Can I intercept Spring #Autowired process to do validation checks? - java

Sometimes we make mistakes in our code and #Autowired a prototype-scoped bean into a singleton-scoped bean. This is of course wrong because then the singleton is probably going to use that dependency as if it was also a singleton.
Is there any way of intercepting the autowiring/DI process to detect this and raise an error ? This would be for detection at development time.

The best way to achieve this is through your unit tests. For example:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = MyAppConfig.class, loader = AnnotationConfigContextLoader.class)
public class MyServiceTest {
#Autowired(required = true)
MyService myService;
#Test
public void shouldAutowire() {}
}
The #ContextConfiguration can be used with Java config as above, or it can refer to XML config files. By doing this, Spring will be used to inject all of your dependencies whenever you run your tests. By including "required = true" on your #Autowired beans, you are ensuring that Spring will throw an exception during that phase, and your test will fail. The example above may not look fancy, but it will ensure that any configuration errors are caught. Of course, you can go further and have your tests make use of the injected beans. I find that rather handy for database access integration tests.
This is not intercepting the autowiring process itself, but you can of course test that your beans are behaving correctly.
You will need to import the spring-test dependency. i.e. For Maven:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
<scope>test</scope>
</dependency>

Related

Spring Boot MVC Test - MockMvc is always null

I'm trying to write my first Spring MVC test but I just cannot get Spring Boot to inject the MockMvc dependency into my test class. Here is my class:
#WebMvcTest
public class WhyWontThisWorkTest {
private static final String myUri = "uri";
private static final String jsonFileName = "myRequestBody.json";
#Autowired
private MockMvc mockMvc;
#Test
public void iMustBeMissingSomething() throws Exception {
byte[] jsonFile = Files.readAllBytes(Paths.get("src/test/resources/" + jsonFileName));
mockMvc.perform(
MockMvcRequestBuilders.post(myUri)
.content(jsonFile)
.contentType(MediaType.APPLICATION_JSON))
.andExpect(MockMvcResultMatchers.status().is2xxSuccessful());
}
}
I've checked with IntelliJ's debugger and can confirm that mockMvc itself is null. Thus, all the Exception message tells me is "java.lang.NullPointerException".
I've already tried adding more general Spring Boot annotations for test classes like "#SpringBootTest" or "#RunWith(SpringRunner.class)" in case it has something to do with initializing Spring but no luck.
Strange, provided that you have also tried with #RunWith(SpringRunner.class) and #SpringBootTest. Have you also tried with the #AutoConfigureMockMvc annotation? The sample below is working fine.
#RunWith(SpringRunner.class)
#SpringBootTest
#AutoConfigureMockMvc
public class HelloControllerTest {
#Autowired
private MockMvc mockMvc;
#Test
public void getHello() throws Exception {
mockMvc.perform(MockMvcRequestBuilders.get("/").accept(MediaType.APPLICATION_JSON))
.andExpect(status().isOk())
.andExpect(content().string(equalTo("Hello World of Spring Boot")));
}
}
complete sample here
It may also be worthwhile to consider the following comments regarding the usage of the #WebMvcTest and #AutoConfigureMockMvc annotations as detailed in Spring's documentation
By default, tests annotated with #WebMvcTest will also auto-configure Spring Security and MockMvc (include support for HtmlUnit WebClient and Selenium WebDriver). For more fine-grained control of MockMVC the #AutoConfigureMockMvc annotation can be used.
Typically #WebMvcTest is used in combination with #MockBean or #Import to create any collaborators required by your #Controller beans.
If you are looking to load your full application configuration and use MockMVC, you should consider #SpringBootTest combined with #AutoConfigureMockMvc rather than this annotation.
When using JUnit 4, this annotation should be used in combination with #RunWith(SpringRunner.class).
I faced the same issue. It turned out that MockMvc was not injected due to incompatible #Test annotation. The import was org.junit.Test, but changing it to org.junit.jupiter.api.Test solved the issue.
Accepted answer works, however I solved the issue also without importing #RunWith(SpringRunner.class).
In my case I had imported org.junit.Test instead of the newer org.junit.jupiter.api.Test.
If you are using Maven you can avoid to make this mistake excluding junit-vintage-engine from spring-boot-starter-test dependency:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
check if you have the latest or at least updated maven-surefire-plugin.
It helped me to solve the issue

Correct way to Integrate JAX-RS with CDI?

