I want to load Spring initial context inside a AWS lambda handler class. This class is the starting point of my application. I did it in the below way.
#SpringBootApplication
public class LambdaFunctionHandler implements RequestHandler<KinesisEvent, Object> {
#Override
public Object handleRequest(KinesisEvent input, Context context) {
AnnotationConfigApplicationContext appContext = new AnnotationConfigApplicationContext(LambdaFunctionHandler.class);
LambdaFunctionHandler lambdaHandlerBean = appContext.getBean(LambdaFunctionHandler.class);
// some business logic call
return null;
}
}
This is working fine but I'm getting warning on appContext that it should be closed as it is resource leak. this can be fixed by calling appContext.close() but my doubt is whether this way of initializing Spring application context in a non main method is correct ? Most recommended way to do in a main method is like below
SpringApplication app = new SpringApplication(LambdaFunctionHandler.class);
ConfigurableApplicationContext context = app.run(args);
LambdaFunctionHandler lambdaFunctionHandler =
context.getBean(LambdaFunctionHandler.class);
But I don't have the value to replace the args in my case. can anyone suggest the right way of doing this
You can simple class with main method for #SpringBootApplication and
use CommandLineRunner for loading AWS lambda handler. Just implement the run to load the bean
https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/CommandLineRunner.html
Related
I came across an interesting article: AOP Aspects as mocks in JUnit
Since I have requirement to mock multiple final and private static variables, I am planning to use AOP in place of reflection or PowerMockito as they are causing issues with SpringJUnit4ClassRunner.
Is there any way I can use #Aspect for test classes without using the annotation #EnableAspectJAutoProxy? (I want to use an aspect targeting class X only in one test case.)
This is a sample of what I want to do.
The question is answered(adding for discussion on what could be done)
//External class
public final class ABC(){
public void method1() throws Exception {}
}
#Service
public void DestClass() {
private static final ABC abc = new ABC();
public Object m() {
// code (...)
try {
abc.method1();
}
catch(Exception e) {
// do something (...)
return null;
}
// more code (...)
}
}
Spring framework allows to programmatically create proxies that advise target objects , without configuring through #EnableAspectJAutoProxy or <aop:aspectj-autoproxy>
Details can be found in the documentation section : Programmatic Creation of #AspectJ Proxies and the implementation is pretty simple.
Example code from the documentation.
// create a factory that can generate a proxy for the given target object
AspectJProxyFactory factory = new AspectJProxyFactory(targetObject);
// add an aspect, the class must be an #AspectJ aspect
// you can call this as many times as you need with different aspects
factory.addAspect(SecurityManager.class);
// you can also add existing aspect instances, the type of the object supplied must be an #AspectJ aspect
factory.addAspect(usageTracker);
// now get the proxy object...
MyInterfaceType proxy = factory.getProxy();
Please note that with Spring AOP , only method executions can be adviced. Excerpt from the documentation
Spring AOP currently supports only method execution join points
(advising the execution of methods on Spring beans). Field
interception is not implemented, although support for field
interception could be added without breaking the core Spring AOP APIs.
If you need to advise field access and update join points, consider a
language such as AspectJ.
The document shared with the question is about aspectj and without providing the sample code to be adviced it is hard to conclude if the requriement can acheived through Spring AOP. The document mentions this as well.
One example of the integration of AspectJ is the Spring framework,
which now can use the AspectJ pointcut language in its own AOP
implementation. Spring’s implementation is not specifically targeted
as a test solution.
Hope this helps.
--- Update : A test case without using AOP ---
Consider the external Class
public class ABCImpl implements ABC{
#Override
public void method1(String example) {
System.out.println("ABC method 1 called :"+example);
}
}
And the DestClass
#Service
public class DestClass {
private static final ABC service = new ABCImpl();
protected ABC abc() throws Exception{
System.out.println("DestClass.abc() called");
return service;
}
public Object m() {
Object obj = new Object();
try {
abc().method1("test");
} catch (Exception e) {
System.out.println("Exception : "+ e.getMessage());
return null;
}
return obj;
}
}
Following test class autowires the DestClass bean with overridden logic to throw exception . This code can be modified to adapt to your requirement.
