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Prevent to start spring-boot application if enum valitiation fails

I want to prevent my application from starting if my enum method for validation uniqueness of a field fails.
public enum MyEnum {
VALUE_1(1),
VALUE_2(1), //same code as VALUE_1 is forbidden
VALUE_3(3),
;
private int code;
static { //this method is called only when 1st time acessing an inscance of this enum, I want it to be executed upon spring boot initialization and when it fails stop appliacation
long uniqueCodesCount = Arrays.stream(MyEnum.values()).map(MyEnum::getCode)
.distinct()
.count();
if (MyEnum.values().length != uniqueCodesCount) {
throw new RuntimeException("Not unique codes");
}
}
}

Just keep it simple. For example convert the verification to a static method:
public enum MyEnum {
...
public static void verifyUniqueness() {
long uniqueCodesCount = Arrays.stream(MyEnum.values()).map(MyEnum::getCode)
.distinct()
.count();
if (MyEnum.values().length != uniqueCodesCount) {
throw new RuntimeException("Not unique codes");
}
}
}
Then you may implement InitializingBean in a bean and override the method afterPropertiesSet(). E.g. suppose your application is called DemoApplication, it will look like this:
#SpringBootApplication
public class DemoApplication implements InitializingBean {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
#Override
public void afterPropertiesSet() throws Exception {
MyEnum.verifyUniqueness();
}
}
From the documentation of InitializingBean:
Interface to be implemented by beans that need to react once all their properties have been set by a BeanFactory: e.g. to perform custom initialization, or merely to check that all mandatory properties have been set.

How can I manage (or pass as an argument) my config json to start the testing of my vertx application?

I have a small vertx application with an AppLauncher class that extend of VertxCommandLauncher and I set a appConfig.json with the typical config parameters :
public class AppLauncher extends VertxCommandLauncher implements VertxLifecycleHooks {
public static void main(String[] args) {
new AppLauncher().dispatch(args);
}
#Override
public void afterConfigParsed(JsonObject config) {
AppConfig.INSTANCE.setConfig(config);
}
To run my application in my IDE I put in edit configuration my main class (Applauncher.java) and the arguments :
run io.vertx.covid.verticle.MainVerticle -conf../vertx-application/src/main/resources/appConfig.json
This is my test class:
#BeforeAll
static void deployVerticles(Vertx vertx, VertxTestContext testContext) {
vertx.deployVerticle(BaseVerticle.class.getName(),testContext
.succeeding(id->testContext.completeNow()));
}
This is my BaseVerticle class that all my verticles extends from:
public abstract class BaseVerticle extends AbstractVerticle {
public static String CONTEXT_PATH = AppConfig.INSTANCE.getConfig().getString(Constants.CONTEXT_PATH);
}
And this is my AppConfig class :
public enum AppConfig {
INSTANCE;
private JsonObject config;
public JsonObject getConfig() {
return config;
}
public void setConfig(JsonObject config) {
this.config = config;
}
}
Everything works, but if I would like to test it in a separete way then I deploy my verticles but I have a Nullpointer in the CONTEXT_PATH (BaseVerticle class) because the config (suppose to be taken from appConfig.json) is null.
I haven't found a way to pass the arguments with my appConfig.json or should I call to the main method passing the arguments?

