Testing SpringBoot with Mockito.mock() vs @Mock vs @MockBean

How to test with SpringBoot

There are several ways to test a Spring Boot application, including unit tests, integration tests, and end-to-end tests.

Unit tests can be written using JUnit and test individual components of the application, such as service or repository classes. Spring Boot provides the @SpringBootTest annotation to enable loading of the application context for these tests.

Integration tests can be written using JUnit and the Spring Test and Spring Boot Test libraries. These tests run against the entire application and can test the interaction between multiple components. The @SpringBootTest annotation can also be used for integration tests.

End-to-end tests can be written using libraries such as Selenium or Cucumber and test the application from the perspective of an end user. These tests typically run against a deployed application and test the UI and user interactions.

You can also use mockMvc to test your controllers.
It is a powerful way to easily test Spring MVC controllers without starting a full HTTP server.

In summary, you can use JUnit and the Spring Test and Spring Boot Test libraries to write unit and integration tests, and use libraries such as Selenium or Cucumber for end-to-end tests. You can also use mockMvc to test your controllers.

Mockito.mock() example code

Here is an example of how to use Mockito to create a mock object:

import org.mockito.Mockito;

public class ExampleTest {
    @Test
    public void testExample() {
        // Create a mock object of the class you want to test
        MyService myService = Mockito.mock(MyService.class);

        // Set up the mock object's behavior
        Mockito.when(myService.doSomething()).thenReturn("Mocked result");

        // Use the mock object in your test
        Example example = new Example(myService);
        String result = example.useMyService();
        assertEquals("Mocked result", result);
    }
}

In this example, we are creating a mock object of the MyService class using the Mockito.mock() method. We are then using the when() method to specify the behavior of the mock object when the doSomething() method is called. In this case, we are telling the mock to return the string “Mocked result” when doSomething() is called.

In the test method, we are creating an instance of the class Example and passing it the mock object of MyService, then we are calling the useMyService() method of Example class and assert the result with the mocked result.

Mocking allows you to isolate the component you are testing, so that you can test its behavior independently of other components.

Please note that this is just an example and the actual implementation of the classes and methods used in this example might be different based on your use case.

@Mock example code

Here is an example of how to use the @Mock annotation to create a mock object:

import org.junit.jupiter.api.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)
public class ExampleTest {

    @Mock
    private MyService myService;

    @InjectMocks
    private Example example;

    @Test
    public void testExample() {
        // Set up the mock object's behavior
        Mockito.when(myService.doSomething()).thenReturn("Mocked result");

        // Use the mock object in your test
        String result = example.useMyService();
        assertEquals("Mocked result", result);
    }
}

In this example, we are using the @Mock annotation to create a mock object of the MyService class. We are then using the when() method to specify the behavior of the mock object when the doSomething() method is called. In this case, we are telling the mock to return the string “Mocked result” when doSomething() is called.

We also use the @InjectMocks annotation to inject the mock objects in the class we want to test Example.

In the test method, we are calling the useMyService() method of Example class and assert the result with the mocked result.

The @ExtendWith(MockitoExtension.class) is used to enable the usage of annotations in junit5.

Mocking allows you to isolate the component you are testing, so that you can test its behavior independently of other components.

@MockBean example code

Here is an example of how to use the @MockBean annotation to create a mock object in a Spring Boot application:

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit.jupiter.SpringExtension;

@ExtendWith(SpringExtension.class)
@SpringBootTest
public class ExampleTest {

    @MockBean
    private MyService myService;

    @Autowired
    private Example example;

    @Test
    public void testExample() {
        // Set up the mock object's behavior
        Mockito.when(myService.doSomething()).thenReturn("Mocked result");

        // Use the mock object in your test
        String result = example.useMyService();
        assertEquals("Mocked result", result);
    }
}

In this example, we are using the @MockBean annotation to create a mock object of the MyService class in a Spring Boot application. The @MockBean annotation can only be used in the context of a Spring Boot test and is used to replace a bean in the ApplicationContext with a mock.

We also use the @Autowired annotation to inject the Example class in the test case.

In the test method, we are calling the useMyService() method of Example class and assert the result with the mocked result.

The @ExtendWith(SpringExtension.class) and @SpringBootTest is used to enable the usage of annotations in junit5 and to load the spring context.

Mocking allows you to isolate the component you are testing, so that you can test its behavior independently of other components.

Testing with Mock for SpringBoot RestAPI Controller

Here is an example of how to use mock objects to test a Spring Boot REST API controller:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

import static org.mockito.Mockito.when;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@ExtendWith(MockitoExtension.class)
public class ExampleControllerTest {

    @Mock
    private MyService myService;

    @InjectMocks
    private ExampleController exampleController;

    private MockMvc mockMvc;

    @BeforeEach
    public void setUp() {
        mockMvc = MockMvcBuilders.standaloneSetup(exampleController).build();
    }

    @Test
    public void testGetData() throws Exception {
        // Set up the mock object's behavior
        when(myService.getData()).thenReturn("Mocked data");

        // Test the controller's GET endpoint
        mockMvc.perform(get("/data"))
                .andExpect(status().isOk())
                .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))
                .andExpect(content().string("Mocked data"));
    }
}

In this example, we are using the @Mock annotation to create a mock object of the MyService class, and the @InjectMocks annotation to inject the mock object into the ExampleController class.

