The application of the Kie Commons Validation framework in the Java class library (Application of Kie Commons Validation Framework in Java Class Libraries))
Kie Commons Validation framework is a widely used verification framework in the Java library.It provides a simple and powerful way to verify the correctness and legality of the data model.In this article, we will introduce the application of the Kie Commons value framework in the Java library and provide some Java code examples.
The Kie Commons Validation framework uses annotations to define verification rules based on annotations, and checks the effectiveness of the data model by runtime verification.Through annotations, developers can easily add verification rules without writing a large number of template code.
The following is several common application scenarios of the Kie Commons value framework in the Java library:
1. Verify the physical class
The Kie Commons Validation framework can verify the field of the physical class by adding appropriate annotations to the attributes of the physical class.For example, we can use @Notnull annotations to verify that a field cannot be empty, or use @Min and @max annotations to verify the range of the value of a field.The following is an example of verifying the physical class:
public class User {
@NotNull
private String username;
@Min(18)
@Max(99)
private int age;
// getters and setters
}
// Use Kie Commons Validation framework to verify the physical class
User user = new User();
ValidationResult validationResult = Validator.validate(user);
if (validationResult.isValid()) {
// Data model verification passes
} else {
// Data model verification is not approved, processing error information
for (ConstraintViolation violation : validationResult.getViolations()) {
System.out.println(violation.getMessage());
}
}
2. Verification method parameters
The Kie Commons value framework can also be used to verify the method parameters in the Java library.By adding appropriate verification annotations to the method parameter, the parameters of the passing method can be ensured that the parameters are in line with expectations.The following is an example for verifying method parameters:
public class MathUtils {
public static int divide(@Min(1) int dividend, @Min(1) int divisor) {
return dividend / divisor;
}
}
// Use Kie Commons Validation framework to verify the method parameters
ValidationResult validationResult = Validator.validateParameters(MathUtils.class.getMethod("divide", int.class, int.class), new Object[]{-5, 2});
if (validationResult.isValid()) {
// Parameter verification Pass, execute method
int result = MathUtils.divide(-5, 2);
} else {
// Parameter verification is not approved, processing error information
for (ConstraintViolation violation : validationResult.getViolations()) {
System.out.println(violation.getMessage());
}
}
3. Customized verification rules
Kie Commons Validation framework also allows developers to define their own verification rules.By creating a custom verification device and corresponding annotations, more complicated verification logic can be defined according to business needs.The following is an example of a custom verification rule:
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = EvenNumberValidator.class)
public @interface EvenNumber {
String message () default "field must be even";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class EvenNumberValidator implements ConstraintValidator<EvenNumber, Integer> {
@Override
public boolean isValid(Integer value, ConstraintValidatorContext context) {
return value % 2 == 0;
}
}
public class NumberEntity {
@EvenNumber
private int number;
// getters and setters
}
// Use custom verification rules to verify
NumberEntity entity = new NumberEntity();
entity.setNumber(5);
ValidationResult validationResult = Validator.validate(entity);
if (validationResult.isValid()) {
// Data model verification passes
} else {
// Data model verification is not approved, processing error information
for (ConstraintViolation violation : validationResult.getViolations()) {
System.out.println(violation.getMessage());
}
}
Summarize:
The Kie Commons Validation framework is a powerful Java verification framework that provides a simple and easy -to -use way to verify the data model in the Java library.By defining verification rules based on annotations, developers can easily add and expand verification logic.The above is an example of the Kie Commons Validation framework in the Java library. I hope to help you understand the usage and advantages of the framework.
