/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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.springframework.validation.beanvalidation;

import java.util.Iterator;
import java.util.Set;
import javax.validation.ConstraintViolation;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;

import org.springframework.aop.framework.AopProxyUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

Simple BeanPostProcessor that checks JSR-303 constraint annotations in Spring-managed beans, throwing an initialization exception in case of constraint violations right before calling the bean's init method (if any). 
Author:
Juergen Hoeller
Since:
3.0/**
 * Simple {@link BeanPostProcessor} that checks JSR-303 constraint annotations
 * in Spring-managed beans, throwing an initialization exception in case of
 * constraint violations right before calling the bean's init method (if any).
 *
 * @author Juergen Hoeller
 * @since 3.0
 */
public class BeanValidationPostProcessor implements BeanPostProcessor, InitializingBean {

	@Nullable
	private Validator validator;

	private boolean afterInitialization = false;


	
Set the JSR-303 Validator to delegate to for validating beans.
Default is the default ValidatorFactory's default Validator.
/**
	 * Set the JSR-303 Validator to delegate to for validating beans.
	 * <p>Default is the default ValidatorFactory's default Validator.
	 */
	public void setValidator(Validator validator) {
		this.validator = validator;
	}

	
Set the JSR-303 ValidatorFactory to delegate to for validating beans,
using its default Validator.
Default is the default ValidatorFactory's default Validator.
See Also:
getValidator.getValidator()/**
	 * Set the JSR-303 ValidatorFactory to delegate to for validating beans,
	 * using its default Validator.
	 * <p>Default is the default ValidatorFactory's default Validator.
	 * @see javax.validation.ValidatorFactory#getValidator()
	 */
	public void setValidatorFactory(ValidatorFactory validatorFactory) {
		this.validator = validatorFactory.getValidator();
	}

	
Choose whether to perform validation after bean initialization
(i.e. after init methods) instead of before (which is the default).
Default is "false" (before initialization). Switch this to "true"
(after initialization) if you would like to give init methods a chance
to populate constrained fields before they get validated.
/**
	 * Choose whether to perform validation after bean initialization
	 * (i.e. after init methods) instead of before (which is the default).
	 * <p>Default is "false" (before initialization). Switch this to "true"
	 * (after initialization) if you would like to give init methods a chance
	 * to populate constrained fields before they get validated.
	 */
	public void setAfterInitialization(boolean afterInitialization) {
		this.afterInitialization = afterInitialization;
	}

	@Override
	public void afterPropertiesSet() {
		if (this.validator == null) {
			this.validator = Validation.buildDefaultValidatorFactory().getValidator();
		}
	}


	@Override
	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
		if (!this.afterInitialization) {
			doValidate(bean);
		}
		return bean;
	}

	@Override
	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
		if (this.afterInitialization) {
			doValidate(bean);
		}
		return bean;
	}


	
Perform validation of the given bean.
Params:
bean – the bean instance to validate
See Also:
Validator.validate/**
	 * Perform validation of the given bean.
	 * @param bean the bean instance to validate
	 * @see javax.validation.Validator#validate
	 */
	protected void doValidate(Object bean) {
		Assert.state(this.validator != null, "No Validator set");
		Object objectToValidate = AopProxyUtils.getSingletonTarget(bean);
		if (objectToValidate == null) {
			objectToValidate = bean;
		}
		Set<ConstraintViolation<Object>> result = this.validator.validate(objectToValidate);

		if (!result.isEmpty()) {
			StringBuilder sb = new StringBuilder("Bean state is invalid: ");
			for (Iterator<ConstraintViolation<Object>> it = result.iterator(); it.hasNext();) {
				ConstraintViolation<Object> violation = it.next();
				sb.append(violation.getPropertyPath()).append(" - ").append(violation.getMessage());
				if (it.hasNext()) {
					sb.append("; ");
				}
			}
			throw new BeanInitializationException(sb.toString());
		}
	}

}