We are also using the MockMvc class from the Spring Test framework to test the controller’s GET endpoint. MockMvcBuilders.standaloneSetup(controller) is used to set up a MockMvc instance to test the ExampleController.

In the test method, we are setting up the behavior of the mock object using when(myService.getData()).thenReturn(“Mocked data”); and then we are testing the /data endpoint by performing a GET request to the endpoint and asserting that the status code is 200 OK and the content type and body of the response are as expected.

This way you can test your RestAPI Controllers without starting a full HTTP server and without depending on any external resources.
Please note that this is just an example and the actual implementation of the classes and methods used in this example might be different based on your use case.

Testing Service Layer with SpringBoot and Mock

Here is an example of how to use mock objects to test a service layer in a Spring Boot application:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.Mockito.when;

@ExtendWith(MockitoExtension.class)
public class MyServiceTest {

    @Mock
    private MyRepository myRepository;

    @InjectMocks
    private MyService myService;

    @Test
    public void testGetData() {
        when(myRepository.findData()).thenReturn("Mocked data");
        String result = myService.getData();
        assertEquals("Mocked data", result);
    }
}

In this example, we are using the @Mock annotation to create a mock object of the MyRepository class, and the @InjectMocks annotation to inject the mock object into the MyService class.

In the test method, we are setting up the behavior of the mock object using when(myRepository.findData()).thenReturn(“Mocked data”); and then we are testing the getData() method of the MyService class by calling it and asserting that the result is equal to “Mocked data”.

This way you can test your Service Layer without starting a full HTTP server and without depending on any external resources.

Testing Repository Layer with SpringBoot and Mock

Here is an example of how to use mock objects to test a repository layer in a Spring Boot application:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.Mockito.when;

@ExtendWith(MockitoExtension.class)
public class MyRepositoryTest {
    @Mock
    private JdbcTemplate jdbcTemplate;

    @InjectMocks
    private MyRepository myRepository;

    @Test
    public void testFindData() {
        when(jdbcTemplate.query(anyString(), any(RowMapper.class))).thenReturn(List.of("Mocked data"));
        List result = myRepository.findData();
        assertEquals(List.of("Mocked data"), result);
    }
}

In this example, we are using the @Mock annotation to create a mock object of the JdbcTemplate class, and the @InjectMocks annotation to inject the mock object into the MyRepository class.

In the test method, we are setting up the behavior of the mock object using when(jdbcTemplate.query(anyString(), any(RowMapper.class))).thenReturn(List.of(“Mocked data”)); and then we are testing the findData() method of the MyRepository class by calling it and asserting that the result is equal to a list containing one element “Mocked data”.

Mocking Exception Throwing with Non-Void return

Here is an example of how to use mock objects to test a service layer that throws an exception:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.mockito.Mockito.when;

@ExtendWith(MockitoExtension.class)
public class MyServiceTest {

    @Mock
    private MyRepository myRepository;

    @InjectMocks
    private MyService myService;

    @Test
    public void testGetData() {
        when(myRepository.findData()).thenThrow(new IllegalArgumentException("Mocked exception"));
        assertThrows(IllegalArgumentException.class, () -> myService.getData());
    }
}

In this example, we are using the @Mock annotation to create a mock object of the MyRepository class, and the @InjectMocks annotation to inject the mock object into the MyService class.

In the test method, we are setting up the behavior of the mock object using when(myRepository.findData()).thenThrow(new IllegalArgumentException(“Mocked exception”)); and then we are testing the getData() method of the MyService class by calling it inside an assertThrows block and asserting that it throws an IllegalArgumentException with the message “Mocked exception”.

This way you can test your service layer and the exception handling of it.

Mocking Exception Throwing with Void return

Here is an example of how to use mock objects to test a service layer that throws an exception when a void method is called:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.mockito.Mockito.doThrow;

@ExtendWith(MockitoExtension.class)
public class MyServiceTest {

    @Mock
    private MyRepository myRepository;

    @InjectMocks
    private MyService myService;

    @Test
    public void testDeleteData() {
        doThrow(new IllegalArgumentException("Mocked exception")).when(myRepository).deleteData();
        assertThrows(IllegalArgumentException.class, () -> myService.deleteData());
    }
}

In this example, we are using the @Mock annotation to create a mock object of the MyRepository class, and the @InjectMocks annotation to inject the mock object into the MyService class.