I like to do something that is similar to profiles in my vertx application.
If you set an environment variable with the key vertx-config-path before the vertx instance is initialized, you can control where vertx's config retriever (you might need to add vert-config to your gradle/maven dependencies) gets the configuration from.
In your launcher, you can do something like the following, which will give you the ability to add profile based config files to your resources folder conf/config-%s.json where %s is the profile name:
public class CustomLauncher extends Launcher {
public static final String ACTIVE_PROFILE_PROPERTY = "APP_ACTIVE_PROFILE";
private static final CLI cli = CLI.create("main")
.addOption(new Option()
.setShortName("p")
.setLongName("profile")
);
public static void main(String[] args) {
initDefaults(Arrays.asList(args));
new CustomLauncher().dispatch(args);
}
public static void executeCommand(String cmd, String... args) {
initDefaults(Arrays.asList(args));
new CustomLauncher().execute(cmd, args);
}
public static void initDefaults(List<String> args) {
System.setProperty(LoggerFactory.LOGGER_DELEGATE_FACTORY_CLASS_NAME, SLF4JLogDelegateFactory.class.getName());
CommandLine parse = cli.parse(args);
String profile = parse.getOptionValue("p");
if (profile != null && !profile.isEmpty()) {
System.setProperty(ACTIVE_PROFILE_PROPERTY, profile);
System.setProperty("vertx-config-path", String.format("conf/config-%s.json", profile));
}
}
}
Then in your test, instead of relaying on vertx test extension to inject vertx for you, you can initialize it by yourself and control the profile (aka which config file to load) like the following:
private static Vertx vertx;
#BeforeAll
public static void deployVerticles(VertxTestContext testContext) {
CustomLauncher.initDefaults(Arrays.asList("--profile", "test"))
vertx = Vertx.vertx();
ConfigRetriever.create(vertx).getConfig(asyncResult -> {
if (asyncResult.succeeded()) {
JsonObject config = asyncResult.result();
DeploymentOptions deploymentOptions = new DeploymentOptions()
.setConfig(config);
vertx.deployVerticle(BaseVerticle.class.getName(), deploymentOptions);
} else {
// handle failure
}
});
}
Then when you run your application, instead of providing -conf, you can use -p or --profile
I also highly recommend to get familiar with vertx-config as you can also get env variables, k8s config maps, and much more.
EDIT: I also highly recommend to move to Kotlin if possible, makes the async-code much easier to handle in an imperative way (with Coroutines). It's very hard to deal with libraries like Vert.x in Java compared to languages like Kotlin.

I solved my problem creating a verticle with the config stuffs (vertx-config documentation), here is my verticle config class:
public class ConfigVerticle extends AbstractVerticle {
protected static Logger logger = LoggerFactory.getLogger(ConfigVerticle.class);
public static JsonObject config;
#Override
public void start() throws Exception {
ConfigStoreOptions fileStore = new ConfigStoreOptions()
.setType("file")
.setOptional(true)
.setConfig(new JsonObject().put("path", "conf/appConfig.json"));
ConfigStoreOptions sysPropsStore = new ConfigStoreOptions().setType("sys");
ConfigRetrieverOptions options = new ConfigRetrieverOptions().addStore(fileStore).addStore(sysPropsStore);
ConfigRetriever retriever = ConfigRetriever.create(vertx, options);
retriever.getConfig(ar -> {
if (ar.failed()) {
logger.info("Failed to retrieve config from appConfig.json");
} else {
config = ar.result();
vertx.deployVerticle(MainVerticle.class.getName(), new DeploymentOptions().setConfig(config));
}
});
}
}
And my MainVerticle.class I pass the new configuration like this:
public class MainVerticle extends AbstractVerticle {
#Override
public void start(){
vertx.deployVerticle(BackendVerticle.class.getName(), new DeploymentOptions().setConfig(config()));
}
}
Then, my simpleTests :
#ExtendWith(VertxExtension.class)
public class BaseCovidTest {
protected WebClient webClient;
#BeforeEach
void initWebClient(Vertx vertx){
webClient = WebClient.create(vertx);
}
#BeforeAll
static void deployVerticles(Vertx vertx, VertxTestContext vertxTestContext) {
vertx.deployVerticle(ConfigVerticle.class.getName() ,vertxTestContext
.succeeding(id-> {
try {
vertxTestContext.awaitCompletion(1, TimeUnit.SECONDS);
} catch (InterruptedException e) {
e.printStackTrace();
}
vertxTestContext.completeNow();
}));
}
}
And everything works, thanks #Tom that inspired me to fix it!

Java - How to test exception which never will occur?

