Use the Valdr Bean Validation framework to verify the data of the Java class library
Use the Valdr Bean Validation framework to verify the data of the Java class library
Overview:
Data verification is an indispensable link in the development process, especially in the scenario involved in user input.Valdr Bean Validation framework is a powerful tool for data verification in the Java library.This article will introduce how to use the Valdr Bean Validation framework to verify the Java library and provide a complete programming code and related configuration description.
1. Valdr Bean Validation framework:
Valdr Bean Validation is a implementation based on the Bean Validation specification.It defines data verification rules by annotations and provides simple and easy -to -use APIs for verification operations.Valdr Bean Validation framework supports common data verification scenarios, such as verifying compulsory fields, verification maximum lengths, verification mailbox formats, etc.
2. Installation and configuration of Valdr Bean Validation framework:
First of all, we need to add the relevant dependencies of the Valdr Bean Validation framework to the project dependency management.You can add the following dependencies in Maven or Gradle:
Maven dependency configuration:
<dependency>
<groupId>com.github.valdr</groupId>
<artifactId>valdr</artifactId>
<version>2.0.1</version>
</dependency>
Gradle dependency configuration:
groovy
implementation 'com.github.valdr:valdr:2.0.1'
3. Create verification rules:
Before creating the BEAN class library, let's define the verification rules.You can use annotations provided by the Valdr Bean Validation framework to define rules.For example, we define a User class, where the username field must be filled and the maximum length is 10. The email field must conform to the mailbox format:
public class User {
@Notnull (Message = "Username cannot be empty")
@Size (max = 10, message = "The maximum length of the user name is 10"))
private String username;
@Notnull (Message = "Email address cannot be empty")
@Email (Message = "Please enter valid mailbox address")
private String email;
// omit the definition of other fields and related getter and setter methods
}
4. Data verification:
Next, we need to use the API of the Valdr Bean Validation framework for data verification.The following is a simple example code:
import com.github.valdr.Valdr;
public class DataValidator {
public static void main(String[] args) {
User user = new User();
user.setUsername("John");
user.setEmail("john@example");
Valdr valdr = new Valdr();
ValidationResult validationResult = valdr.validate(user);
if (validationResult.isValid()) {
System.out.println ("Data Verification Pass");
} else {
validationResult.getViolations().forEach(violation -> {
System.out.println ("field:" + violation.getField ());
System.out.println ("Message:" + Violation.getMessage ());
});
}
}
}
In the above code, we created a User instance and set the values of username and email properties.We then verify the user instance using the validate () method of the Valdr Bean Validation framework.If the data verification passes, we output the message passed by the verification; otherwise, we traversed all the fields that failed to verify and output the field name and error message.
Summarize:
By using the Valdr Bean Validation framework, we can easily verify the Java library.This article introduces the installation and configuration of the Valdr Bean Validation framework, creates verification rules and the complete process of data verification, and provides related programming example code.I hope this article will help you in the data verification of the Java library.