In the test method, we are setting up the behavior of the mock object using doThrow(new IllegalArgumentException(“Mocked exception”)).when(myRepository).deleteData(); and then we are testing the deleteData() method of the MyService class by calling it inside an assertThrows block and asserting that it throws an IllegalArgumentException with the message “Mocked exception”.

Spy to throw an exception example code

Here is an example of how to use a spy object to test a service layer that throws an exception when a void method is called:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Spy;
import org.mockito.junit.jupiter.MockitoExtension;

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.mockito.Mockito.doThrow;

@ExtendWith(MockitoExtension.class)
public class MyServiceTest {

    @Spy
    private MyRepository myRepository;

    @InjectMocks
    private MyService myService;

    @Test
    public void testDeleteData() {
        doThrow(new IllegalArgumentException("Mocked exception")).when(myRepository).deleteData();
        assertThrows(IllegalArgumentException.class, () -> myService.deleteData());
    }
}

In this example, we are using the @Spy annotation to create a spy object of the MyRepository class, and the @InjectMocks annotation to inject the spy object into the MyService class.

AssertJ Exception Assertions example code

Here is an example of how to use AssertJ to assert that a specific exception is thrown in a test case:

import org.junit.jupiter.api.Test;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

public class MyServiceTest {

    @Test
    public void testDeleteData() {
        MyService myService = new MyService();
        assertThatThrownBy(() -> myService.deleteData())
                .isInstanceOf(IllegalArgumentException.class)
                .hasMessage("Invalid argument");
    }
}

In this example, we are using the assertThatThrownBy method from AssertJ to assert that the deleteData() method of the MyService class throws an IllegalArgumentException with the message “Invalid argument”.

We are wrapping the method call inside the assertThatThrownBy block, this way AssertJ will check if any exception was thrown, and if so it will check the type and message of the exception.

This way you can use a more expressive and readable way to assert the exceptions thrown by your code.

How to Set Up Swagger 2 with a Spring REST API Using Springfox example

What is Swagger 2?

Swagger 2 is a specification for building APIs. It is used to describe the functionality of an API and to generate documentation for it, making it easier for developers to understand and use the API. It is based on the OpenAPI Specification and is typically used in conjunction with the Swagger UI, a tool that can automatically generate interactive documentation for an API based on its Swagger definition.

What is Springfox

Springfox is a library for the Spring Framework that is used to automatically generate documentation for Spring-based APIs using the Swagger 2 specification. It allows developers to easily document their Spring controllers and models, and automatically generates a Swagger UI that can be used to test and interact with the API. Springfox provides a set of annotations and plugins that can be used to customize the generated documentation, such as adding descriptions and examples for parameters and responses.

Setting Up Swagger 2 with a Spring REST API Using Springfox

To set up Swagger 2 with a Spring REST API using Springfox, you will need to perform the following steps:

1. Add the Springfox dependencies to your project. This can typically be done by adding the following lines to your build file (e.g., pom.xml for Maven or build.gradle for Gradle):


    io.springfox
    springfox-swagger2
    2.9.2


    io.springfox
    springfox-swagger-ui
    2.9.2


2. Create a configuration class that enables Swagger by using the @EnableSwagger2 annotation. This class should also configure the Docket bean, which is used to configure the details of the generated documentation.

@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

3. Add the swagger-ui endpoint to your application by adding this line to your configuration class

@Bean
    public UiConfiguration uiConfig() {
        return UiConfigurationBuilder.builder()
                .deepLinking(true)
                .displayOperationId(false)
                .defaultModelsExpandDepth(1)
                .defaultModelExpandDepth(1)
                .defaultModelRendering(ModelRendering.EXAMPLE)
                .displayRequestDuration(false)
                .docExpansion(DocExpansion.NONE)
                .filter(false)
                .maxDisplayedTags(null)
                .operationsSorter(OperationsSorter.ALPHA)
                .showExtensions(false)
                .tagsSorter(TagsSorter.ALPHA)
                .supportedSubmitMethods(UiConfiguration.Constants.DEFAULT_SUBMIT_METHODS)
                .validatorUrl(null)
                .build();
    }

4. Run your application, and navigate to the http://localhost:8080/swagger-ui.html endpoint to see the generated documentation.

Note: You may need to adjust the package and class names, and the URL of the Swagger endpoint, to match your specific application.

