org.unitils.util.AnnotationConfigLoader Maven / Gradle / Ivy

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/*
 * Copyright 2008, Unitils.org
 * 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.unitils.util;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Set;

import org.unitils.core.UnitilsException;
import org.unitils.core.util.ResourceConfig;
import org.unitils.core.util.ResourceConfigLoader;
import org.unitils.orm.jpa.annotation.JpaEntityManagerFactory;

import static org.unitils.util.AnnotationUtils.getFieldsAnnotatedWith;
import static org.unitils.util.AnnotationUtils.getMethodsAnnotatedWith;

/**
 * Loads the configuration of a resource that is configured on a test object, by reading class, method or field
 * level annotations. Also supports custom configuration methods.
 * 
 * @author Filip Neven
 * @author Tim Ducheyne
 * @param 
 *     The annotation class used for configuring the resource on a test object
 * @param 
 *     The type of the resource configuration class
 */
abstract public class AnnotationConfigLoader
    implements ResourceConfigLoader {
    /**
     * The annotation class used for configuring the resource on a test object
     */
    protected Class annotationClass;

    /**
     * Creates a new instance for the given annotation class
     * 
     * @param annotationClass
     *     The class of the configuring annotation, not null
     */
    public AnnotationConfigLoader(Class annotationClass) {
        this.annotationClass = annotationClass;
    }

    /**
     * Loads the resource configuration for the given test object
     * 
     * @return The resource configuration, if available. Null if not.
     */
    @Override
    public CFG loadResourceConfig(Object testObject) {
        return getResourceConfig(testObject.getClass());
    }

    /**
     * @param testClass
     *     The test class, not null
     * @return The resource config object
     */
    protected CFG getResourceConfig(Class testClass) {
        // look for a class level configuring annotation
        Set configuringAnnotations = new HashSet<>();
        A annotation = testClass.getAnnotation(annotationClass);
        if (annotation != null && isConfiguringAnnotation(annotation)) {
            configuringAnnotations.add(annotation);
        }

        // look for a field level configuring annotation
        Set annotatedFields = getFieldsAnnotatedWith(testClass, annotationClass);
        for (Field field : annotatedFields) {
            annotation = field.getAnnotation(annotationClass);
            if (isConfiguringAnnotation(annotation)) {
                configuringAnnotations.add(annotation);
            }
        }

        // look for a method level configuring annotation
        Set annotatedMethods = getMethodsAnnotatedWith(testClass, annotationClass, false);
        for (Method annotatedMethod : annotatedMethods) {
            annotation = annotatedMethod.getAnnotation(annotationClass);
            if (isConfiguringAnnotation(annotation)) {
                configuringAnnotations.add(annotation);
            }
        }

        // look for a custom config method
        Method customConfigMethod = null;
        for (Method annotatedMethod : annotatedMethods) {
            if (isCustomConfigMethod(annotatedMethod)) {
                customConfigMethod = annotatedMethod;
            }
        }

        if (configuringAnnotations.size() > 1) {
            throw new UnitilsException("Class " + testClass.getSimpleName() + " has " + configuringAnnotations.size() + " configuring @"
                + annotationClass.getSimpleName() + " annotations. There can only be one such annotation per class.");
        }

        if (configuringAnnotations.size() == 0 && customConfigMethod == null) {
            if (Object.class.equals(testClass.getSuperclass())) {
                return null;
            }
            return getResourceConfig(testClass.getSuperclass());
        }

        return createResourceConfig(configuringAnnotations.iterator().next(), customConfigMethod);
    }

    /**
     * Either the given configuring annotation or custom config method must not be null (may also both be not-null)
     * 
     * @param configuringAnnotation
     *     Configuring annotation, if any
     * @param customConfigMethod
     *     Custom config method, if any
     * @return A new resource config object, given the configuring annotation and custom configuration method
     */
    abstract protected CFG createResourceConfig(A configuringAnnotation, Method customConfigMethod);

    /**
     * @param testClass
     *     The test class, not null
     * @return The test class's custom configuration method, if any
     */
    protected Method getCustomConfigMethod(Class testClass) {
        Set annotatedMethods = AnnotationUtils.getMethodsAnnotatedWith(testClass, JpaEntityManagerFactory.class);
        for (Method annotatedMethod : annotatedMethods) {
            if (isCustomConfigMethod(annotatedMethod)) {
                return annotatedMethod;
            }
        }
        return null;
    }

    /**
     * @param annotatedMethod
     *     A method annotated with {@link #annotationClass}
     * @return True if the given method is a custom configuration method
     */
    protected abstract boolean isCustomConfigMethod(Method annotatedMethod);

    /**
     * @param annotation
     *     Annotation of type {@link #annotationClass}
     * @return True if for the given annotation, the necessary attributes are filled so that it can be
     *     regarded as a configuring annotation
     */
    protected abstract boolean isConfiguringAnnotation(A annotation);
}