Spring-Boot #Autowired variable is null - java

I'm trying to get a repository into a class annotated with #Service using the #Autowired annotation in a Spring-boot class. However, the repository turns up as a null.
Here's the relevant code:
#Service
public class ImportLicenses {
#Autowired
private LicenseRepository licenseRepository;
public static void main (String[] args) {
ImportLicenses importLicenses = new ImportLicenses();
importLicenses.listFiles("/Users/admin/Licenses/licenses");
}
private void processLicense (Path path) {
try {
count++;
BasicFileAttributes attr = Files.readAttributes(path, BasicFileAttributes.class);
FileTime fileTime = attr.lastModifiedTime();
Permission permission = new Permission(readLineByLineJava8(path.toFile().getAbsolutePath()));
LicensePojo licensePojo = new LicensePojo(permission, path);
Optional<License> licenseOptional = licenseRepository.findById(licensePojo.getId());
at which point it gets an NPE since licenceReposity is null.
I am able to access the licenseRepository in a controller class with this constructor
public LicenseController(LicenseRepository licenseRepository,
UserRepository userRepository) {
this.licenseRepository = licenseRepository;
this.userRepository = userRepository;
}
However, since I'm calling the constructor directly in the static main method, this doesn't seem like it's available. What's the best way to get the repository into this class?
Edit: Thanks for the responses. To clarify the question, I'm trying to pull this class into the structure of the existing Spring Boot application, instead of creating a separate one.
Option 1: Create a button or menu selection on the UI, and create a new controller class to run the import. This would be the simplest, but I don't want to necessarily have that on the UI.
Option 2: Code the import class create another Spring Application
#SpringBootApplication
public class ImportLicenses implements ApplicationRunner {
private final Logger logger = LoggerFactory.getLogger(LicenseGenApplication.class);
#SpringBootApplication
public static void main() {
main();
}
public static void main(String[] args) {
SpringApplication.run(ImportLiceneses.class, args);
}
#Override
public void run(ApplicationArguments args) throws Exception {
listFiles("/Users/admin//licenses");
}
public void listFiles(String path) {
try {
Files.walk(Paths.get(path))
.filter(ImportLicenses::test)
.forEach(p -> processLicense(p));
} catch (IOException e) {
e.printStackTrace();
}
}
....
}
Option 3 - Create a non-executable jar file from the existing application for use in the new application to avoid duplicating code.
Option 1 is the quickest, I'm not sure if option 2 work, Option 3 I'll take a look at to see if it's do-able.

Your application is a usual Java application. It is not a Spring Boot application.
What should you do? Make a Spring Boot application of it. For instance, create a demo app at https://start.spring.io/, compare your main class to the main class in the demo application, then adjust your main class correspondingly. Also compare your Maven or Gradle config to the config of the demo app and adjust correspondingly.
At least, your application should have an annotation #SpringBootApplication. Also, it should be launched via SpringApplication.run(...). This is a minimum. Depending on what you need, you may want to use #EnableAutoConfiguration and other configuration options.

Related

Spring Boot Integration Testing - Mocking #Service before Application Context Starts?