Configuration Swagger 2 Without Spring Boot code example

Here is an example of how you might configure Swagger 2 without Spring Boot:

import io.swagger.jaxrs.config.BeanConfig;
import io.swagger.jaxrs.listing.ApiListingResource;
import io.swagger.jaxrs.listing.SwaggerSerializers;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
import java.util.HashSet;
import java.util.Set;

@ApplicationPath("/")
public class SwaggerConfig extends Application {
    public SwaggerConfig() {
        BeanConfig beanConfig = new BeanConfig();
        beanConfig.setTitle("My API");
        beanConfig.setVersion("1.0");
        beanConfig.setSchemes(new String[]{"http"});
        beanConfig.setHost("localhost:8080");
        beanConfig.setBasePath("/");
        beanConfig.setResourcePackage("com.myapi.controller");
        beanConfig.setPrettyPrint(true);
        beanConfig.setScan(true);
    }
    @Override
    public Set> getClasses() {
        Set> resources = new HashSet<>();
        resources.add(ApiListingResource.class);
        resources.add(SwaggerSerializers.class);
        resources.add(MyController.class);
        return resources;
    }
}

This example shows a configuration class called SwaggerConfig that extends javax.ws.rs.core.Application. In the constructor of the class, we create a BeanConfig object and set various properties, such as the title, version, and resource package of the API. The BeanConfig.setScan(true) will scan the package for the controllers and models.

In the getClasses() method, we add the ApiListingResource, SwaggerSerializers and the MyController class to the set of resources.

Finally, in your MyController class you can add the swagger annotations to the endpoint methods and classes,

@Api(value = "mycontroller", description = "My controller endpoints")
@Path("/mycontroller")
public class MyController {
    @GET
    @Path("/hello")
    @ApiOperation(value = "Say Hello", response = String.class)
    public String sayHello() {
        return "Hello";
    }
}

When you deploy your application, you can access the Swagger UI by navigating to http://localhost:8080/swagger.json in your browser, and you can test and interact with the API using the Swagger UI.

It’s important to note that this is just an example, and you might need to make changes based on the requirements of your specific project.

Spring Data REST with Swagger 2

Spring Data REST is a library for creating RESTful web services that are built on top of the Spring Data repositories. It allows you to easily expose your data entities as RESTful resources without having to manually write controllers for each entity.

To configure Spring Data REST with Swagger 2, you will need to include the following steps:

1. Add the necessary dependencies to your project, including the spring-data-rest-hal-browser and springfox-swagger2 libraries.

2. In your configuration class, you will need to configure the Swagger Bean and scan the packages for the Spring Data REST repositories.

3. Create a Docket bean, which is the primary interface for configuring the Swagger documentation. This is where you can set the title, version, and other information for the API.

4. Use the Docket bean to configure the Swagger UI by specifying the path, title, and version of the API.

5. In your Spring Data REST repositories, you need to add the @RepositoryRestResource annotation on the repositories and you can add the swagger annotations to the repositories and classes

6. You can then deploy your application and access the Swagger UI by navigating to the specified path in your browser.

Here is an example of how you might configure Spring Data REST with Swagger 2:

@Configuration
@EnableSwagger2
public class SwaggerConfig {

    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build()
                .apiInfo(apiInfo());
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("My API")
                .description("My API Description")
                .version("1.0")
                .build();
    }
}

@RepositoryRestResource(path = "users", collectionResourceRel = "users")
@Api(value = "users", description = "Users Endpoints")
public interface UserRepository extends PagingAndSortingRepository {
    @RestResource(path = "by-email")
    @ApiOperation(value = "Find user by email", response = User.class)
    User findByEmail(@Param("email") String email);
}

You can then deploy your application and access the Swagger UI by navigating to http://localhost:8080/swagger-ui.html in your browser, and you can test and interact with the API using the Swagger UI.

Note that Spring Data REST provides a lot of functionality out of the box, so you might not need to add extra code to expose your entities as RESTful resources.

Spring Bean Validations with Swagger 2

Spring Bean Validation is a way to validate the input of your API endpoints by defining constraints on the properties of your model objects. These constraints are defined using annotations, such as @NotNull or @Size, which can be applied to fields, methods, or constructors.

To configure Spring Bean Validation with Swagger 2, you will need to include the following steps:

1. Add the necessary dependencies to your project, including the spring-boot-starter-validation and springfox-swagger2 libraries.

2. In your configuration class, you will need to configure the validation bean.

3. Create a Docket bean, which is the primary interface for configuring the Swagger documentation. This is where you can set the title, version, and other information for the API.

4. Use the Docket bean to configure the Swagger UI by specifying the path, title, and version of the API.

5. In your endpoint methods, you need to add the @Valid annotation on the request object

6. You can then deploy your application and access the Swagger UI by navigating to the specified path in your browser.

Here is an example of how you might configure Spring Bean Validation with Swagger 2:

@Configuration
public class ValidationConfig {
    @Bean
    public LocalValidatorFactoryBean validator() {
        return new LocalValidatorFactoryBean();
    }
}

@Api(value = "users", description = "Users Endpoints")
@RestController
@RequestMapping("/users")
public class UserController {
    @PostMapping
    public ResponseEntity createUser(@Valid @RequestBody User user) {
        // create user logic
    }
}

public class User {
    @NotNull
    @Size(min = 3, max = 20)
    private String name;

    @Email
    private String email;
    // getters and setters
}

You can then deploy your application and access the Swagger UI by navigating to http://localhost:8080/swagger-ui.html in your browser, and you can test and interact with the API using the Swagger UI.

