/**
* Copyright (c) 2012-2017, jcabi.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met: 1) Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer. 2) Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution. 3) Neither the name of the jcabi.com nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jcabi.aspects.aj;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Set;
import javax.validation.ConstraintViolation;
import javax.validation.ConstraintViolationException;
import javax.validation.Validation;
import javax.validation.Validator;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.ConstructorSignature;
import org.aspectj.lang.reflect.MethodSignature;
/**
* Validates method calls.
*
* <p>We do this manual processing of {@code javax.validation.constraints.*}
* annotations only because
* JSR-303 in its current version doesn't support method level validation
* (see its Appendix C). At the moment we don't support anything expect these
* two annotations. We think that it's better to wait for JSR-303.
*
* <p>The class is thread-safe.
*
* @author Yegor Bugayenko (yegor@tpc2.com)
* @version $Id: 9ad797469151a785e3924ccbeacf650711a96798 $
* @since 0.1.10
* @see <a href="http://beanvalidation.org/1.0/spec/#appendix-methodlevelvalidation">Appendix C</a>
* @see <a href="http://aspects.jcabi.com/jsr-303.html">How it works</a>
*/
@Aspect
@SuppressWarnings({ "PMD.CyclomaticComplexity", "PMD.TooManyMethods" })
public final class MethodValidator {
/**
* JSR-303 Validator.
*/
private final transient Validator validator = Validation
.buildDefaultValidatorFactory()
.getValidator();
/**
* Validate arguments of a method.
*
* <p>Try NOT to change the signature of this method, in order to keep
* it backward compatible.
*
* @param point Join point
* @checkstyle LineLength (3 lines)
*/
@Before("execution(* *(.., @(javax.validation.* || javax.validation.constraints.*) (*), ..))")
public void beforeMethod(final JoinPoint point) {
if (this.validator != null) {
this.validateMethod(
point.getThis(),
MethodSignature.class.cast(point.getSignature()).getMethod(),
point.getArgs()
);
}
}
/**
* Validate arguments of constructor.
*
* <p>Try NOT to change the signature of this method, in order to keep
* it backward compatible.
*
* @param point Join point
* @checkstyle LineLength (3 lines)
*/
@Before("preinitialization(*.new(.., @(javax.validation.* || javax.validation.constraints.*) (*), ..))")
public void beforeCtor(final JoinPoint point) {
if (this.validator != null) {
@SuppressWarnings("unchecked")
final Constructor<Object> constructor = (Constructor<Object>)
ConstructorSignature.class.cast(point.getSignature())
.getConstructor();
this.validateConstructor(
constructor,
point.getArgs()
);
}
}
/**
* Validate method response.
*
* <p>Try NOT to change the signature of this method, in order to keep
* it backward compatible.
*
* @param point Join point
* @param result Result of the method
* @since 0.7.11
*/
@AfterReturning
(
// @checkstyle LineLength (1 line)
pointcut = "execution(@(javax.validation.* || javax.validation.constraints.*) * *(..))",
returning = "result"
)
public void after(final JoinPoint point, final Object result) {
this.checkForViolations(
this.validator
.forExecutables()
.validateReturnValue(
point.getThis(),
new ImprovedJoinPoint(point).currentMethod(),
result
)
);
}
/**
* Validates method parameters.
* @param object Object at pointcut
* @param method Method at pointcut
* @param args Parameters of the method
*/
private void validateMethod(final Object object, final Method method,
final Object... args) {
this.checkForViolations(this.validator
.forExecutables()
.validateParameters(
object,
method,
args
)
);
}
/**
* Validates constructor parameters.
* @param ctr Constructor at pointcut
* @param args Parameters of the method
*/
private void validateConstructor(final Constructor<Object> ctr,
final Object... args) {
this.checkForViolations(
this.validator
.forExecutables()
.validateConstructorParameters(
ctr,
args
)
);
}
/**
* Checks if violations set is empty and throws a
* {@link ConstraintViolationException} if it isn't.
* @param violations JSR303 violations.
*/
private void checkForViolations(
final Set<ConstraintViolation<Object>> violations) {
if (!violations.isEmpty()) {
throw new ConstraintViolationException(
MethodValidator.pack(violations),
violations
);
}
}
/**
* Pack violations into string.
* @param errs All violations
* @return The full text
*/
private static String pack(
final Collection<ConstraintViolation<Object>> errs) {
final StringBuilder text = new StringBuilder(0);
for (final ConstraintViolation<?> violation : errs) {
if (text.length() > 0) {
text.append("; ");
}
text.append(violation.getMessage());
}
return text.toString();
}
}