The error message that processs the JSR 303 verification constraints in the Java library
Processing the error information of the JSR 303 verification constraint framework
Introduction:
JSR 303 is a framework used in Java to verify and constraints. It allows developers to define verification rules in the physical class and verify these rules during runtime.This article will discuss the error information of how to process the JSR 303 verification constraint framework in order to better process and display error information.We will provide Java -based code examples to demonstrate each step in detail.
Step 1: Introduce dependencies
First, we need to introduce appropriate dependencies in the pom.xml file of the project.The following is an example Maven dependencies, including JSR 303 verification constraints and its implementation:
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>2.0.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.0.17.Final</version>
</dependency>
Step 2: Define the verification rules
In the physical class, we can use the JSR 303 annotation to define the verification rules.For example, suppose we have a physical class called User, where we need to verify the length of the user name and password:
public class User {
@Size (min = 6, max = 20, message = "User name length must be between 6 and 20 characters")
private String username;
@Size (min = 8, max = 15, message = "Password length must be between 8 and 15 characters")
private String password;
// omit other attributes and methods
}
Step 3: Execution verification
To perform verification, we need to use the JSR 303 verification device.The following is a verification method of an example, which will verify the verification rules of the USER instance:
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;
public class UserValidator {
private Validator validator;
public UserValidator() {
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
validator = factory.getValidator();
}
public void validateUser(User user) {
Set<ConstraintViolation<User>> violations = validator.validate(user);
if (!violations.isEmpty()) {
for (ConstraintViolation<User> violation : violations) {
System.out.println(violation.getMessage());
}
} else {
System.out.println ("Verification Pass");
}
}
}
Step 4: process error information
In the above examples, we have trapped the verification error information by traversing the Constraintvilation object collection.You can record the error information on the log file, display it on the user interface, or take other operations.The following is a modified example:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class UserValidator {
private Validator validator;
private Logger logger = LoggerFactory.getLogger(UserValidator.class);
public UserValidator() {
ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
validator = factory.getValidator();
}
public void validateUser(User user) {
Set<ConstraintViolation<User>> violations = validator.validate(user);
if (!violations.isEmpty()) {
for (ConstraintViolation<User> violation : violations) {
logger.error(violation.getMessage());
}
} else {
logger.info ("Verification Pass");
}
}
}
In this example, we use the SLF4J log frame to record error information.
in conclusion:
By following the above steps, we can process the error information of the JSR 303 verification constraint framework.We can process these error information according to actual needs to improve the user experience and reliability of the application.
I hope this article will be helpful for you when dealing with the error information of the JSR 303 verification constraint framework!