When you use the swagger UI, it will take the validation annotations in your model and display them in the UI, like min and max length of a string, or the format of an email. This way, it’s easy for the developer to understand the validation constraints.

Swagger 2 Plugin SpringBoot

A Swagger 2 plugin for Spring Boot is a library that can be added to a Spring Boot project to automatically generate and serve the Swagger UI, which is a web-based interface for interacting with and testing an API. The Swagger UI allows developers to see the endpoints of the API, the request and response formats, and any constraints or validation rules.

One popular plugin for Spring Boot is Springfox, which is a library that integrates Swagger 2 with Spring Boot. It allows developers to easily document their Spring controllers and models, and automatically generates a Swagger UI that can be used to test and interact with the API.

To include the Springfox library in your Spring Boot project, you will need to add the following dependency to your build file:


    io.springfox
    springfox-swagger2
    3.0.0

You will also need to create a SwaggerConfig class that will configure the Docket bean and scan the packages for controllers and models.

@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build()
                .apiInfo(apiInfo());
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("My API")
                .description("My API Description")
                .version("1.0")
                .build();
    }
}

After that, you can access the Swagger UI by navigating to http://localhost:8080/swagger-ui.html in your browser.

It’s important to note that there are other libraries and plugins available for integrating Swagger 2 with Spring Boot, and the specific steps for adding them to your project may vary.

Swagger UI With an OAuth-Secured API

If your API is secured with OAuth, you will need to configure the Swagger UI to include the necessary OAuth information, such as the authorization URL, client ID, and client secret. This will allow developers to authenticate with the API and test the endpoints using the Swagger UI.

There are a few different ways to configure the Swagger UI for an OAuth-secured API, depending on the specific requirements of your project. Here are a couple of examples:

1. Using Springfox: If you are using Springfox for your Swagger configuration, you can use the securitySchemes and security properties of the Docket bean to configure the OAuth information. For example:

@Configuration
@EnableSwagger2
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build()
                .apiInfo(apiInfo())
                .securitySchemes(Arrays.asList(securityScheme()))
                .securityContexts(Arrays.asList(securityContext()));
    }

    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("My API")
                .description("My API Description")
                .version("1.0")
                .build();
    }

    private SecurityScheme securityScheme() {
        GrantType grantType = new ImplicitGrant(new LoginEndpoint("http://localhost:8080/oauth/authorize"), "access_token");

        SecurityScheme oauth = new OAuthBuilder().name("spring_oauth")
                .grantTypes(Arrays.asList(grantType))
                .scopes(Arrays.asList(scopes()))
                .build();
        return oauth;
    }

    private SecurityContext securityContext() {
        return SecurityContext.builder()
                .securityReferences(Arrays.asList(new SecurityReference("spring_oauth", scopes())))
                .forPaths(PathSelectors.any())
                .build();
    }

    private AuthorizationScope[] scopes() {
        return new AuthorizationScope[]{
                new AuthorizationScope("read", "for read operations"),
                new AuthorizationScope("write", "for write operations")
        };
    }
}

2. Using the Swagger UI OAuth2 configuration page: You can use the Swagger UI OAuth2 configuration page to set the OAuth information directly in the browser. This approach allows you to use any OAuth 2.0 flow and any OAuth 2.0 provider, as long as the provider supports the OAuth 2.0 implicit flow.
In this case, you would need to enable the OAuth2 implicit flow in your provider and configure the swagger-ui with the appropriate client_id and redirect_url, then navigate to the OAuth2 configuration page in the Swagger UI and configure the OAuth information.

It’s important to note that these are just examples, and the specific steps for configuring the Swagger UI for an OAuth-secured API will depend on the requirements of your project and the OAuth provider you are using.

@lob annotation in spring boot

@lob annotation in spring boot

The @Lob annotation in Spring Boot is used to indicate that a field in an entity class should be persisted as a Large Object (LOB). A LOB is a large data type that can store a large amount of data, such as a BLOB (binary large object) or a CLOB (character large object).

Here’s an example of how you might use the @Lob annotation in a Spring Boot application:

import javax.persistence.Lob;

@Entity
public class Document {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  private String name;

  @Lob
  private byte[] content;

  // Getters and setters
}

In this example, the content field of the Document entity is annotated with @Lob, which indicates that it should be persisted as a BLOB in the database.

The @Lob annotation can be used with the following field types: byte[], Byte[], InputStream, Reader, and char[].

Create RestAPI with SpringBoot PostgreSQL and @lob

To create a REST API with Spring Boot, PostgreSQL, and the @Lob annotation, you will need to do the following:

1. Create a new Spring Boot project and add the PostgreSQL dependency to your pom.xml file.


  org.postgresql
  postgresql
  42.2.14


2. Configure the database connection in your application.properties file.

spring.datasource.url=jdbc:postgresql://localhost:5432/your-database-name
spring.datasource.username=your-username
spring.datasource.password=your-password

3. Create an entity class to represent the object you want to store in the database. Annotate fields that should be persisted as LOBs with the @Lob annotation.