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = { DestClassSpringTest.TestConfiguration.class })
public class DestClassSpringTest {
#Configuration
static class TestConfiguration {
#Bean
public DestClass destClass() {
return new DestClass() {
protected ABC abc() throws Exception {
// super.abc(); // not required . added to demo the parent method call
throw new Exception("Custom exception thrown");
}
};
}
}
#Autowired
DestClass cut;
#Test
public void test() {
Object obj = cut.m();
assertNull(obj);
}
}
Following will be the output log
DestClass.abc() called // this will not happen if the parent method call is commented in DestClassSpringTest.TestConfiguration
Exception : Custom exception thrown
The article you are referring to is using full AspectJ, not Spring AOP. Thus, you do not need any #EnableAspectJAutoProxy for that, just
either the AspectJ load-time weaver on the command line when running your test via -javaagent:/path/to/aspectjweaver.jar
or the AspectJ compiler activated when compiling your tests (easily done via AspectJ Maven plugin if you use Maven)
Both approaches are completely independent of Spring, will work in any project and even when using Spring also work when targeting execution of third party code because no dynamic proxies are needed unlike in Spring AOP. So there is no need to make the target code into a Spring bean or to create a wrapper method in your application class for it. When using compile-time weaving you can even avoid weaving into the third party library by using call() instead of execution() pointcut. Spring AOP only knows execution(), AspectJ is more powerful.
By the way: Unfortunately both your question and your comment about the solution you found are somewhat fuzzy and I do not fully understand your requirement. E.g. you talked about mocking final and private static variables, which would also be possible in other ways with AspectJ by using set() and/or get() pointcuts. But actually it seems you do not need to mock the field contents, just stub the results of method calls upon the objects assigned to those fields.
When using spring-data-rest there is a post processing of Resource classes returned from Controllers (e.g. RepositoryRestControllers). The proper ResourceProcessor is called in the post processing.
The class responsible for this is ResourceProcessorHandlerMethodReturnValueHandler which is part of spring-hateoas.
I now have a project that only uses spring-hateoas and I wonder how to configure ResourceProcessorHandlerMethodReturnValueHandler in such a scenario. It looks like the auto configuration part of it still resides in spring-data-rest.
Any hints on how to enable ResourceProcessorHandlerMethodReturnValueHandler in a spring-hateoas context?
I've been looking at this recently too, and documentation on how to achieve this is non-existent. If you create a bean of type ResourceProcessorInvokingHandlerAdapter, you seem to lose the the auto-configured RequestMappingHandlerAdapter and all its features. As such, I wanted to avoid using this bean or losing the WebMvcAutoConfiguration, since all I really wanted was the ResourceProcessorHandlerMethodReturnValueHandler.
You can't just add a ResourceProcessorHandlerMethodReturnValueHandler via WebMvcConfigurer.addReturnValueHandlers, because what we need to do is actually override the entire list, as is what happens in ResourceProcessorInvokingHandlerAdapter.afterPropertiesSet:
#Override
public void afterPropertiesSet() {
super.afterPropertiesSet();
// Retrieve actual handlers to use as delegate
HandlerMethodReturnValueHandlerComposite oldHandlers = getReturnValueHandlersComposite();
// Set up ResourceProcessingHandlerMethodResolver to delegate to originally configured ones
List<HandlerMethodReturnValueHandler> newHandlers = new ArrayList<HandlerMethodReturnValueHandler>();
newHandlers.add(new ResourceProcessorHandlerMethodReturnValueHandler(oldHandlers, invoker));
// Configure the new handler to be used
this.setReturnValueHandlers(newHandlers);
}
So, without a better solution available, I added a BeanPostProcessor to handle setting the List of handlers on an existing RequestMappingHandlerAdapter:
#Component
#RequiredArgsConstructor
#ConditionalOnBean(ResourceProcessor.class)
public class ResourceProcessorHandlerMethodReturnValueHandlerConfigurer implements BeanPostProcessor {
private final Collection<ResourceProcessor<?>> resourceProcessors;
#Override
public Object postProcessAfterInitialization(Object bean, String beanName)
throws BeansException {
if (bean instanceof RequestMappingHandlerAdapter) {
RequestMappingHandlerAdapter requestMappingHandlerAdapter = (RequestMappingHandlerAdapter) bean;
List<HandlerMethodReturnValueHandler> handlers =
requestMappingHandlerAdapter.getReturnValueHandlers();
HandlerMethodReturnValueHandlerComposite delegate =
handlers instanceof HandlerMethodReturnValueHandlerComposite ?
