Technical principles in the Java class library: an introduction to the validation framework in Java Class Libraries)
Technical principles in the Java class library: Introduction to the verification framework
Overview:
In the Java library, the verification framework is an important technical principle that to ensure that the input data or object meets specific conditions and constraints.The verification framework provides a general method to verify the effectiveness of the data and detect possible errors.This framework can help developers write more stable and reliable code and reduce potential errors.
Advantages of verification framework:
The verification framework provides the following important advantages:
1. Improve the maintenance of code: By verifying the framework, the verification logic can be separated from the business code to improve the maintenance of the code.Verification rules can be concentrated in a definition, and can be reused in different places, reducing the redundant and maintenance costs of the code.
2. Improve the readability of code: By verifying the framework, the verification rules can be presented in a structured way to make it easier to understand and maintain.Developers can easily view the verification rules and understand the expected behavior of the code.
3. Improve the reliability of code: Verify the framework to ensure the effectiveness of the input data and prevent potential errors.This can reduce the abnormalities and errors of the program during running, and improve the reliability of the code.
4. Simplify the writing of code: The verification framework provides a set of ready -made verification rules and functions, which can simplify the process of writing verification logic for developers.Developers only need to choose appropriate verification rules to apply them to their data or objects.
Common Java verification framework:
Here are some commonly used Java verification frameworks:
1. Hibernate Validator: Hibernate Validator is a powerful Java verification framework based on the JSR 380 specification.It provides many built -in verification annotations, such as@notnull,@size,@email, etc.Through annotations, you can easily define the verification rules on the fields or methods of the Java class.
The following is an example code that uses Hibernate Validator for verification:
public class User {
@NotNull
private String username;
@Size(min = 8, max = 20)
private String password;
// Getters and setters
}
public class ValidatorExample {
public static void main(String[] args) {
User user = new User();
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
Set<ConstraintViolation<User>> violations = validator.validate(user);
for (ConstraintViolation<User> violation : violations) {
System.out.println(violation.getPropertyPath() + ": " + violation.getMessage());
}
}
}
2. Apache Commons Validator: Apache Commons Validator is another commonly used Java verification framework.It provides a set of verification functions that can be applied to different types of data.These functions can be used to check strings, numbers, dates, email addresses, etc.
The following is an example code that uses Apache Commons Validator for verification:
public class ValidatorExample {
public static void main(String[] args) {
String email = "test@example.com";
boolean isValidEmail = GenericValidator.isEmail(email);
if (isValidEmail) {
System.out.println("Email is valid.");
} else {
System.out.println("Email is invalid.");
}
}
}
Summarize:
The verification framework is an important technical principle in the Java class library, which provides a general method to verify the effectiveness of the input data.By using the verification framework, developers can improve the maintenance, readability and reliability of the code, and simplify the writing process of code.Hibernate Validator and Apache Commons Validator are commonly used Java verification frameworks that can meet different verification needs.Through reasonable use of the verification framework, developers can write more stable and reliable code.