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Lob;

@Entity
public class Document {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  private String name;

  @Lob
  private byte[] content;

  // Getters and setters
}

4. Create a repository interface to manage the persistence of your entity.

import org.springframework.data.jpa.repository.JpaRepository;

public interface DocumentRepository extends JpaRepository {
}

Spring Boot Upload Large file to S3 example code

Spring Boot Upload Large file to S3 example code

To upload a large file to Amazon S3 using Spring Boot, you will need to do the following:

First, create an S3 client using the AWS SDK for Java. You will need to provide your AWS access key and secret key in order to authenticate the client.

Next, create a TransferManager using the S3 client. The TransferManager class provides a high-level API for uploading and downloading files to and from S3.

Use the TransferManager to upload the file to S3. You can use the uploadFile method to upload the file as a single part, or the uploadMultipartFile method to upload it as multiple parts in parallel.

Optionally, you can also set a progress listener on the Upload object returned by the uploadFile or uploadMultipartFile method. This listener will be notified of the progress of the upload.

Here’s some sample code that demonstrates how to do this:

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.transfer.TransferManager;
import com.amazonaws.services.s3.transfer.Upload;

import java.io.File;

public class S3Uploader {
    public static void main(String[] args) throws Exception {
        // Replace these with your own access key and secret key
        String accessKey = "your-access-key";
        String secretKey = "your-secret-key";

        // Create an S3 client
        AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3Client s3Client = new AmazonS3Client(credentials);

        // Create a TransferManager
        TransferManager transferManager = new TransferManager(s3Client);

        // Upload a file to S3
        File file = new File("/path/to/large/file.zip");
        String bucketName = "your-bucket-name";
        String key = "file.zip";
        Upload upload = transferManager.upload(bucketName, key, file);

        // You can poll your transfer's status to check its progress
        while (upload.isDone() == false) {
            System.out.println("Transfer: " + upload.getDescription());
            System.out.println("  - State: " + upload.getState());
            System.out.println("  - Progress: " + upload.getProgress().getBytesTransferred());
            Thread.sleep(2000);
        }

        // Or you can block and wait for the upload to finish
        upload.waitForCompletion();

        // After the upload is complete, you can check your transfer's status
        System.out.println("Transfer: " + upload.getDescription());
        System.out.println("  - State: " + upload.getState());
        System.out.println("  - Progress: " + upload.getProgress().getBytesTransferred());
    }
}

AWS S3 split large file

One way to split a large file into multiple smaller files is to use the split command-line utility. You can use the split utility to split the file into equal-sized parts, or you can specify the size of the parts directly.

For example, to split a file called large_file.zip into 100MB parts, you can use the following command:

split -b 100m large_file.zip large_file.zip.part

This will create multiple files with names like large_file.zip.partaa, large_file.zip.partab, and so on. Each file will be approximately 100MB in size.

You can then upload each of these smaller files to S3 using the TransferManager class, as I described in my previous message. Once all of the parts have been uploaded, you can use the completeMultipartUpload method of the AmazonS3 class to combine the parts back into a single object in S3.

Here’s some sample code that demonstrates how to do this:

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.CompleteMultipartUploadRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadRequest;
import com.amazonaws.services.s3.model.InitiateMultipartUploadResult;
import com.amazonaws.services.s3.model.PartETag;
import com.amazonaws.services.s3.model.UploadPartRequest;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

public class S3MultipartUploader {
    public static void main(String[] args) throws Exception {
        // Replace these with your own access key and secret key
        String accessKey = "your-access-key";
        String secretKey = "your-secret-key";

        // Create an S3 client
        AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3Client s3Client = new AmazonS3Client(credentials);

        // Initialize the multipart upload
        String bucketName = "your-bucket-name";
        String key = "large_file.zip";
        InitiateMultipartUploadRequest initiateRequest = new InitiateMultipartUploadRequest(bucketName, key);
        InitiateMultipartUploadResult initiateResult = s3Client.initiateMultipartUpload(initiateRequest);
        String uploadId = initiateResult.getUploadId();

        // Upload the parts
        List partETags = new ArrayList<>();
        File file = new File("/path/to/large_file.zip");
        long contentLength = file.length();
        long partSize = 5 * 1024 * 1024; // Set part size to 5 MB
        long filePosition = 0;
        for (int i = 1; filePosition < contentLength; i++) {
            // Last part can be less than 5 MB
            partSize = Math.min(partSize, (contentLength - filePosition));
            // Create request to

Upload multiple files to S3 Spring Boot

To upload multiple files to Amazon S3 using Spring Boot, you can use the TransferManager class as I described in my previous message. The TransferManager class provides a high-level API for uploading and downloading files to and from S3.

