io.github.benas.projector.processors.AbstractAnnotationProcessor.java Source code

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Here is the source code for io.github.benas.projector.processors.AbstractAnnotationProcessor.java

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/*
 *   The MIT License
 *
 *    Copyright (c) 2015, Mahmoud Ben Hassine (mahmoud@benhassine.fr)
 *
 *    Permission is hereby granted, free of charge, to any person obtaining a copy
 *    of this software and associated documentation files (the "Software"), to deal
 *    in the Software without restriction, including without limitation the rights
 *    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *    copies of the Software, and to permit persons to whom the Software is
 *    furnished to do so, subject to the following conditions:
 *
 *    The above copyright notice and this permission notice shall be included in
 *    all copies or substantial portions of the Software.
 *
 *    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *    THE SOFTWARE.
 */

package io.github.benas.projector.processors;

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.PropertyUtils;

import java.lang.reflect.Field;
import java.text.MessageFormat;

/**
 * Base class for {@link io.github.benas.projector.api.AnnotationProcessor} implementations providing common methods.
 *
 * @author Mahmoud Ben Hassine (mahmoud@benhassine.fr)
 */
public abstract class AbstractAnnotationProcessor {

    /**
     * Convert the value to field type and set it in the target object.
     *
     * @param target the target object
     * @param field the annotated field
     * @param key the annotation property attribute
     * @param value the value to inject
     * @throws Exception thrown if an exception occurs when trying to set the field value
     */
    protected void injectProperty(Object target, Field field, String key, Object value) throws Exception {

        Object typedValue = ConvertUtils.convert(value, field.getType());
        try {
            PropertyUtils.setProperty(target, field.getName(), typedValue);
        } catch (Exception e) {
            throw new Exception("Unable to set property " + key + " on field " + field.getName() + " of type "
                    + target.getClass() + ". A setter may be missing for this field.", e);
        }

    }

    /**
     * Constructs an error message to signal missing properties file.
     *
     * @param source the source file name
     * @param field the target field
     * @param object the target object
     * @return the formatted error message
     */
    protected String missingSourceFile(final String source, final Field field, final Object object) {
        return MessageFormat.format("Unable to load properties from source {0} for field {1} of type {2}", source,
                field.getName(), object.getClass().getName());
    }

    /**
     * Constructs an error message to signal missing annotation attribute value.
     *
     * @param attribute the target attribute
     * @param annotation the annotation concerned
     * @param field the target field
     * @param object the target object
     * @return the formatted error message
     */
    protected String missingAttributeValue(final String attribute, final String annotation, final Field field,
            final Object object) {
        return MessageFormat.format(
                "No value specified for attribute {0} of {1} annotation on field {2} of type {3}", attribute,
                annotation, field.getName(), object.getClass().getName());
    }

}