Best Practices for Applying Bean Validation Scala in Java Class Libraries

The best practice of Bean Validation is in the Java class library Bean verification is a specification for verifying the Java object, which is mainly used to perform verification on the field of the object.This article will introduce the best practice to apply BEAN verification in the Java library and provide relevant Java code examples. 1. Introduce Bean verification dependencies To apply BEAN verification in the Java class library, we first need to introduce Bean verification related libraries in the dependence of the project.In Maven, you can add the following dependencies to pom.xml: <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>2.0.1.Final</version> </dependency> 2. Create the Java class that needs to be verified Create a Java class and add annotations for verification on the field of the class.For example, assuming that there is a User class, which contains an integer segment called "Age", we can add @min and @max annotations to the Age field to limit the value range of the Age field: public class User { @Min (Value = 18, Message = "Age must be greater than or equal to 18 years")) @Max (Value = 60, Message = "Age cannot exceed 60 years") private int age; // Other fields and methods are omitted ... } 3. Create a verification device class Create a verification device class to perform verification logic.The verification device class can be a single case or created by dependency injection.Here we create a verification device class called Validator, which contains a value method: import javax.validation.*; import java.util.*; public class Validator { private static ValidatorFactory validatorFactory = Validation.buildDefaultValidatorFactory(); public static <T> List<String> validate(T object) { List<String> errors = new ArrayList<>(); Validator validator = validatorFactory.getValidator(); Set<ConstraintViolation<T>> violations = validator.validate(object); for (ConstraintViolation<T> violation : violations) { errors.add(violation.getMessage()); } return errors; } } 4. Use the verification device in the class library Now we can use the Validator class to verify other parts of the library.For example, suppose we have an UserService class, which is a CreateUser method to create user objects.In the CreateUser method, we can use the Validator class to verify the legality of the user object: public class UserService { public User createUser(String name, int age) { User user = new User(); user.setName(name); user.setAge(age); List<String> validationErrors = Validator.validate(user); if (!validationErrors.isEmpty()) { Throw New iLleGALARGUMENTEXCEPTION } // Legal user objects, perform other logic ... return user; } } The above is the best practice to apply BEAN verification in the Java library. Summarize: Applying Bean to the Java library can effectively improve the quality and reliability of the code.By adding verification annotations to the object field, and using the verification device class to execute the verification logic, you can easily verify the legality of the object and find errors in time.At the same time, the use of error messages and abnormal processing can provide useful error prompts to facilitate the use of developers in this type of library for problems to investigate and debug problems. Note: Bean verification can only be verified during runtime, so it still needs to follow other conventional defensive programming measures, such as air value inspection and boundary verification.