com.vmware.photon.controller.common.dcp.validation.NotBlankValidator.java Source code

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Here is the source code for com.vmware.photon.controller.common.dcp.validation.NotBlankValidator.java

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/*
 * Copyright 2015 VMware, Inc. All Rights Reserved.
 *
 * 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 com.vmware.photon.controller.common.dcp.validation;

import com.vmware.xenon.common.ServiceDocument;

import org.apache.commons.lang3.StringUtils;
import static com.google.common.base.Preconditions.checkState;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;

/**
 * This class implements a validator that checks if the {@link NotBlank}
 * annotation on a state object is honored.
 */
public enum NotBlankValidator {
    INSTANCE;

    public static void validate(ServiceDocument state) {
        try {
            Field[] declaredFields = state.getClass().getDeclaredFields();
            for (Field field : declaredFields) {
                Annotation[] declaredAnnotations = field.getDeclaredAnnotations();
                for (Annotation annotation : declaredAnnotations) {
                    if (annotation.annotationType() == NotBlank.class) {
                        checkState(null != field.get(state), String.format("%s cannot be null", field.getName()));
                        if (String.class.equals(field.getType())) {
                            checkState((StringUtils.isNotBlank((String) field.get(state))),
                                    String.format("%s cannot be blank", field.getName()));
                        }
                    }
                }
            }
        } catch (IllegalStateException e) {
            throw e;
        } catch (Throwable t) {
            throw new RuntimeException(t);
        }
    }
}