Understand the Valdr Bean Validation framework in Java Library

Title: Detailed Explanation of the use scene and related configuration of the Valdr Bean Validation framework in the Java Class Library Introduction: Valdr is an annotated BEAN verification framework, designed for Java libraries.This article will introduce the use scenario of the VALDR framework, and provide a complete programming code and related configuration to help readers in -depth understanding of Valdr's usage and usage scenarios. text: In Java development, Bean verification is a common method for verifying data.The Valdr framework makes Bean's verification more flexible and easy to manage.Below we will introduce the use scenario of the Valdr framework and the corresponding programming code and configuration. The use scenario of Valdr mainly includes the following aspects: 1. Verify the entity class: Valdr can be used to verify the legitimacy of each field of the physical class.For example, a person's age field can only be used between 0 and 150. Valdr can easily define the verification rules of the field. Programming code example: public class Person { @Min(0) @Max(150) private int age; // omit other fields and methods } In the above examples, the `@min` and@max` annotations provided by Valdr are used to specify the verification rules of the age field. 2. Verify DTO (Data Transfer Object): In Web development, we often need to verify the data passed to the back end to the back -end data. DTO is a commonly used data transmission object.Use the Valdr framework to easily verify the fields in DTO. Programming code example: public class UserDTO { @NotEmpty private String username; @Email private String email; // omit other fields and methods } In the above examples, the user name and mailbox field are verified using the `@notempty` and@email` annotations provided by Valdr to verify the user name and mailbox field. 3. Verifying operating parameters: In some cases, we need to verify the parameters in the method.The Valdr framework helps us define and execute these verification logic. Programming code example: public void updateUser(@Valid @RequestBody UserDTO userDTO) { // Processing the logic of updating users } In the above examples, the `@vene annotation provided by the Spring framework to trigger the Valdr framework to verify the Valdr framework. Configure Valdr development environment: 1. Import the dependencies of Valdr: Add the following dependencies in the project's `pom.xml` file: <dependency> <groupId>io.probedock.valdr</groupId> <artifactId>valdr-bean-validation-core</artifactId> <Version> Version Number </version> </dependency> 2. Configure the verification rules of Valdr: Define the verification rules in the configuration file of the project.You can define it by writing the JSON file or using the annotation. Configuration example (using annotation method): @Configuration public class ValdrConfig { @Bean public ValdrConfigurer valdrConfigurer() { // Create Valdrconfigurer object and add custom verification rules ValdrConfigurer valdrConfigurer = new ValdrConfigurer(); valdrConfigurer.addAllowedPackage("com.example"); return valdrConfigurer; } } In the above examples, the verification rules under the `Valdrconfigurer` object are added. Summarize: Valdr Bean Validation's application scenarios in the Java library are widely used.By using VALDR, we can easily verify the legality of the physical class, DTO, and method parameters.In addition, the configuration of VALDR is relatively simple, which can flexibly define the verification rules.It is hoped that this article will help the reader's understanding of the use of the Valdr framework.