I used to integrate Service and DAO beans in Jersey REST resources by annotating them with #Path following Java EE tutorial
In general, for JAX-RS to work with enterprise beans, you need to annotate the class of a bean with #Path to convert it to a root resource class. You can use the #Path annotation with stateless session beans and singleton POJO beans.
So my code used to be something like this:
#Path("/")
public class ServiceResource {
#Inject
private AccountService accountService;
#GET
#Path("/account/get")
public Account getAccount(#QueryParam("id") String id) {
return accountService.get(id);
}
}
#javax.inject.Singleton
#Path("")
public class AccountService {
public Account get(String id){...}
}
Now, I started integrating a Quartz Job into my application, and I wanted to find a way to inject my AccountService inside a job like this
public class AccountJob implements Job {
#Inject
private AccountService accountService;
#Override
public void execute(JobExecutionContext jec) throws JobExecutionException {
accountService.updateAllAccounts();
}
}
I found this answer that tells to use DeltaSpike to do the Job, so I added the following dependencies to my pom.xml, and without adding any more lines of code to any class the inejection of accountService to my Job works fine
<dependency>
<groupId>org.apache.deltaspike.modules</groupId>
<artifactId>deltaspike-scheduler-module-api</artifactId>
<version>1.7.2</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.apache.deltaspike.modules</groupId>
<artifactId>deltaspike-scheduler-module-impl</artifactId>
<version>1.7.2</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.apache.deltaspike.cdictrl</groupId>
<artifactId>deltaspike-cdictrl-api</artifactId>
<version>1.7.2</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.apache.deltaspike.cdictrl</groupId>
<artifactId>deltaspike-cdictrl-weld</artifactId>
<version>1.7.2</version>
<scope>runtime</scope>
</dependency>
However, I realized that when I remove the #Path("") from AccountService, its instance is still injected fine inside ServiceResource, so my questions are the following:
Why adding DeltaSpike dependencies made it possible to inject my beans without using #Path on them?
By searching more, I understood that DeltaSpike internally uses Weld to do the injection, and since I am already using GlassFish 4.0, I know that Weld is already there, so why the injection is not working by default in my Job class and in ServiceResource class without adding #Path on my beans? Actually why adding #Path is even suggested in the Java tutorial?
Is there any bad side effects that I don't see in my code, because I think that I am mixing multiple DI methods here without really understanding how do they work?
Update: After more search, I realize that Jersey doesn't use Weld for dependency injection, instead it uses HK2, a different framework that also happens to be a part of GlassFish, when I try to inject AccountService without using #Path it shows the following exception
org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object available for injection at SystemInjecteeImpl(requiredType=AccountService,parent=ServiceResource,qualifiers={}...
So this updates the questions to the following:
How to make HK2 injections works? // Without using #Path as mentioned in the Java EE Tutorial
If I managed to to do DI with HK2, will it be safe to use DeltaSpike to do DI for the Quartz Job? Is it okay to mix two CDI framewroks together to scan the classes and do the injection?
I put my my source code on pastebin; pom.xml is here and the Java is here
You do not need to set the Path annotation on your AccountService CDI bean. If CDI is enabled on your application (either with empty beans.xml in CDI 1.0 or discovery-mode=all in CDI > 1.0), you can #Inject any CDI bean in your JAX-RS resource.
So you just have to write the following class:
#Path("/")
public class ServiceResource {
#Inject
private AccountService accountService;
#GET
#Path("/account/get")
public Account getAccount(#QueryParam("id") String id) {
return accountService.get(id);
}
}
#javax.inject.Singleton
public class AccountService {
public void Account get(String id){...}
}
The article you linked in your post deals with mixing EJB and CDI annotations. For example you can mix #Stateless and #Path annotations. It's interesting for example because you can :
Benefit of EJB transaction in your Rest resource (even if now you can use #Transactional interceptor binding)
Set a pool of resources
etc.
Note that all of this works without the help of deltaspike dependency.
For your second question, as Quartz manages its own threads, classes are not handled by CDI so you can not inject beans in Quartz classes. The aim of the deltaspike module is to allow injecting CDI beans in Quartz Jobs. Internally, deltaspike controls CDI Contexts.
EDIT
For your last questions:
Your HK2 problem comes pretty sure from a missing dependency (in your application or server). As said in a previous comment, I managed to deploy your App on Glassfish 4 (build 89) with the source files you provided.
Regarding the integration of CDI with Quartz, I think the best is to implement your own JobFactory and instanciate your jobs using BeanManager. Take a look at this link : https://devsoap.com/injecting-cdi-managed-beans-into-quarz-jobs/
First of all injected resources(beans) and Jersey Endpoint class(point of injection) must be CDI-Aware. It must be detecteable by CDI. We can use bean-discovery-mode="all" - then CDI scan ALL classes or
bean-discovery-mode="annotated" and MARK our class with PROPER annotation: from here : Bean defining annotations. I prefer#Dependent or #RequestScoped
Then we must use Jersey Extension
<dependency>
<groupId>org.glassfish.jersey.ext.cdi</groupId>
<artifactId>jersey-cdi1x-servlet</artifactId>
<version>{version}</version>
<scope>runtime</scope>
</dependency>
`
to connect CDI with HK2 discovery mechanism.
Here is Official oracle Guideline
The default beans.xml discovery-mode (in Java EE 7) is "annotated". Which means only beans that have CDI annotations are recognized and managed by CDI.
Your AccountJob class is not annotated. If you want CDI to be able to inject the service into it then you need to annotate it with some scope annotation, e.g. #ApplicationScoped.
Your other option is to create CDI producer for creating AccountJob beans. See:
http://docs.jboss.org/weld/reference/latest/en-US/html_single/#_producer_methods

