org.springframework.geode.boot.autoconfigure.condition.OnMissingPropertyCondition.java Source code

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Here is the source code for org.springframework.geode.boot.autoconfigure.condition.OnMissingPropertyCondition.java

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/*
 * Copyright 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.geode.boot.autoconfigure.condition;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.stream.Collectors;

import org.apache.shiro.util.Assert;
import org.apache.shiro.util.StringUtils;
import org.springframework.boot.autoconfigure.condition.ConditionMessage;
import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.annotation.AnnotationAttributes;
import org.springframework.core.env.PropertyResolver;
import org.springframework.core.type.AnnotatedTypeMetadata;
import org.springframework.util.MultiValueMap;

/**
 * The {@link OnMissingPropertyCondition} class is a {@link SpringBootCondition}, Spring {@link Condition} type
 * asserting whether the specified, declared properties are missing.
 *
 * @author John Blum
 * @see org.springframework.boot.autoconfigure.condition.ConditionOutcome
 * @see org.springframework.boot.autoconfigure.condition.SpringBootCondition
 * @see org.springframework.context.annotation.Condition
 * @see org.springframework.context.annotation.ConditionContext
 * @see org.springframework.core.annotation.AnnotationAttributes
 * @see org.springframework.core.env.PropertyResolver
 * @see org.springframework.core.type.AnnotatedTypeMetadata
 * @see org.springframework.geode.boot.autoconfigure.condition.ConditionalOnMissingProperty
 * @since 1.0.0
 */
public class OnMissingPropertyCondition extends SpringBootCondition {

    @Override
    public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {

        String annotationName = ConditionalOnMissingProperty.class.getName();

        Collection<AnnotationAttributes> annotationAttributesCollection = toAnnotationAttributesFromMultiValueMap(
                metadata.getAllAnnotationAttributes(annotationName));

        PropertyResolver propertyResolver = getPropertyResolver(context);

        Collection<String> allMatchingProperties = new ArrayList<>();

        annotationAttributesCollection.forEach(annotationAttributes -> {

            List<String> propertyNames = collectPropertyNames(annotationAttributes);

            allMatchingProperties.addAll(findMatchingProperties(propertyResolver, propertyNames));
        });

        return determineConditionOutcome(allMatchingProperties);
    }

    @SuppressWarnings("unchecked")
    private <T extends Collection<AnnotationAttributes>> T toAnnotationAttributesFromMultiValueMap(
            MultiValueMap<String, Object> map) {

        List<AnnotationAttributes> annotationAttributesList = new ArrayList<>();

        map.forEach((key, value) -> {
            for (int index = 0, size = value.size(); index < size; index++) {

                AnnotationAttributes annotationAttributes = resolveAnnotationAttributes(annotationAttributesList,
                        index);

                annotationAttributes.put(key, value.get(index));
            }
        });

        return (T) annotationAttributesList;
    }

    private AnnotationAttributes resolveAnnotationAttributes(List<AnnotationAttributes> annotationAttributesList,
            int index) {

        if (index < annotationAttributesList.size()) {
            return annotationAttributesList.get(index);
        } else {
            AnnotationAttributes newAnnotationAttributes = new AnnotationAttributes();
            annotationAttributesList.add(newAnnotationAttributes);
            return newAnnotationAttributes;
        }
    }

    private PropertyResolver getPropertyResolver(ConditionContext context) {
        return context.getEnvironment();
    }

    private List<String> collectPropertyNames(AnnotationAttributes annotationAttributes) {

        String prefix = getPrefix(annotationAttributes);

        String[] names = getNames(annotationAttributes);

        return Arrays.stream(names).map(name -> prefix + name).collect(Collectors.toList());
    }

    private String[] getNames(AnnotationAttributes annotationAttributes) {

        String[] names = annotationAttributes.getStringArray("name");
        String[] values = annotationAttributes.getStringArray("value");

        Assert.isTrue(names.length > 0 || values.length > 0,
                String.format("The name or value attribute of @%s is required",
                        ConditionalOnMissingProperty.class.getSimpleName()));

        // TODO remove; not needed when using @AliasFor.
        /*
        Assert.isTrue(names.length * values.length == 0,
           String.format("The name and value attributes of @%s are exclusive",
        ConditionalOnMissingProperty.class.getSimpleName()));
        */

        return names.length > 0 ? names : values;
    }

    private String getPrefix(AnnotationAttributes annotationAttributes) {

        String prefix = annotationAttributes.getString("prefix");

        return StringUtils.hasText(prefix) ? prefix.trim().endsWith(".") ? prefix.trim() : prefix.trim() + "." : "";
    }

    private Collection<String> findMatchingProperties(PropertyResolver propertyResolver,
            List<String> propertyNames) {
        return propertyNames.stream().filter(propertyResolver::containsProperty).collect(Collectors.toSet());
    }

    private ConditionOutcome determineConditionOutcome(Collection<String> matchingProperties) {

        if (!matchingProperties.isEmpty()) {

            return ConditionOutcome.noMatch(ConditionMessage.forCondition(ConditionalOnMissingProperty.class)
                    .found("property already defined", "properties already defined").items(matchingProperties));
        }

        return ConditionOutcome.match();
    }
}