Spring self and also no other lib. With many other beans you use, this has already been done, not with RestTemplate. You have to provide a #Bean producer for RestTemplate.
Do this in a new #Configuration or in one of your existing #Configuration.
A #Configuration indicates that a class declares one or more #Bean methods and may be processed by the Spring container to generate bean definitions and service requests for those beans at runtime, for example:
#Configuration
public class RestTemplateConfig {
#Bean
public RestTemplate restTemplate() {
// New instance or more complex config
return new RestTemplate();
}
}
Define RestTemplate as a bean in your configuration class.
Is it possible to have a Spring Bean implement 2 interfaces and be able to autowire that bean using either interface?
I have the following two interfaces:
public interface ServiceA {}
public interface ServiceB {}
Two controllers which use constructor auto-wiring to inject a different service:
#RestController
public class ControllerA {
public ControllerA(ServiceA service) {}
}
#RestController
public class ControllerB {
public ControllerB(ServiceB service) {}
}
One class that implements both the services
#Service
public class ServiceImpl implements ServiceA, ServiceB { }
I am getting a NoSuchBeanDefinitionException:
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [ServiceB] found for dependency [ServiceB]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}
I'm using Spring Boot version 1.4.0
Yes it is possible, but
it is important, to create the service bean of type ServiceImpl and not as one of the service interfaces :
#Bean
ServiceImpl service() {
return new Serviceimpl();
}
Spring uses reflection on the declared bean type to find out which interfaces it implements and not on bean.getClass().
Even if this answer was voted dowen, you can be asured : it works . If it does not work for you #scarba05, your problem must be somewhere else...
You could use the #Qualifier annotation. It can be applied alongside #Autowired or #Inject at the point of injection to specify which bean you want to be injected:
#Autowired
#Qualifier("iceCream")
public void setDessert(Dessert dessert) {
this.dessert = dessert;
}
Source: Spring in Action 4th edition.
Let me answer your questions one by one:
Yes you can implement more than one interface in any spring bean.
Yes you can autowire with interface too as you did by constructor.
Your shared code working fine just check your SpringBootConfiguration class I think you are not scanning you service package or your service class is not in child package of SpringBootConfiguration class.
That's why you are facing:
NoSuchBeanDefinitionException
I can't find out why the following simple scenario is failing: I have a Spring application with a filter that loads a Spring bean from the application context:
public class MyFilter implements Filter{
private IPermissionService permissionService;
public void init(FilterConfig filterConfig) throws ServletException {
WebApplicationContext ac = null;
try{
ac = WebApplicationContextUtils.getRequiredWebApplicationContext(filterConfig.getServletContext());
permissionService = ac.getBean(PermissionServiceImpl.class);
PermissionServiceImpl has an #Autowired attribute dataSource so in my TestNG test, I mock it in the Spring applicationContext:
#Configuration
public class MyFilterSpringTestConfig{
#Bean
public IPermissionService permissionService(){
return Mockito.mock(PermissionServiceImpl.class);
}
MyTest:
#Test
#WebAppConfiguration
#ContextConfiguration(classes=MyFilterSpringTestConfig.class)
public class MyFilterSpringTest extends BaseSpringFilterTest{
...
The problem is that on Spring initialization I get an exception complaining that PermissionServiceImpl's dataSource dependency is not satisfied. Since I wrapped it with a mock, why is it still failing? How could I fix it?
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.sql.DataSource] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true), #org.springframework.beans.factory.annotation.Qualifier(value=myDataSource)}
When mocking a class using Mockito (or any other mocking framework) that class is still an instance of the original class. With that comes that it also contains all the annotations and class information with it.
So when you create a mock of the class it still detects all annotations on it and tries to full fill that. I.e. #Autowire other instances.
Either don't use auto wiring or don't mock the class but the interface (which doesn't contain that information).