Retry OpmisticLockException with db-util library does not work

I have used this example to implement OptimisticLockException handling:
How to retry JPA transactions after an OptimisticLockException
Dependency in pom.xml:
<dependency>
<groupId>io.hypersistence</groupId>
<artifactId>hypersistence-utils-hibernate-55</artifactId>
<version>${hypersistence-utils.version}</version>
</dependency>
I have annotated the method which may receive OptimisticLockException:
#Retry(times = 10, on = OptimisticLockException.class)
public void modifySomething(){...}
However, when RollbackException/OptimisticLockException/StaleStateException occurs, I get a stack trace, but the method is not retried.
I use it with Guice 4.1.0. Should I bind it somewhere or write the method interceptor?
How to add AOP aspect?
You need to add the RetryAspect to your Spring configuration.
If you are using Guice, you have to create a similar Aspect because the one coming with Hypersistence Utils is only working with Spring.
In Spring, the configuration is very easy; you can do it like this:
#Configuration
#EnableAspectJAutoProxy
#ComponentScan(
basePackages = {
"io.hypersistence.utils.spring.aop"
}
)
public class RetryAspectConfiguration {
}

How to call a Spring managed object from a POJO?

I am running a web-app, which has one exposed class ( available to other POJO classes) and that has one autowired private member.
Spring managed class
public class EPSQueueSender {
#Autowired
private AmqpTemplate epsMessageTemplate;
public void dosomething(...){
epsMessageTemplate.convertAndSend(...); // Here epsMessageTemplate is null if instance of EPSQueueSender taken from other POJO
}
}
POJO class
public class Test{
EPSQueueSender sender = new EPSQueueSender();
sender.dosomething(....); // gives null exception on epsMessageTemplate
}
Spring code ( running as WebApp) and POJO class code( different Jar) are on same JVM. The POJO is not able to get initialized autowired object. However it is initialized if I use it in webApp project.
Can someone please give some suggestion how can I overcome this problem?
Last thing I would like to try is to hit webserver as http request from POJO.
beans can be pojo or xml many examples might help. You already have #autowired but you did not create the #bean method itself that belongs in a class annotated with #Configuration
Your problem could be overcome using #Configurable feature of spring. For it you have configure in xml with a code like belove
<context:annotation-config/>
<context:spring-configured/>
<context:load-time-weaver/>
in Java Congiguration like below:
#Configuration
#EnableAspectJAutoProxy
#EnableSpringConfigured
#EnableLoadTimeWeaving
public class ConfigApplicationContext {
}
with this configuration you can benefit of the load-waving aspect technique that througth the build-in Spring bean AnnotationBeanConfigureAspect you can inject Spring bean in a pojo that is annotated with #Configurable. you colud be have a code like below:
#Configurable
public class Test{
#Autowired
private EPSQueueSender sender;
public void method(){
sender.dosomething(....); // gives null exception on epsMessageTemplate
}
}
of course, since that you are using a load-wave technique you have configure an agent that will perform the istruments. the configuration is very simple and you have add a line like below in the start of the jvm or tomcat:
java -javaagent:path of the jar with the agent/spring-instrument.jar
remember of course of insert the aop and spring aop maven dependency:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>yourVersion</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>4
<version>yourVersion</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-instrument</artifactId>
<version>yourVersion</version>
</dependency>
I hope that this can help you

How to mock services with Arquillian?