I have Utils class with method which throws exception when given data are incorrect.
I have also Service which uses this method, but the data are always generated in way that they will be correct during call. Data are generated by another utils class.
I understand that I should throw this exception from Utils class - but I can't throw it from Service - so I have to catch it.
How can I test this, simulate this exception?
All actions on this data are in private methods.
I want to avoid PowerMock, because I heard that it's a sign of bad design.
So the question is, how to implement this in good design?

From your description it looks like this:
class Service {
public void someMethod() {
Data data = AnotherUtils.getData();
try {
Utils.method(data); // exception never thrown
} catch(Exception e) {
// how to test this branch?
}
}
}
The goal would be something like this:
interface DataProvider {
Data getData();
}
interface DataConsumer {
void method(Data data);
}
class Service {
private final DataProvider dataProvider;
private final DataConsumer dataConsumer;
public Service(DataProvider dataProvider, DataConsumer dataConsumer) {...}
public void someMethod() {
Data d = dataProvider.getData();
try {
dataConsumer.method(data);
} catch(Exception e) {
}
}
}
This technique is called dependency injection.
Then, when testing, you can simply provide a mock implementation for this DataProvider interface that does return faulty data:
#Test(expected=Exception.class)
public void myTest() {
DataProvider badDataProvider = () -> new BadData(); // Returns faulty data
Service service = new Service(badDataProvider, Utils.getConsumer());
service.someMethod(); // boom!
}
For the non-testing code, you could simply wrap the utils classes you already have in these interfaces:
class AnotherUtils {
public static Data getData() {...}
public static DataProvider getProvider() {
return AnotherUtils::getData;
}
}
...
Service service = new Service(AnotherUtils.getProvider(), Utils.getConsumer());

Here is an approach where you want to introduce Dependency Injection, but for whatever reason you don't want to change legacy code.
Say you have some static utility method like so:
class Utils{
public static Something aMethod(SomethingElse input) throws AnException{
if(input.isValid())
return input.toSomething();
throw new AnException("yadda yadda");
}
}
And you have a class that uses that utility method. You can still inject it with a FunctionalInterface.
#FunctionalInterface
interface FunctionThrowsAnException<K,V> {
V apply(K input) throws AnException;
}
class Service {
private final FunctionThrowsAnException<SomethingElse,Something> func;
Service(FunctionThrowsAnException<SomethingElse,Something> func){
this.func = func;
}
Something aMethod(SomethingElse input){
try{
return func.apply(input);
}catch(AnException ex){
LOGGER.error(ex);
}
}
}
Then use it like this:
new Service(Utils::aMethod).aMethod(input);
To test it:
new Service(x -> { throw new AnException("HA HA"); }).aMethod(input);

junit - how to mock field in real class?

I have a tricky situation. I am using MVP architecture for android but thats not important. I have a class called DoStandardLoginUsecase that basically just connects to a server with login info and gets a access token. i am trying to test it. But the problem is the context that i am passing in to it so i can initialize dagger.
public class DoStandardLoginUsecase extends BaseUseCase {
#Inject
UserDataRepository mUserDataRepo;
private StandardLoginInfo loginInfo;
public DoStandardLoginUsecase(Context context) {
/* SEE HERE I AM USING A APPLICATION CONTEXT THAT I PASS TO DAGGER
*/
((MyApplication)context).getPresenterComponent().inject(this);
}
#Override
public Observable<Login> buildUseCaseObservable() {
return mUserDataRepo.doStandardLogin(loginInfo);
}
public void setLoginInfo(StandardLoginInfo loginInfo) {
this.loginInfo = loginInfo;
}
}
and here is the test i have so far:
public class DoStandardLoginUsecaseTest {
DoStandardLoginUsecase standardLoginUsecase;
StandardLoginInfo fakeLoginInfo;
TestObserver<Login> subscriber;
MockContext context;
#Before
public void setUp() throws Exception {
//now when i create the object since its a mock context it will fail when it tries to call real things as these are stubs. So how do i test this object. how do i create an instance of this object ? I am willing to use [daggerMock][1] if that helps also.
standardLoginUsecase = New DoStandardLoginUsecase(context);
fakeLoginInfo = new StandardLoginInfo("fred#hotmail.com","Asdfgh4534");
subscriber = TestObserver.create();
}
#Test
public void buildUseCaseObservable(){
standardLoginUsecase.seLoginInfo(fakeLoginInfo);
standardLoginUsecase.buildUseCaseObservable().subscribe(subscriber);
subscriber.assertNoErrors();
subscriber.assertSubscribed();
subscriber.assertComplete();
}
}

