com.cloudera.validation.BeanConstraintValidatorFactory.java Source code

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Here is the source code for com.cloudera.validation.BeanConstraintValidatorFactory.java

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// Licensed to Cloudera, Inc. under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  Cloudera, Inc. licenses this file
// to you 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 com.cloudera.validation;

import com.google.common.collect.Iterators;

import java.util.NoSuchElementException;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorFactory;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

/**
 * A Constraint Validation Factory that uses a Spring bean factory
 * to construct validators.
 */
public class BeanConstraintValidatorFactory implements ConstraintValidatorFactory {

    private final ConfigurableListableBeanFactory beanFactory;

    public BeanConstraintValidatorFactory(ConfigurableListableBeanFactory beanFactory) {
        this.beanFactory = beanFactory;
    }

    @Override
    public <T extends ConstraintValidator<?, ?>> T getInstance(Class<T> key) {
        try {
            String beanName = getBeanName(key);
            if (!beanFactory.isPrototype(beanName)) {
                String msg = "Bean [%s] must be of prototype scope.";
                throw new IllegalArgumentException(String.format(msg, beanName));
            }
            return beanFactory.getBean(beanName, key);
        } catch (NoSuchElementException e) {
            // The factory does not know about the bean it creates it.
            return beanFactory.createBean(key);
        }
    }

    @Override
    public void releaseInstance(ConstraintValidator<?, ?> instance) {
        String beanName = getBeanName(instance.getClass());
        beanFactory.destroyBean(beanName, instance);
    }

    private String getBeanName(Class<?> key) {
        String[] beanNames = beanFactory.getBeanNamesForType(key);
        return Iterators.getOnlyElement(Iterators.forArray(beanNames));
    }
}