ValidationInterceptor.java

/**
 * JBoss, Home of Professional Open Source
 *
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jboss.seam.validation;

import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Set;

import javax.inject.Inject;
import javax.interceptor.AroundInvoke;
import javax.interceptor.Interceptor;
import javax.interceptor.InvocationContext;
import javax.validation.Validator;

import org.hibernate.validator.MethodConstraintViolation;
import org.hibernate.validator.MethodConstraintViolationException;
import org.hibernate.validator.MethodValidator;

@AutoValidating
@Interceptor
public class ValidationInterceptor
{

   @Inject
   private Validator validator;

   @AroundInvoke
   public Object validateMethodInvocation(InvocationContext ctx) throws Exception
   {

      Set<MethodConstraintViolation<Object>> violations = validator.unwrap(MethodValidator.class).validateParameters(ctx.getTarget(), ctx.getMethod(), ctx.getParameters());

      if (!violations.isEmpty())
      {
         throw new MethodConstraintViolationException(getMessage(ctx.getMethod(), ctx.getParameters(), violations), violations);
      }

      Object result = ctx.proceed();

      violations = validator.unwrap(MethodValidator.class).validateReturnValue(ctx.getTarget(), ctx.getMethod(), result);

      if (!violations.isEmpty())
      {
         throw new MethodConstraintViolationException(getMessage(ctx.getMethod(), ctx.getParameters(), violations), violations);
      }

      return result;
   }

   private String getMessage(Method method, Object[] args, Set<? extends MethodConstraintViolation<?>> violations)
   {

      StringBuilder message = new StringBuilder();
      message.append(violations.size());
      message.append(" constraint violation(s) occurred during method invocation.");
      message.append("\nMethod: ");
      message.append(method);
      message.append("\nArgument values: ");
      message.append(Arrays.toString(args));
      message.append("\nConstraint violations: ");

      int i = 1;
      for (MethodConstraintViolation<?> oneConstraintViolation : violations)
      {
         message.append("\n  (");
         message.append(i);
         message.append(") Kind: ");
         message.append(oneConstraintViolation.getKind());
         message.append("\n      parameter index: ");
         message.append(oneConstraintViolation.getParameterIndex());
         message.append("\n      message: ");
         message.append(oneConstraintViolation.getMessage());
         message.append("\n      root bean: ");
         message.append(oneConstraintViolation.getRootBean());
         message.append("\n      property path: ");
         message.append(oneConstraintViolation.getPropertyPath());
         message.append("\n      constraint: ");
         message.append(oneConstraintViolation.getConstraintDescriptor().getAnnotation());

         i++;
      }

      return message.toString();
   }

}