I have a spring-based java application with some useful components. As a part of the system I have a groovy script, to process some reports. I would like to call a spring component from groovy script.
When I'm writing in Java, I need to use #Autowired annotation inside the #Component, i.e.
#Component
class Reporter{
#Autowired
SearchService searchService;
void report(){
searchService.search(...);
...
}
}
How can I do the same from groovy?
At first, how I can define #Component for whole script?
The following code:
#Component class Holder{
#Autowired
SearchService searchService;
def run(){
searchService.search("test");
}
}
new Holder().run()
fails with NPE on searchService.
I'm running groovyscripts with GroovyClassloader instatiaded from Java, if it matters.
Thanks a lot in advance!
If you are using #Component, you should create Spring context as:
def ctx = new GenericApplicationContext()
new ClassPathBeanDefinitionScanner(ctx).scan('') // scan root package for components
ctx.refresh()
or in the XML:
<context:component-scan base-package="org.example"/>
Your code should work if the context is created as above. Here is an example from Groovy Codehaus
import org.springframework.beans.factory.annotation.Autowired
import org.springframework.stereotype.Component
#Component class CalcImpl3 {
#Autowired private AdderImpl adder
def doAdd(x, y) { adder.add(x, y) }
}
Three possibilities:
If your Groovy code can be pre-compiled and included in the classpath then it will be created and injected as any other bean would be during <context:component-scan>. It sounds like this may not be the case since you are using GroovyClassLoader.
Use Spring Dynamic Language Support and use <lang:groovy> to create your bean instead of using GroovyClassLoader. Then use <lang:property> to inject your properties instead of using #Autowired.
If you still need to use GroovyClassLoader then you can ask the bean to be injected by using AutowiredAnnotationBeanPostProcessor.
For example, if obj is a reference to the object created by GroovyClassLoader:
AutowiredAnnotationBeanPostProcessor aabpp =
(AutowiredAnnotationBeanPostProcessor)applicationContext.
getBean(AnnotationConfigUtils.AUTOWIRED_ANNOTATION_PROCESSOR_BEAN_NAME);
aabpp.processInjection(obj);
There is a fourth possibility too, but I am not sure if it works with GroovyClassLoader, that is to use Load-time Weaving.
Related
I know that there are questions similar to this one, but none of them have helped me. I'm following along this tutorial, and the part I can't wrap my mind around is:
#SpringBootApplication
public class Application {
private static final Logger log =
LoggerFactory.getLogger(Application.class);
public static void main(String[] args) {
SpringApplication.run(Application.class);
}
#Bean
public CommandLineRunner demo(CustomerRepository repository) {
return (args) -> {
// save a couple of customers
...
// more lines, etc...
What I don't understand is where the repository passed into demo comes from. I know that the Autowired annotation can do something like that, but it isn't used at all here.
The more specific reason I ask is because I'm trying to adapt what they do here to an application I'm working on. I have a class, separate from all of the persistence/repository stuff, and I want to call repository methods like save and findAll. The issue is that the repository is an interface, so I can't instantiate an object of it to call the methods. So do I have to make a new class that implements the interface and create an object of that? Or is there an easier way using annotations?
When creating a #Bean, adding the repository in the parameters of the bean is enough to wire the repos in your bean. This works pretty much like adding #Autowired annotation inside a class that is annotated as #Component or something similar.
Spring works mostly with interface, since that is simplier to wire vs wiring concrete classes.
Can you try #Repository before the declaration of class? Worked for me in a Spring MVC structure.
#Repository
public class EntityDAOImpl implements EntityDAO{
...
}
The thing to wrap your head around is a Spring Boot application at startup time aims to resolve its dependancy tree. This means discovering and instantiating Beans that the application defines, and those are classes annotated with #Service, #Repository, etc.
This means the default constructor (or the one marked with #Autowire) of all beans is invoked, and after all beans have been constructed the application starts to run.
Where the #Bean annotation comes into play is if you have a bean which does not know the values of it's constructor parameters at compile time (e.g. if you want to wire in a "started at" timestamp): then you would define a class with an #Configuration annotation on it, and expose an #Bean method in it, which would return your bean and have parameters that are the beans dependencies. In it you would invoke the beans constructor and return the bean.
Now, if you want a certain method of some class to be invoked after the application is resolved, you can implement the CommandLineRunner interface, or you can annotate a method with #PostConstruct.