Is it possible to use some kind of mocking framework with Arquillian, or precisely how to mock injected EJBs? I know that, with using the CDI (Contexts and Dependency Injection), it is possible to inject alternatives in test. But without CDI as injection mechanism, when I'm only using EJB injection, how this is possible?
Recently I have tested my EJBs with service interface mock implementation as following:
// Service inteface
public interface Audit {
void audit(String info);
}
// Mock implementation
#Stateless
public class MockAuditBean implements Audit {
public static String lastInfo = null;
#Override
public void audit(String info) {
this.lastInfo = info;
}
}
// assert in test
assertTrue(MockAuditBean.lastInfo.contains("dummy"));
This approach is possible but requires a lot of custom mock implementations. What is worse, injected instances of mocks are proxies and uses service interface. These can not be cast to mock implementation class to compare results. Only static members and methods of mock implementation can be used.
I have tested also another possibilities to set related EJBs manually. This approach has several draw-backs. It requires that target EJB of test has non-private members or setters for them. When target EJB relies on #PostConstruct lifecycle annotation, you have to call it after your manual "injection" setting.
Advantage of this solution is the ability to use mock frameworks, like mockito or jMock.
Have someone an experience to share, how to test and set-up such integration test, or even use mocking frameworks in it ?
IMO, EJBs where not designed with testing in mind. Your alternative sounds like a good enough compromise and I'd go for it. Using mockito is a major plus and I use it even when working with CDI.
I'd use the "default" member scope and javadoc to other developers access them for testing purposes only.
This article from Oracle shows an approach to "injecting" an EJB for testing using JUnit and Mockito:
http://www.oracle.com/technetwork/articles/java/unittesting-455385.html
Edit:
Basically the inclusion of Mockito allows for mocking objects like EntityManager etc.:
import static org.mockito.Mockito.*;
...
em = mock(EntityManager.class);
They show the approach for EJB as well using mockito. Given an EJB:
#Stateless
public class MyResource {
#Inject
Instance<Consultant> company;
#Inject
Event<Result> eventListener;
The test can "inject" those objects:
public class MyResourceTest {
private MyResource myr;
#Before
public void initializeDependencies(){
this.myr = new MyResource();
this.myr.company = mock(Instance.class);
this.myr.eventListener = mock(Event.class);
}
Note that MyResource and MyResource are in the same class path but different source folders so your tests have access to the protected fields, company and eventListener.
Edit:
Note: you can use FacesMockitoRunner from JBoss (https://community.jboss.org/thread/170800) to get this done for the common JSF components and use annotations for the others (Java EE 6 with CDI enabled as a pre-requisite for this, but does not require JBoss server):
Include jsf, mockito, and jsf-mockito dependencies in maven:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>1.9.5</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jboss.test-jsf</groupId>
<artifactId>jsf-mockito</artifactId>
<version>1.1.7-SNAPSHOT</version>
<scope>test</scope>
</dependency>
Add the #RunWith annotation to your test:
#RunWith(FacesMockitoRunner.class)
public class MyTest {
Inject common Faces objects using annotations:
#Inject
FacesContext facesContext;
#Inject
ExternalContext ext;
#Inject
HttpServletRequest request;
Mock any other objects using the annotations #org.mockito.Mock (it appears FacesMockitoRunner calls this behind the scenes so it may not be necessary here):
#Mock MyUserService userService;
#Mock MyFacesBroker broker;
#Mock MyUser user;
Init the Injected Mocks using the
#Before public void initMocks() {
// Init the mocks from above
MockitoAnnotations.initMocks(this);
}
Setup your test as usual:
assertSame(FacesContext.getCurrentInstance(), facesContext);
when(ext.getSessionMap()).thenReturn(session);
assertSame(FacesContext.getCurrentInstance().getExternalContext(), ext);
assertSame(FacesContext.getCurrentInstance().getExternalContext().getSessionMap(), ext.getSessionMap());
etc.
You may want to take a look at testfun-JEE which allows you to unit-test (not integration-test) your EJBs outside of a container.
testfun-JEE takes care for injecting EJBs as well as EntityManager and some standard resource directly into your test class - references within these EJBs to other EJBs are resolved automatically.
And the coolest thing is that you can mock any dependency by simple adding a member variable to your test annotated with #Mock - testfun-JEE will inject this mock wherever needed.
See examples in https://github.com/michaelyaakoby/testfun.
BTW, while this framework was published very recently (like today...) it is being widely used for over a year in my company.
Work with a framework, like Mockito.
Unfortunately, Arquillian does not automatically include the necessary dependencies.
You can add them in your #Deployment function:
#Deployment
public static WebArchive deploy()
{
return ShrinkWrap.create(WebArchive.class)
.addAsLibraries( // add maven resolve artifacts to the deployment
DependencyResolvers.use(MavenDependencyResolver.class)
.artifact("org.mockito:mockito-all:1.8.3")
.resolveAs(GenericArchive.class))
);
}
source
Then in your #Test method you could use:
mock(MockedService.class).methodName()
This github showcase shows a way to allow auto discovery, which seems to require some setup:
source
If you really want to interact with mocks in your integration tests (for instance one reason might be that you don't have a full blown implementation yet or you have an facade to external systems which you don't have control over), there is quite an easy way to integrate Mockito with your Arquillian tests, have a look at this example from the showcase. It's actually extension on its own, but not released as one.

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