com.cloudera.csd.validation.constraints.components.UniqueFieldValidatorImpl.java Source code

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Here is the source code for com.cloudera.csd.validation.constraints.components.UniqueFieldValidatorImpl.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.csd.validation.constraints.components;

import com.cloudera.csd.validation.constraints.UniqueField;
import com.cloudera.csd.validation.constraints.UniqueFieldValidator;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.Sets;

import java.beans.PropertyDescriptor;
import java.util.Collection;
import java.util.Set;
import javax.validation.ConstraintValidatorContext;
import javax.validation.ValidationException;

import org.apache.commons.beanutils.PropertyUtils;

/**
 * The implementation of the UniqueFieldValidator
 */
public class UniqueFieldValidatorImpl implements UniqueFieldValidator {

    private UniqueField uniqueField;
    private boolean skipNulls;

    @Override
    public void initialize(UniqueField constraintAnnotation) {
        this.uniqueField = constraintAnnotation;
        this.skipNulls = this.uniqueField.skipNulls();
    }

    @Override
    public boolean isValid(Collection<?> list, ConstraintValidatorContext context) {
        if (list != null) {
            Set<Object> seenSoFar = Sets.newHashSet();
            for (Object obj : list) {
                Object value = propertyValue(obj, uniqueField.value());
                if ((value == null) && this.skipNulls) {
                    continue;
                }
                if (seenSoFar.contains(value)) {
                    addViolation(context, uniqueField.value());
                    return false;
                }
                seenSoFar.add(value);
            }
        }
        return true;
    }

    /**
     * Adds a violation with the field in the context.
     * @param context the context
     * @param fieldName the field name.
     */
    @VisibleForTesting
    void addViolation(ConstraintValidatorContext context, String fieldName) {
        context.disableDefaultConstraintViolation();
        context.buildConstraintViolationWithTemplate(context.getDefaultConstraintMessageTemplate())
                .addPropertyNode(fieldName).inIterable().addConstraintViolation();
    }

    /**
     * @return return the value of the property
     */
    @VisibleForTesting
    Object propertyValue(Object obj, String property) {
        try {
            PropertyDescriptor desc = PropertyUtils.getPropertyDescriptor(obj, property);
            return desc.getReadMethod().invoke(obj, new Object[] {});
        } catch (Exception e) {
            throw new ValidationException(e);
        }
    }
}