I have to create a integration test for a microservice X which downloads, processes and importing csv files from external sftp servers. The whole process is started by a spring boot scheduler task which starts a spring batch job for processing and importing the data. The import process is done by the spring batch writer, which is a restTemplate Repository (so it calls post requests to another microservice Y).
I already managed to mock the sftp server, putting a test file on it and the current integration test is downloading the file. (https://github.com/stefanbirkner/fake-sftp-server-rule/)
My problem is, that the task will be scheduled immediately when the application context starts so there is no trigger like a api call. To get the whole integration test working i have to mock the part where the external microservice Y is called through a restTemplate call. This repository is called in the spring batch writer and this repository is created by a repositoryFactory which is a #Service. The repositoryFactory is injected in the spring batch configuration class.
I already tried to use the #MockBean annotation in the test class as well as in a separate test configuration where i am mocking the create() function of the factory to deliver a repository mock. But at some point it does not work and it delivers still the original object which leads to interupt the import job.
I also tried to use the WireMock library, but also in this case it does not catched any api calls and at some point leads to interrupt the sftp socket. (?)
I hope someone could help me out.
The current test:
#NoArgsConstructor
#RunWith(SpringRunner.class)
#SpringBootTest(classes = Application.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
#ContextConfiguration(classes = {JsonHalConfig.class})
#TestPropertySource(locations = "classpath:application-test.properties")
#TestMethodOrder(MethodOrderer.MethodName.class)
public class ImportIT {
#ClassRule
public static final FakeSftpServerRule sftpServer = new FakeSftpServerRule();
private static final String PASSWORD = "password";
private static final String USER = "username";
private static final int PORT = 14022;
#BeforeClass
public static void beforeClass() throws IOException {
URL resource = getTestResource();
if (resource != null) {
sftpServer.setPort(PORT).addUser(USER, PASSWORD);
sftpServer.createDirectories("/home/username/it-space/IMPORT", "/home/username/it-space/EXPORT");
sftpServer.putFile("/home/username/it-space/IMPORT/INBOX/testFile.csv",
resource.openStream());
} else {
throw new IOException("Failed to get test resources");
}
}
private static URL getTestResource() {
return ImportIT.class.getClassLoader().getResource("testFile.csv");
}
#Test
public void test_A_() throws IOException, RepositoryException {
assertTrue(true);
}
}
I tried following configuration classes
(included in #ContextConfiguration)
#Configuration/#TestConfiguration
public class RepositoryTestConfig {
#Bean
#Primary
public IRepositoryFactory repositoryFactory() {
IRepositoryFactory repositoryFactory = mock(IRepositoryFactory.class);
IRepository repository = mock(IRepository.class);
when(repositoryFactory.create(anyString())).thenReturn(repository);
return repositoryFactory;
}
}
(as static class in the test class)
#TestConfiguration/#Configuration
public static class RepositoryTestConfig {
#MockBean
private IRepositoryFactory repositoryFactory;
#PostConstruct
public void initMock(){
IRepository repository = mock(IRepository.class);
Mockito.when(repositoryFactory.create(anyString())).thenReturn(
repository
);
}
}
UPDATE 27.08.2021
I have a RestConfig #Component where a new RestTemplateBuilder is created. I tried to #MockBean this component to deliver a RestTemplateBuilder Mock and injected a MockRestServiceServer object to catch outgoing api calls. But unfortunately it does not work as aspected. Am i missing something? I also tried to create a "TestRestController" to trigger the scheduling of the task but it never delivers the mock...
I normally use #MockBean directly inside my test classes and inject the dedicated (but mocked) repository directly there and not create it inside the test configuration. I also add the test configuration class by #ContextConfiguration so it is loaded in current test context.
Inside my tests I am just using mockito the standard way and prepare the mocked parts as wanted for the dedicated test method.
Here an example snippet:
// ... do some imports ...
#RunWith(SpringRunner.class)
#ContextConfiguration(classes= {XYZSomeWantedClazz.class, DemoXYZMockTest.SimpleTestConfiguration.class})
#ActiveProfiles({Profiles.TEST})
public class DemoXYZMockTest {
//...
#MockBean
private DemoRepository mockedDemoRepository;
// ...
#Test
public void testMethodName() throws Exception{
/* prepare */
List<WantedEntityClazz> list = new ArrayList<>();
// add your wanted data to your list
// apply to mockito:
when(mockedDemoRepository.findAll()).thenReturn(list);
/* execute */
// ... execute the part you want to test...
/* test */
// ... test the results after execution ...
}
#TestConfiguration
#Profile(Profiles.TEST)
#EnableAutoConfiguration
public static class SimpleTestConfiguration{
// .. do stuff if necessary or just keep it empty
}
}
For a complete (old Junit4) working test example please take a look at:
https://github.com/mercedes-benz/sechub/blob/3f176a8f4c00b7e8577c9e3bea847ecfc91974c3/sechub-administration/src/test/java/com/daimler/sechub/domain/administration/signup/SignupAdministrationRestControllerMockTest.java

How to #Inject into main class - Java - Play Framework

I'm creating a main class in Play framework. Then I tried to #Inject another DAO object, as below:
public class HistoricalTask {
#Inject
protected static DataDao dataDao =
Play.current().injector().instanceOf(DataDao.class);
public static void main(String[] args) {
List<DataObject> rs = dataDao.getData();
}
}
But, it doesn't work. And I got an error:
Caused by: java.lang.RuntimeException: There is no started application
So, Is there any solution to create another main class, using #Inject feature and separate with Play web server?
Thank you, guys!
It is not possible to do that since your application is still in initialisation process.
If you want to initialise something at the time of application startup consider creating a module and add it to your application.conf file. Here you can register all the beans you want and any specific initialisation that you want to do by binding an eager singleton.
For example:
public class DaoHelperModule extends AbstractModule {
#Override
protected void configure() {
bind(DaoService.class).asEagerSingleton();
}
}
Then in application.conf file:
play.modules.enabled += "services.producer.DaoHelperModule"
You can inject dependencies in the module as well.