Here's some sample code that demonstrates how to use the TransferManager to upload multiple files to S3:

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.transfer.TransferManager;

import java.io.File;

public class S3Uploader {
    public static void main(String[] args) throws Exception {
        // Replace these with your own access key and secret key
        String accessKey = "your-access-key";
        String secretKey = "your-secret-key";

        // Create an S3 client
        AWSCredentials credentials = new BasicAWSCredentials(accessKey, secretKey);
        AmazonS3Client s3Client = new AmazonS3Client(credentials);

        // Create a TransferManager
        TransferManager transferManager = new TransferManager(s3Client);

        // Upload multiple files to S3
        File file1 = new File("/path/to/file1.zip");
        String bucketName = "your-bucket-name";
        String key1 = "file1.zip";
        Upload upload1 = transferManager.upload(bucketName, key1, file1);

        File file2 = new File("/path/to/file2.zip");
        String key2 = "file2.zip";
        Upload upload2 = transferManager.upload(bucketName, key2, file2);

        // You can use a Transfer.Waiter to block until the upload completes
        upload1.waitForCompletion();
        upload2.waitForCompletion();

        // Or you can use a Transfer.TransferListener to track the progress of the upload
        upload1.addProgressListener(new UploadProgressListener());
        upload2.addProgressListener(new UploadProgressListener());
    }
}

class UploadProgressListener implements Transfer.ProgressListener {
    public void progressChanged(Transfer.ProgressEvent progressEvent) {
        // Your code here
    }
}

Spring Lambda upload large file to S3

To upload a large file to Amazon S3 from a Spring Boot application running on AWS Lambda, you can use the TransferManager class as I described in my previous messages. The TransferManager class provides a high-level API for uploading and downloading files to and from S3.

Here's some sample code that demonstrates how to use the TransferManager to upload a large file to S3 from a Spring Boot application running on AWS Lambda:

import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.services.lambda.AWSLambda;
import com.amazonaws.services.lambda.AWSLambdaClientBuilder;
import com.amazonaws.services.lambda.model.InvokeRequest;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.transfer.TransferManager;
import com.amazonaws.services.s3.transfer.Upload;

import java.io.File;
import java.nio.ByteBuffer;

@SpringBootApplication
public class S3UploaderLambdaApplication {
    public static void main(String[] args) throws Exception {
        // Create an S3 client
        AmazonS3 s3Client = AmazonS3ClientBuilder.standard()
                .withCredentials(new DefaultAWSCredentialsProviderChain())
                .withRegion(Regions.US_EAST_1)
                .build();

        // Create a TransferManager
        TransferManager transferManager = new TransferManager(s3Client);

        // Upload a file to S3
        File file = new File("/path/to/large/file.zip");
        String bucketName = "your-bucket-name";
        String key = "file.zip";
        Upload upload = transferManager.upload(bucketName, key, file);

        // You can use a Transfer.Waiter to block until the upload completes
        upload.waitForCompletion();

        // Or you can use a Transfer.TransferListener to track the progress of the upload
        upload.addProgressListener(new UploadProgressListener());
    }
}

class UploadProgressListener implements Transfer.ProgressListener {
    public void progressChanged(Transfer.ProgressEvent progressEvent) {
        // Your code here
    }
}

Note that in this example, I'm using the DefaultAWSCredentialsProviderChain to provide the AWS credentials for the S3 client. This will automatically look for credentials in the following order:

Environment variables (AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY)
Java system properties (aws.accessKeyId and aws.secretKey)
The default credentials profile in the ~/.aws/credentials file
The Amazon EC2 instance metadata service

Crud operation in React.js & RDS

Crud operation in React.js & RDS with Nodejs

To perform CRUD (create, read, update, delete) operations on an RDS database from a React.js application, you will need to use a server-side language to interact with the database. Here is an example of how you might implement CRUD operations using Node.js and the MySQL library:

1. Install the MySQL library: npm install mysql
2. Set up a connection to the RDS database in a Node.js server:

const mysql = require('mysql');

const connection = mysql.createConnection({
  host: 'your-rds-endpoint',
  user: 'your-username',
  password: 'your-password',
  database: 'your-database'
});

connection.connect();

3. Create a function to perform a CREATE operation:

function create(item) {
  return new Promise((resolve, reject) => {
    connection.query('INSERT INTO items SET ?', item, (error, results) => {
      if (error) {
        reject(error);
      } else {
        resolve(results.insertId);
      }
    });
  });
}

4. Create a function to perform a READ operation:

function read(id) {
  return new Promise((resolve, reject) => {
    connection.query('SELECT * FROM items WHERE id = ?', [id], (error, results) => {
      if (error) {
        reject(error);
      } else {
        resolve(results[0]);
      }
    });
  });
}

