Service Validation

NullSafe and DTO validation for Bean Validation in service layer using Aspect.

Build and Install

$ ./mvnw clean install

How to use

<dependency>
    <groupId>io.github.opensanca</groupId>
    <artifactId>service-validator</artifactId>
    <version>1.1.0</version>
</dependency>

compile 'io.github.opensanca:service-validator:1.1.0'

Spring Boot projects

Service Validation provides a ServiceValidationAutoConfiguration.class that allowed Auto Configuration mechanism.

Spring Boot auto-configuration attempts to automatically configure your Spring application based on the jar dependencies that you have added. https://docs.spring.io/spring-boot/docs/current/reference/html/using-boot-auto-configuration.html

Non Spring Boot projects

Service Validation provides a ServiceValidatorImport.class that allowed easy way configure it.

@ComponentScan(basePackages={"seu.pacote","io.github.opensanca"})

@Configuration
@ComponentScan
@Import(ServiceValidatorImport.class)
public class AppConfig {
    //...
}

Extra configurations

Because we use Bean Validation 1.1 JSR 349, you have to ensure there is a provider for this specification available in your classpath, such as Hibernate Validator or Apache BVal. Note that if you are using a JEE-compliant application server like WildFly or TomEE you already have one.

The absence of providers cause this error during Spring context startup:

javax.validation.ValidationException: 
Unable to create a Configuration, because no Bean Validation provider could be found. 
Add a provider like Hibernate Validator (RI) to your classpath.

***************************
APPLICATION FAILED TO START
***************************

Description:

The Bean Validation API is on the classpath but no implementation could be found

Action:

Add an implementation, such as Hibernate Validator, to the classpath

Additionally, some Bean Validation providers may have dependencies of their own, like the Expression Language API, causing similar bootstrap errors like the following:

Caused by: javax.validation.ValidationException: HV000183: Unable to initialize 'javax.el.ExpressionFactory'. 
Check that you have the EL dependencies on the classpath, or use ParameterMessageInterpolator instead

We recommended to use Glassfish Web EL Implementation in this case. Note that EL is also part of the JEE stack, so you can safely ignore this if you're running a full-fledged application server.

Samples

public class DTO {

    @NotNull
    private String text;

    @Max(10)
    private Integer number;

    public void setNumber(Integer number) {
        this.number = number;
    }

    public void setText(String text) {
        this.text = text;
    }
}

Validate Javax Validations Constraints and NullSafe.

@Component
public class MyComponent {

    @ServiceValidation
    public void doSomething(final DTO dto) {

    }
}

Validate Javax Validations Constraints only.

@Component
public class MyComponent {

    @ServiceValidation(nullSafe = false)
    public void doSomething(final DTO dto) {

    }
}

Validate NullSafe arguments only.

@Component
public class MyComponent {

    @ServiceValidation(javaxValidation = false)
    public void doSomething(final DTO dto) {

    }
}

Don't do this! ¬¬

@Component
public class MyComponent {

    @ServiceValidation(nullSafe = false, javaxValidation = false) //Don't do this!
    public void youDontNeedThis(DTO dto) {

    }
}

Spring MVC

There is an @ExceptionHandler bundled in this library that automatically translates ServiceValidationException's to JSON. So you don't need to bother writing your own should you decide to leverage this exception as an interface with your API clients.

Testing Violations

ServiceValidator provides custom org.hamcrest.Matchers that allowed testing violations of ServiceValidationErrorCollection.class.

errorCollectionHasSize
errorCollectionHasViolation

import static io.github.opensanca.matchers.ServiceValidatorErrorMatcher.errorCollectionHasSize;
import static io.github.opensanca.matchers.ServiceValidatorViolationsMatcher.errorCollectionHasViolation;

@RunWith(SpringRunner.class)
public class CoolTest {
    
    @Rule
    public ExpectedException exception = ExpectedException.none();

    @Test
    public void someCoolTest() {
        exception.expect(ServiceValidationException.class);
        exception.expect(errorCollectionHasSize(1));
        exception.expect(errorCollectionHasViolation("DTO.text", "may not be null"));
        exception.expect(errorCollectionHasViolation("DTO.text", "may not be empty"));
        //
    }
}

opensanca/service-validator