Not able to read value from properties file in Spring Boot using #Value annotation

I am not able to read a property from properties file through Spring Boot. I have a REST service which is working through the browser and Postman both and returning me a valid 200 response with data.
However, I am not able to read a property through this Spring Boot client using #Value annotation and getting following exception.
Exception:
helloWorldUrl = null
Exception in thread "main" java.lang.IllegalArgumentException: URI must not be null
at org.springframework.util.Assert.notNull(Assert.java:115)
at org.springframework.web.util.UriComponentsBuilder.fromUriString(UriComponentsBuilder.java:189)
at org.springframework.web.util.DefaultUriTemplateHandler.initUriComponentsBuilder(DefaultUriTemplateHandler.java:114)
at org.springframework.web.util.DefaultUriTemplateHandler.expandInternal(DefaultUriTemplateHandler.java:103)
at org.springframework.web.util.AbstractUriTemplateHandler.expand(AbstractUriTemplateHandler.java:106)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:612)
at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:287)
at com.example.HelloWorldClient.main(HelloWorldClient.java:19)
HelloWorldClient.java
public class HelloWorldClient {
#Value("${rest.uri}")
private static String helloWorldUrl;
public static void main(String[] args) {
System.out.println("helloWorldUrl = " + helloWorldUrl);
String message = new RestTemplate().getForObject(helloWorldUrl, String.class);
System.out.println("message = " + message);
}
}
application.properties
rest.uri=http://localhost:8080/hello
There are several problems in your code.
From the samples you posted, it seems that Spring is not even started. The main class should run the context in your main method.
#SpringBootApplication
public class HelloWorldApp {
public static void main(String[] args) {
SpringApplication.run(HelloWorldApp.class, args);
}
}
It isn't possible to inject a value into a static field. You should start with changing it into a regular class field.
The class must be managed by Spring container in order to make value injection available. If you use default component scan you can simply annotate the newly created client class with the #Component annotation.
#Component
public class HelloWorldClient {
// ...
}
If you don't want to annotate the class you can create a bean in one of your configuration classes or your main Spring Boot class.
#SpringBootApplication
public class HelloWorldApp {
// ...
#Bean
public HelloWorldClient helloWorldClient() {
return new HelloWorldClient();
}
}
However, if you are the owner of the class, the first option is preferable. No matter which way you choose, the goal is to make the Spring context aware of class existence so the injection process can happen.