(HandlerMethodReturnValueHandlerComposite) handlers :
new HandlerMethodReturnValueHandlerComposite().addHandlers(handlers);
requestMappingHandlerAdapter.setReturnValueHandlers(Arrays.asList(
new ResourceProcessorHandlerMethodReturnValueHandler(delegate,
new ResourceProcessorInvoker(resourceProcessors))));
return requestMappingHandlerAdapter;
}
else return bean;
}
}
This has seemed to work so far...
I'm attempting to use Unity to inject a dependency per this article:
http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver
Here is what I have in my global.asax
void ConfigureApi(HttpConfiguration config)
{
var unity = new UnityContainer();
unity.RegisterType<CustomerController>();
unity.RegisterType<TPS.Data.Can.IUnitOfWork, TPS.Data.Can.EFRepository.UnitOfWork>(new HierarchicalLifetimeManager());
config.DependencyResolver = new IoCContainer(unity);
}
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
ConfigureApi(GlobalConfiguration.Configuration);
}
Here is my API controller:
public class CustomerController : ApiController
{
private TPS.Data.Can.IRepository<tblCustomer> _repo;
private TPS.Data.Can.IUnitOfWork _uow;
public CustomerController() { }
public CustomerController(TPS.Data.Can.IUnitOfWork uow) {
_uow = uow;
_repo = uow.CustomerRepository;
}
// GET api/customer/5
public IEnumerable<Customer> Get()
{
string identity = HttpContext.Current.User.Identity.Name;
//REFACTOR THIS
if (String.IsNullOrWhiteSpace(identity))
identity = "chardie";
var customers = from c in _repo.Get()
where c.SalesRep == identity
select new Customer
{
IDCUST = null,
CustCode = c.CustCode,
CustName = c.CustName
};
return customers.ToList();
}
This works when I first start debugging my application. If I set a breakpoint in the parameterized constructor, the breakpoint will be hit when I hit the Web API for the first time. When I hit refresh in my browser, the constructor does not get called, the dependency doesn't get injected, and the Get() action throws an exception because the expected repository is null.
Can anyone tell me why my constructor isn't being called after the first request?
Thanks!
Chris
EDIT
FWIW, I removed the parameterless constructor entirely from the Web API controller, and on my second request to it, I get the exception:
Type 'TPS.Website.Api.CustomerController' does not have a default constructor
So it appears I'm getting my repo dependency injected on the first request, but after that every instantiation of the Web API controller is done through the parameterless constructor.
You're not specifying a lifecycle for the controller. MSDN states
If you do not specify a value for the lifetime, the instance will have
the default container-controlled lifetime. It will return a reference
to the original object on each call to Resolve.
If the IUnitOfWork dependency is transient, then the controller should be transient too. So try
unity.RegisterType<CustomerController>(new TransientLifetimeManager());
This might not solve the whole problem but it sounds like part of it. You certainly shouldn't need the parameterless constructor.
I had this as I was returning my resolver for my dependency scope using this and then disposing the container in the dispose. So after the first request the container was disposed.
Looks like it's because you're not using singleton pattern for the Unity Container.
Have a private static variable instead of the var container = new UnityContainer();
internal static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() => new UnityContainer());
Then access within code using the .Value property.