Some useful links / references:
https://docs.spring.io/spring-javaconfig/docs/1.0.0.m3/reference/html/creating-bean-definitions.html
https://www.baeldung.com/spring-inject-prototype-bean-into-singleton
Running code after Spring Boot starts
Execute method on startup in Spring
I have utility classes exposed as beans in my source folders. I want to use some of those utilities in my test classes written in junit 4. For example , I have a utility class that has methods which marshal an object into JSON string. I want to inject this utility bean in my test class. I am unable to inject these beans using Autowired annotation. Should I copy all these classes over to test folder?
Edit:
I am trying to inject jsonUtil. Below is how my code looks like.
import static org.junit.Assert.*;
import java.math.BigDecimal;
#RunWith(MockitoJUnitRunner.class)
#SpringApplicationConfiguration(classes = ProxyApplicationMock.class)
public class ProxyApplicationMock {
#Mock
public SoapClient soapClientMock;
private JsonUtil jsonUtil;
Main Class
public class ProxyApplication {
public static void main(String[] args) {
SpringApplication.run(ProxyApplication.class, args);
}
}
Your main classes can be seen by your test classes, but not the other way around. So no, you don't need to copy them.
If your utility class is declared as a Spring managed bean in your test Spring context configuration (the class -or XML file- declared in the #ContextConfiguration) which may and probably should be different from your main configuration.
Then you can inject it in any Spring managed class, which includes your test classes if it's using the SpringJUnit4ClassRunner.
EDIT:
To sum up what we discussed in the comments, the main problem is that your test runner is not a SpringRunner (alias for SpringJUnit4ClassRunner), and thus JUnit is not running your test in a Spring context. Have a look at a test example here.
The simplest test case will look like this.
#RunWith(SpringRunner.class)
#SpringBootTest
public class CityRepositoryIntegrationTests {
#Autowired
private MySpringBean springBean;
//...
}
But as often with Spring Boot, there's some magic happening behind. #SpringBootTest is a convenient annotation that will detect automatically a class annotated with #SpringBootConfiguration, meaning if you don't have a specific Spring configuration for your test, it will use your main Spring configuration, and thus include and instanciate all the beans for your main app, and that's not usually what we want in a unit test cause we want to test a class independently by mocking its dependencies.
What you can do, is provide the Spring compenent classes you want to include in your tests, as such:
#RunWith(SpringRunner.class)
#SpringBootTest(classes = MySpringBean.class)
public class CityRepositoryIntegrationTests {
#Autowired
private MySpringBean springBean;
#Mock
private MyMockedSpringBeanDependency mocked;
//...
}
This question is to Matt, since adding comment is throwing error saying only one additional use can be notified.
NOTE: Not an Answer
I have an Application class & many config classes which are imported in Application class. Earlier it was #Configuration, which I converted to #SpringBootConfiguration in Application class and the actual Config class, whos bean I am trying to mock. Ended up in
java.lang.NoSuchMethodError: org.springframework.boot.SpringApplication.<init>([Ljava/lang/Object;)V
at org.springframework.boot.test.context.SpringBootContextLoader.getSpringApplication(SpringBootContextLoader.java:121)
at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:84)
Please suggest How do I mock, I have the same setup as specified in the ticket.
#Bean
public CacheManager cacheManager()
{
EhCacheManagerFactoryBean factoryBean = new EhCacheManagerFactoryBean();
factoryBean.setConfigLocation(new ClassPathResource("ehcache.xml"));
factoryBean.setShared(true);
return new EhCacheCacheManager(factoryBean.getObject());
}
}
I noticed a strange behaviour when using #Value with CamelConfiguration
Having an example properties file:
test.list=foo,bar,baz
and having a PropertySourcesPlaceholderConfigurer, a ConversionService and when referencing the property in some regular Spring configuration:
#Configuration
#PropertySource(value = "file:example.properties")
public class RegularConfig {
#Value("${test.list}")
List<String> testList;
}
Everything works as intended (testList contains three values: foo, bar, and baz), but when the configuration class extends org.apache.camel.spring.javaconfig.CamelConfiguration:
#Configuration
#PropertySource(value = "file:example.properties")
public class RegularConfig extends CamelConfiguration {
#Value("${test.list}")
List<String> testList;
}
(see minimal running example for both cases at https://github.com/michalmela/stackoverflow-questions/tree/master/35719697)
the testList contains one, joined value: foo,bar,baz.
