When configuring Global Method Security, which attribute determines the order in which the security annotations are evaluated?
- prePostAnnotations
- order
- securedEnabled
- jsr250Enabled
The order attribute determines the order in which security annotations are evaluated. A lower order value means higher precedence. By setting the order attribute, you can control the order of evaluation for security annotations like @PreAuthorize and @PostAuthorize.
To create a simple unit test in Spring Boot, you can use the _____ annotation to load a minimal test context.
- @Autowired
- @RunWith
- @SpringBootTest
- @TestContext
In Spring Boot, the @SpringBootTest annotation is used to create a simple unit test and load a minimal test context. This allows you to test components of your application in isolation.
In Spring Boot, which annotation is primarily used to perform Bean Validation on fields?
- @Validated
- @CheckField
- @BeanValidation
- @Valid
In Spring Boot, the primary annotation used to perform Bean Validation on fields is @Valid. This annotation is typically used in conjunction with @RequestBody in controller methods to validate the request body and ensure that the incoming data adheres to the defined validation constraints for the associated class. The other options (@Validated, @CheckField, and @BeanValidation) are not the standard annotations used for this purpose in Spring Boot.
In Spring Security, how can method security expressions be utilized to implement complex security constraints on service methods?
- By adding custom filters to the Spring Security filter chain
- By configuring security rules in XML configuration files
- By embedding SpEL (Spring Expression Language) expressions within @PreAuthorize or @PostAuthorize annotations
- By using Java AOP (Aspect-Oriented Programming) for method-level security
In Spring Security, complex security constraints on service methods can be implemented by embedding SpEL expressions within the @PreAuthorize or @PostAuthorize annotations. This allows you to create dynamic and fine-grained security rules based on method parameters and other contextual information.
How can you handle scenarios where both @RequestBody and @ResponseBody are required in a controller method in Spring Boot?
- Use only @RequestParam to pass data between the client and server.
- Combine @RequestParam and @ResponseBody in the method signature.
- Utilize @ModelAttribute to encapsulate both input and output data.
- Annotate the method with @RestController and @ResponseBody.
When both @RequestBody and @ResponseBody are required in a Spring Boot controller method, you can use @ModelAttribute (Option 3) to encapsulate both input and output data. This allows you to handle both incoming data and outgoing responses in a single object. The other options don't effectively handle both input and output scenarios or may not follow best practices for handling requests and responses in a Spring Boot controller.
In Spring Boot, the _____ annotation is used to specify that a class is a candidate for component scanning.
- @ComponentScan
- @Configuration
- @Component
- @Autowired
In Spring Boot, the @Component annotation is used to specify that a class is a candidate for component scanning. This annotation marks a Java class as a bean so that the Spring container can recognize it and manage it. The other options, such as @ComponentScan, @Configuration, and @Autowired, have different purposes within the Spring framework.
How can you alter the Bean Lifecycle methods in Spring?
- By extending the BeanFactory class and overriding methods.
- By modifying the Spring configuration file (XML or JavaConfig).
- By creating a custom annotation and attaching it to a method.
- By using Aspect-Oriented Programming (AOP) and intercepting bean creation.
Bean Lifecycle methods in Spring can be altered by extending the BeanFactory class and overriding its methods. This allows you to customize the bean creation process. While other options may be used in Spring configuration or AOP, they do not directly alter the Bean Lifecycle methods themselves.
How can you configure multiple DataSources in a Spring Boot application?
- By defining multiple @DataSource beans in the application context.
- By annotating the main application class with @MultipleDataSources.
- By modifying the application.properties or application.yml file.
- Spring Boot does not support multiple DataSources.
To configure multiple DataSources in a Spring Boot application, you typically modify the application.properties or application.yml file to define the necessary DataSource properties. Spring Boot provides a convenient way to configure DataSources through properties, making it easy to connect to multiple databases. The other options are not standard practices for configuring multiple DataSources in a Spring Boot application.
In Spring Boot, how do you handle conflicts between properties defined in the application properties file and environment variables?
- Spring Boot automatically resolves conflicts without any specific configuration.
- The environment variables always override properties file values.
- The properties defined in the application properties file take precedence.
- You need to manually specify the resolution order using the PropertySourcesPlaceholderConfigurer.
In Spring Boot, conflicts between properties defined in the application properties file and environment variables are resolved by giving precedence to environment variables. This means that if a property is defined in both places, the environment variable value will override the value in the properties file. This behavior is designed to make it easier to configure applications in different environments using environment variables.
What is the role of backpressure in Reactive Streams, and how is it managed in Spring Boot?
- Backpressure controls the flow of data from the publisher to the subscriber.
- Backpressure is used to prevent data loss in case of slow consumers.
- Spring Boot doesn't support backpressure in Reactive Streams.
- Spring Boot uses thread blocking to handle backpressure.
Backpressure in Reactive Streams is a mechanism to deal with situations where a subscriber can't keep up with the rate of data emitted by the publisher. It allows the subscriber to signal the publisher to slow down or stop emitting data temporarily. Spring Boot handles backpressure by allowing subscribers to request a specific number of items they can handle, and the publisher will respect this request, preventing data loss or overwhelming the subscriber.