I would do the test like this:
public class DoStandardLoginUsecaseTest {
private DoStandardLoginUsecase target;
private MyApplication contextMock;
#Before
public void beforeEach() {
contextMock = Mockito.mock(MyApplication.class);
// Note that you need to mock the getPresenterComponent
// but I don't know what it returns.
target = new DoStandardLoginUsecase(contextMock);
}
#Test
public void buildUseCaseObservable() {
UserDataRepository userDataMock = Mockito.mock(UserDataRepository.class);
StandardLoginInfo loginInfoMock = Mockito.mock(StandardLoginInfo.class);
target.mUserDataRepo = userDataMock;
target.setLoginInfo(loginInfoMock);
Observable<Login> expected = // create your expected test data however you like...
Mockito.when(userDataMock.doStandardLogin(loginInfoMock)).thenReturn(expected);
Observable<Login> actual = target.buildUseCaseObservable();
Assert.areSame(actual, expected);
}
}

Mock another method in SWF Workflow Client

I am trying to write a unit test for a AWS SWF workflow. Below is the code I would like to Test
#Override
public void execute(String abc) {
new TryCatch() {
#Override
protected void doTry() throws Throwable {
Promise<SomeObject> temp = activityClient.action(abc);
again(temp, abc);
}
#Override
protected void doCatch(Throwable e) throws Throwable {
throw new RuntimeException(e);
}
};
}
#Asynchronous
public void again(Promise<SomeObject> someObject, String abc) {
// Do Something
}
My Test class is as below:
public class SomeWorkflowTest extends AbstractTestCase {
#Rule
public WorkflowTest workflowTest = new WorkflowTest();
List<String> trace;
private SomeWorkflowClientFactory workflowFactory = new SomeWorkflowClientFactoryImpl();
#Before
public void setUp() throws Exception {
trace = new ArrayList<String>();
// Register activity implementation to be used during test run
SomeActivitiesImpl activitiesImpl = new SomeActivitiesImpl() {
#Override
public SomeObject performHostRecovery(String abc) {
trace.add("ABC: " + abc);
SomeObject testObject = new SomeObject();
return testObject;
}
};
workflowTest.addActivitiesImplementation(activitiesImpl);
workflowTest.addWorkflowImplementationType(SomeWorkflowImpl.class);
}
#Test
public void testWorkflowExecutionCall() throws Throwable {
SomeWorkflowClient workflow = workflowFactory.getClient("XZY");
workflow.execute("XYZ");
List<String> expected = new ArrayList<String>();
expected.add("ABC: abc");
AsyncAssert.assertEqualsWaitFor("Wrong Wrong", expected, trace, null);
}
}
I have used SWF Testing Docs to write above test class. However the method that I am testing (execute()) is invoking another method in same class. I am not concerned with the execution of internal method and would like to mock it out, but given the way the workflow class object is instantiated, I am not clear on how to mock the inner method.
Can someone please point out on this?
Thanks

You actually can instantiate a workflow object or any other object that workflow uses inside the test method:
#Test
public void testWorkflowExecutionCall() throws Throwable {
SomeWorkflow workflow = new SimpleWorkflow(...);
workflow.execute("XYZ");
List<String> expected = new ArrayList<String>();
expected.add("ABC: abc");
AsyncAssert.assertEqualsWaitFor("Wrong Wrong", expected, trace, null);
}
It works because WorkflowTest executes test methods in the context of a dummy test workflow. The code
SomeWorkflowClient workflow = workflowFactory.getClient("XZY");
workflow.execute("XYZ");
actually creates a child workflow in the context of this dummy workflow. But nothing prevents you from executing any async code directly without creating the child workflow.