Is this a misconfiguration on my side? Or some kind of bug (or feature)?
(I know the obvious workaround is to split the values manually, which is what I already went with, but I'd just like to understand what is going on here)
CamelConfiguration declare a BeanPostProcessor (camelBeanPostProcessor). BeanPostProcessor-s are instantiated by spring at first (because they have to see all others beans instantiation).
When Spring instantiate this camelBeanPostProcessor, it creates an instance of your class extending CamelConfiguration, inject the properties, and invoke camelBeanPostProcessor().
So, properties injected in this instance are injected at the beginning of the Spring ApplicationContext initialization. At this time, your ConversionService is not yet registered: The default converter is used, instead of the StringToCollectionConverter.
As a workaround, you can register explicitly a ConversionService before refreshing the applicationContext :
AnnotationConfigApplicationContext ctxt = new AnnotationConfigApplicationContext();
ctxt.getBeanFactory().setConversionService(new DefaultConversionService());
ctxt.register(...);
I know it may sound stupid but are you sure the configuration worked correctly before extending CamelConfiguration class? It doesn't look to me that #Value without using SpEL will split the list. I would use this configuration
#Value(value = "#{'${test.list}'.split(',')}")
Which version of Spring are you using?. Thanks
My application context XML is simple:
<context:component-scan base-package="com.depressio.spring" />
In that package, I have my configuration:
package com.depressio.spring
#Configuration
#ComponentScan(basePackages = "com.depressio")
public class DepressioConfiguration
{
#Inject private ApplicationContext context;
}
Within com.depressio, there's a repository (DAO):
package com.depressio.dao;
#Repository
public class ParameterDAO
{
public Parameter getParameter(long ID) { ... }
}
... and a service where injection is working just fine (no NPE when parameterDAO is used):
package com.depressio.resource;
#Service
#Path("/depressio/parameters")
public class ParameterResource
{
#Inject private ParameterDAO parameterDAO;
#Path("{id}")
public Response getParameter(long parameterID)
{
return Response.ok(parameterDAO.getParameter(parameterID).legacyFormat()).build();
}
}
However, the legacyFormat() method call there constructs another object. Within that object, I have to inject a different DAO (also annotated with #Repository, though). That injection isn't working.
So, we have the original Parameter object:
package com.depressio.domain;
public class Parameter
{
...
public LegacyParameter legacyFormat()
{
return new LegacyParameter(this);
}
}
... and the LegacyParameter where the injection isn't working:
package com.depressio.domain.legacy;
public class LegacyParameter
{
#Inject private LegacyDAO legacyDAO;
....
public LegacyParameter(Parameter newParameter)
{
// NullPointerException when using the injected legacyDAO.
}
}
I've tried a few things, including:
Using an no-args constructor for LegacyParameter, then calling a populate method so I'm not using the injected DAO until after the object is constructed. This didn't work.
Injecting the LegacyDAO into the ParameterResource and passing it in. This worked, but isn't ideal since I have to pass it around a whole lot (which injection should help avoid, no?). It did prove that LegacyDAO is injectible... just not into LegacyParameter apparently.
Adding a #Service, #Component, or #Named annotation on LegacyParameter. All end up with the NullPointerException on the line I try to reference the injected legacyDAO.
What am I missing?
As Sotirios has pointed out, it can't work since you create a regular Java object and do not give Spring a chance to enhance it.
Either let Spring create objects for which you want to enjoy the Spring 'magic' (like setting #Inject dependencies etc).
Or create your own objects and set the dependencies yourself (yourObject.setDao(dao)).
That said, there are exceptional cases in which you still want to create your objects 'on the fly' by yourself but rely on Spring to inject dependencies to these objects. In this case you should call Spring explicitly:
LegacyParameter p = new LegacyParameter(...);
applicationContext.getAutowireCapableBeanFactory().autowireBean(p);
I don't think you really need it in your case.
(see this link inject bean reference into a Quartz job in Spring? for an example when this is really required).
In addition, I would advice to simplify your configuration.
Why do you use both xml-based and java-based configuration that do actually the same? In your example you could keep only one of them and have the same effect.
Let's say we have a class:
public class MyClass {
#Autowired private AnotherBean anotherBean;
}
Then we created an object of this class (or some other framework have created the instance of this class).