I've got my application setup to use CDI and all is going well. Now I'm creating a new bean that extends a class from a 3rd party library. I attempted to create something like the below example:
#Named("myNewClass")
#ConversationScoped
public class MyNewClass extends ThirdPartyClass {
#Inject
private ApplicationConfig applicationConfig;
#Override
public void doStuff() {
// In this code, applicationConfig will be null.
}
}
When doStuff is called, applicationConfig was always null. I added a no args constructor & a method tagged with #PostConstruct to try and see what was going on. The constructor gets called then the doStuff method. As doStuff is being called at construction time I cannot use the #Inject annotations at this point.
So my question is how do I get a hold of applicationConfig at this point?
I've been tinkering with BeanManager (this is in a function I call with ApplicationConfig.class as a parameter):
Context initCtx = new InitialContext();
Context envCtx = (Context) initCtx.lookup("java:comp/env");
BeanManager beanManager = (BeanManager) envCtx.lookup("BeanManager");
Bean myBean = beanManager.getBeans(clazz).iterator().next();
return beanManager.getReference(myBean, clazz, beanManager.createCreationalContext(myBean));
Which works but it's creating a new ApplicationConfig instance. I want to get the one that I know already exists on my ConversationScope.
A little info: I'm using Seam 3.0, Weld Servlet 1.1.1 and this is running on Tomcat 6.
You can annotate a constructor with #Inject then any parameters of the constructor become injection points which the BeanManager will resolve. It's certainly not the desired way of doing it, but if it works for you, go for it.
My app has a ProviderFactory static class that has static utility methods passing back static instances of things like a logger. The rest of my app then can just grab a/the reference to the logger from anywhere without having to pass in the logger (common design practice).
So, another part of my app, the DbCacheProvider, has methods that make calls to the logger so internally it gets a reference to the logger from the factory and then issues calls to it.
My question is that using Moq, I want to verify methods on the logger are being called by the methods within the DbCacheProvider. I can do this using dependency injection when I pass a mock logger into the DbCacheProvider as a parameter, but I'm not passing the logger in (not do I want to). So, how would I verify the DbCacheProvider is making calls to the logger?
If you don't want to pass the logger in through the constructor you'd need to change your ProviderFactory while running unit tests to return your mocked logger.
Anyway there are a couple of reasons it's often suggested to set up dependency injection:
Your tests are more straightforward and don't involve finagling with custom factories
IoC frameworks like Unity, Ninject and Autofac make it easy to create objects when their dependencies are set up this way. If you set up all of your objects this way, the framework will do all the heavy lifting of creating the right objects and passing them in for you. The dependency injection is done automatically and won't be a burden for you.
Old question without an answer, I had a similar problem and solved it like this:
I have the following sample code and need to verify that not only was a method called but was called with a specific value.
public interface ILog
{
void Info(string message);
}
public interface ILogFactory
{
ILog GetLogger();
}
This is the class being tested, where the interface items are being injected:
public class NewAction
{
readonly ILogFactory _logger;
public NewAction(ILogFactory logger)
{
_logger = logger;
}
public void Step1()
{
_logger.GetLogger().Info("Step 1");
}
public void Step2()
{
_logger.GetLogger().Info("Step 2");
}
}
This is obviously a very simplistic view of my actual code, but I needed to verify that Step1 and Step2 are behaving as expected and passed the correct values to the Log, this would mean I also needed to ensure they occurred in the right order. My test:
[TestClass]
public class UnitTest1
{
[TestMethod]
public void TestMethod1()
{
// Arrange
var log = new Mock<ILog>();
var factory = new Mock<ILogFactory>();
factory.Setup(l => l.GetLogger()).Returns(log.Object);
// Act
var action = new NewAction(factory.Object);
action.Step1();
action.Step2();
// Assert
factory.Verify(l => l.GetLogger());
log.Verify(l => l.Info(It.Is<string>(s => s == "Step 1")));
log.Verify(l => l.Info(It.Is<string>(s => s == "Step 2")));
}
}
Hope this helps.