Guice custom scope entry and exit in Java console application

I'm currently trying to implement injection in a Java console application using Guice. The application imports XML files in a database. Every import operation is done in an AbstractImporter, which can either be a UserImporter, a ScheduleImporter, etc.
public class ScheduleMigrator extends AbstractMigrator {
private final UserImporter userImporter;
private final ScheduleImporterFactory scheduleImporterFactory;
#Inject
public ScheduleMigrator(UserImporter userImporter,
ScheduleImporterFactory scheduleImporterFactory) {
this.userImporter = userImporter;
this.scheduleImporterFactory = scheduleImporterFactory;
}
public void migrate() {
// Migrate users
userImporter.run();
// Migrate schedules for each type
for (ScheduleType scheduleTypes : ScheduleType.values()) {
ScheduleImporter importer =
scheduleImporterFactory.create(scheduleTypes);
importer.run();
}
}
}
public class UserImporter extends AbstractImporter {
private final UserTransformer userTransformer;
private final ConfigurationService configurationService;
#Inject
public UserImporter(UserTransformer userTransformer,
ConfigurationService configurationService) {
this.userTransformer = userTransformer;
this.configurationService = configurationService;
}
public void run() {
// do stuff here
}
}
#Singleton
public class UserTransformer {
// ...code ommited...
}
#ImporterScoped
public class ConfigurationService {
// ...code ommited...
}
I have successfully created my own scope (#ImporterScoped) for classes that should only be available and instantiated only in an Importer. The scope was created by following the steps in the wiki. My problem is, how should I enter and exit the scope in ScheduleMigrator?
As you can see in ScheduleMigrator, each Importer is injected and its run() method is invoked. There are also factories (based on Guice's #AssistedInject feature). This is where I want each scope to start and end, UserImporter and ScheduleImporterFactory should run in their own scope.
This is a rough idea of what I'm trying to achieve:
importerScope.enter();
(new UserImporter()).run();
importerScope.exit();
Guice's documentation mentions the use of interceptors, but I'm a little lost on how it can be implemented.
Using AOP seems a very over-engineered approach and might introduce problems. When do I enter the scope? When do I exit? What happens if I instantiate two Importer objects?
Instead, I added a runScoped method in AbstractMigrator that takes a Runnable and executes it. Using injection I get the ImporterScope scope, enter and exit it appropriately.
protected void runScoped(Runnable function)
{
scenarioScope.enter();
try {
function.run();
}
finally {
scenarioScope.exit();
}
}
Usage:
runScoped(() -> {
ScheduleImporter importer =
scheduleImporterFactory.create(scheduleTypes);
importer.run();
});
This introduces one problem though. In ScheduleMigrator, I can't have Importers injected, because their instantiation would occur outside of a scope and Guice throws an OutOfScopeException. I had to wrap each Importer in a Provider.
private final Provider<UserImporter> userImporterProvider;
runScoped(() -> {
UserImporter importer = userImporterProvider.get();
importer.run();
});

Dependency Injection in simple java program using CDI

Do we always require a beans.xml for a dependency injection in a simple java program using only CDI,and do we need to construct a bean to get the objects injected???
Below are the codes for simple java project with dependency Injection::
Interface
public interface Hello
{
public void sayHello(String str);
}
class
public class HelloImpl1 implements Hello{
public void sayHello(String str){
System.out.println("Hello from 1st block")
}
}
class
public class HelloImpl2 implements hello{
public void sayHello(String str){
System.out.println("Hello from 2nd block")
}
}
Class
public CallingHello(){
#Inject
Hello hello;
public void callHello(){
hello.sayHello("Hey");
}
}
Class
public Test(){
public static void main(String[] args){
CallingHello hello=new CallingHello();
hello.callHello();
}
Thats all i am doing and while running the test class its throwing nullpointerexception,and i am making simple classes no bean in eclipse,m i going right??
You can use autowiring , in order to inject dependencies (and possibly apply post processors) to an object that is not part of the application context.
You can use java config class with factory methods to configure ApplicationContext:
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
#Configuration
public class AppConfig {
#Bean(name="HelloImpl1")
public HelloImpl1 helloImpl1() {
return new HelloImpl1();
}
#Bean(name="HelloImpl2")
public HelloImpl1 helloImpl2() {
return new HelloImpl2();
}
}
And then to instantiate:
ApplicationContext ctx =
new AnnotationConfigApplicationContext(AppConfig.class);
HelloImpl1 helloImpl1= (HelloImpl1)ctx.getBean("HelloImpl1");
helloImpl1.sayHello("#?*")
If you are using Spring for the dependency injection, you always need a configuration file. But it does not need to be named beans.xml.
Yes the beans are injected in other beans.
Technically no you don't have use an XML file define your beans and inject dependencies. It depends on the type of ApplicationContext you use. But, for most practical applications you'll use one of the AbstractXMLContextApplication instances which will load an XML file to figure out the beans your app has declared. The name of that file doesn't have to be beans.xml. That's a convention used, but it you don't have to name it that. You can override which file it looks for when you constructor the implementation of AbstractXMLApplicationContext object.
All you need to do is construct the bean container, and it will load the beans, resolve the dependencies, and startup the program (if you are using init-method). Typically my Spring Container Java programs look like this:
ApplicationContext context = null;
try {
context = new FileSystemXmlApplicationContext( new String[] { file } );
// pause until we want to shutdown or after something happens.
System.in.readLine();
} finally {
context.close(); // remember to clean up!
}
And I let the init methods on the bean startup my application.

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