5. Create a function to perform an UPDATE operation:

function update(id, item) {
  return new Promise((resolve, reject) => {
    connection.query('UPDATE items SET ? WHERE id = ?', [item, id], (error, results) => {
      if (error) {
        reject(error);
      } else {
        resolve();
      }
    });
  });
}

6. Create a function to perform a DELETE operation:

function delete(id) {
  return new Promise((resolve, reject) => {
    connection.query('DELETE FROM items WHERE id = ?', [id], (error, results) => {
      if (error) {
        reject(error);
      } else {
        resolve();
      }
    });
  });
}

7. In your React.js application, use Axios or another HTTP library to make requests to the Node.js server and perform the CRUD operations:

import axios from 'axios';

// create an item
axios.post('/api/items', { name: 'item1' }).then(response => {
  console.log(response.data.id);
});

// read an item
axios.get('/api/items/1').then(response => {
  console.log(response.data);
});

// update an item
axios.put('/api/items/1', { name: 'item2' }).then(response => {
  console.log(response.data);
});

// delete an item
axios.delete('/api/items

Crud operation in React.js & RDS with SpringBoot

To perform CRUD (create, read, update, delete) operations on an RDS database from a React.js application using Spring Boot, you will need to create a Spring Boot API that communicates with the database. Here is an example of how you might implement CRUD operations using Spring Boot and the MySQL library:

1. Add the MySQL dependency to your build.gradle file:

dependencies {
  compile('org.springframework.boot:spring-boot-starter-data-jpa')
  compile('mysql:mysql-connector-java')
}

2. Set up a connection to the RDS database in your Spring Boot application:

spring.datasource.url=jdbc:mysql://your-rds-endpoint/your-database
spring.datasource.username=your-username
spring.datasource.password=your-password

3. Create a model class for your items:

@Entity
@Table(name = "items")
public class Item {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private long id;

  @Column(name = "name")
  private String name;

  // getters and setters
}

4. Create a repository interface to perform CRUD operations:

public interface ItemRepository extends CrudRepository {
}

5. Create a controller to handle HTTP requests and delegate to the repository:

@RestController
@RequestMapping("/api/items")
public class ItemController {

  private final ItemRepository repository;

  public ItemController(ItemRepository repository) {
    this.repository = repository;
  }

  @PostMapping
  public Item create(@RequestBody Item item) {
    return repository.save(item);
  }

  @GetMapping("/{id}")
  public Item read(@PathVariable long id) {
    return repository.findById(id).orElse(null);
  }

  @PutMapping("/{id}")
  public Item update(@PathVariable long id, @RequestBody Item item) {
    item.setId(id);
    return repository.save(item);
  }

  @DeleteMapping("/{id}")
  public void delete(@PathVariable long id) {
    repository.deleteById(id);
  }
}

6. In your React.js application, use Axios or another HTTP library to make requests to the Spring Boot API and perform the CRUD operations:

import axios from 'axios';

// create an item
axios.post('/api/items', { name: 'item1' }).then(response => {
  console.log(response.data.id);
});

// read an item
axios.get('/api/items/1').then(response => {
  console.log(response.data);
});

// update an item
axios.put('/api/items/1', { name: 'item2' }).then(response => {
  console.log(response.data);
});

// delete an item
axios.delete('/api

Crud operation in React.js & RDS with Python

To perform CRUD (create, read, update, delete) operations on an RDS database from a React.js application using Python, you will need to create a Python server that communicates with the database. Here is an example of how you might implement CRUD operations using the Flask and PyMySQL libraries:

1. Install the Flask and PyMySQL libraries: pip install flask pymysql
2. Set up a connection to the RDS database in your Python server:

import pymysql

connection = pymysql.connect(
    host='your-rds-endpoint',
    user='your-username',
    password='your-password',
    db='your-database',
    cursorclass=pymysql.cursors.DictCursor
)

3. Create a Flask route to handle a CREATE operation:

@app.route('/api/items', methods=['POST'])
def create():
    with connection.cursor() as cursor:
        cursor.execute('INSERT INTO items (name) VALUES (%s)', (request.form['name'],))
        item_id = cursor.lastrowid
    connection.commit()
    return str(item_id)

4. Create a Flask route to handle a READ operation:

@app.route('/api/items/', methods=['GET'])
def read(id):
    with connection.cursor() as cursor:
        cursor.execute('SELECT * FROM items WHERE id = %s', (id,))
        item = cursor.fetchone()
    return jsonify(item)

5. Create a Flask route to handle an UPDATE operation:

@app.route('/api/items/', methods=['PUT'])
def update(id):
    with connection.cursor() as cursor:
        cursor.execute('UPDATE items SET name = %s WHERE id = %s', (request.form['name'], id))
    connection.commit()
    return ''

6. Create a Flask route to handle a DELETE operation:

@app.route('/api/items/', methods=['DELETE'])
def delete(id):
    with connection.cursor() as cursor:
        cursor.execute('DELETE FROM items WHERE id = %s', (id,))
    connection.commit()
    return ''