MyClass obj = new MyClass();
Is it possible to still inject the dependencies? Something like:
applicationContext.injectDependencies(obj);
(I think Google Guice has something like this)
You can do this using the autowireBean() method of AutowireCapableBeanFactory. You pass it an arbitrary object, and Spring will treat it like something it created itself, and will apply the various autowiring bits and pieces.
To get hold of the AutowireCapableBeanFactory, just autowire that:
private #Autowired AutowireCapableBeanFactory beanFactory;
public void doStuff() {
MyBean obj = new MyBean();
beanFactory.autowireBean(obj);
// obj will now have its dependencies autowired.
}
You can also mark your MyClass with #Configurable annotation:
#Configurable
public class MyClass {
#Autowired private AnotherClass instance
}
Then at creation time it will automatically inject its dependencies. You also should have <context:spring-configured/> in your application context xml.
Just got the same need and in my case it was already the logic inside non Spring manageable java class which had access to ApplicationContext. Inspired by scaffman.
Solved by:
AutowireCapableBeanFactory factory = applicationContext.getAutowireCapableBeanFactory();
factory.autowireBean(manuallyCreatedInstance);
I used a different approach. I had spring loaded beans that I wanted to call from my extended classes of a third-party library that created its own threads.
I used approach I found here https://confluence.jaytaala.com/display/TKB/Super+simple+approach+to+accessing+Spring+beans+from+non-Spring+managed+classes+and+POJOs
In the non-managed class:
{
[...]
SomeBean bc = (SomeBean) SpringContext.getBean(SomeBean.class);
[...]
bc.someMethod(...)
}
And then as a helper class in the main application:
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
#Component
public class SpringContext implements ApplicationContextAware
{
private static ApplicationContext context;
public static <T extends Object> T getBean(Class<T> beanClass)
{
return context.getBean(beanClass);
}
#Override
public void setApplicationContext(ApplicationContext context) throws BeansException
{
SpringContext.context = context;
}
}
I wanted to share my solution that follows the #Configurable approach as briefly mentioned in #glaz666 answer because
The answer by #skaffman is nearly 10 years old, and that does not mean not good enough or does not work
The answer by #glaz666 is brief and didn't really help me solve my problem but, did point me in the right direction
My setup
Spring Boot 2.0.3 with Spring Neo4j & Aop starts (which is irrelevant anyway)
Instantiate a bean when Spring Boot is ready using #Configurable approach (using ApplicationRunner)
Gradle & Eclipse
Steps
I needed to follow the steps below in order to get it working
The #Configurable(preConstruction = true, autowire = Autowire.BY_TYPE, dependencyCheck = false) to be placed on top of your Bean that is to be manually instantiated. In my case the Bean that is to be manually instantiated have #Autowired services hence, the props to above annotation.
Annotate the Spring Boot's main XXXApplicaiton.java (or the file that is annotated with #SpringBootApplication) with the #EnableSpringConfigured and #EnableLoadTimeWeaving(aspectjWeaving=AspectJWeaving.ENABLED)
Add the dependencies in your build file (i.e. build.gradle or pom.xml depending on which one you use) compile('org.springframework.boot:spring-boot-starter-aop') and compile('org.springframework:spring-aspects:5.0.7.RELEASE')
New+up your Bean that is annotated with #Configurable anywhere and its dependencies should be autowired.
*In regards to point #3 above, I am aware that the org.springframework.boot:spring-boot-starter-aop transitively pulls the spring-aop (as shown here mavencentral) but, in my case the Eclipse failed to resolve the #EnableSpringConfigured annotations hence, why I explicitly added the spring-aop dependency in addition to the starter. Should you face the same issue, just declare the dependency or go on adventure of figuring out
Is there a version conflict
Why the org.springframework.context.annotation.aspect.* is not available
Is your IDE setup properly
Etc etc.
This worked for me:
#Configuration
public class AppConfig {
#Bean
public TransferService transferService() {
return new TransferServiceImpl();
}
}
See more information: https://docs.spring.io/spring-javaconfig/docs/1.0.0.m3/reference/html/creating-bean-definitions.html
Found the following way useful for my use case. Sharing here for reference, credit goes to the blogger entirely. This creates a static field and populates that from Spring and then provides a public static method which returns the field populated above.
https://sultanov.dev/blog/access-spring-beans-from-unmanaged-objects/