In -depth research on the technical principles of the core framework in the Java class library

In -depth research on the technical principles of the core framework in the Java class library In the Java library, verification technology is a very important core framework technology to ensure the consistency and correctness of the data.This article will deepen the principles of verifying the core framework technology in the Java library, and provide some Java code examples to help readers better understand. Verification technology plays a key role in software development.In applications, data usually needs to meet certain constraints to ensure the correctness and security of the system.For example, a bank application needs to ensure that the deposit amount is greater than zero, and an e -commerce website needs to ensure that the mailbox address format of the user entered is correct.To meet these constraints, the Java class library provides a strong set of verification framework. The verification framework in the Java class library uses many different technologies to implement.The most commonly used technology is annotation and reflection.By adding annotations to the attributes of the Java class, developers can specify the verification rules of the attribute.The verification framework uses reflection to read these annotations and verify the attributes.The following is a simple example. It demonstrates how to use the verification framework in the Java class library to verify whether the age of a user is within the valid range: public class User { @Min (Value = 18, Message = "Age cannot be less than 18 years") @Max (Value = 60, Message = "Age cannot be greater than 60 years") private int age; // omit other attributes and methods } public class Main { public static void main(String[] args) { User user = new User(); user.setage (17); // Set a invalid age value ValidatorFactory factory = Validation.buildDefaultValidatorFactory(); Validator validator = factory.getValidator(); Set<ConstraintViolation<User>> violations = validator.validate(user); for (ConstraintViolation<User> violation : violations) { System.out.println(violation.getMessage()); } } } In the example above, the authentication rules of the `Age` attributes are added to the example of the examples above.Then verify the `User` object of the` value of the `validator` class.If the age is less than 18 or greater than 60, a verification error will be generated. You can obtain the error message by iteration. In addition to annotations and reflection, the verification framework in the Java class library also uses other technologies to implement.For example, use regular expressions to verify the string format, use custom verifications to achieve special verification logic, use internationalization to provide multi -language support, etc.The combination of these technologies makes the verification framework in the Java library has strong flexibility and scalability. In short, the verification core framework technology in the Java library is a very important technology to ensure the consistency and correctness of the data.By using annotations, reflexes, and other technologies, developers can easily implement data verification functions and improve the reliability and security of applications.