com.speedment.common.injector.internal.util.PropertiesUtil Maven / Gradle / Ivy

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/*
 *
 * Copyright (c) 2006-2020, Speedment, 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.speedment.common.injector.internal.util;

import com.speedment.common.injector.InjectorProxy;
import com.speedment.common.injector.annotation.Config;
import com.speedment.common.injector.exception.InjectorException;
import com.speedment.common.logger.Logger;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.util.Properties;

import static com.speedment.common.injector.internal.util.ReflectionUtil.traverseFields;
import static java.util.Objects.requireNonNull;

/**
 *
 * @author Emil Forslund
 * @since  1.2.0
 */
public final class PropertiesUtil {

    private PropertiesUtil() {}

    public static Properties loadProperties(Logger logger, File configFile) {
        final Properties properties = new Properties();
        if (configFile.exists() && configFile.canRead()) {

            try (final InputStream in = new FileInputStream(configFile)) {
                properties.load(in);
            } catch (final IOException ex) {
                final String err = "Error loading default settings from " + configFile.getAbsolutePath() + "-file.";
                logger.error(ex, err);
                throw new InjectorException(err, ex);
            }
        } else {
            logger.info(
                "No configuration file '"
                + configFile.getAbsolutePath() + "' found."
            );
        }

        return properties;
    }
    
    public static  void configureParams(T instance, Properties properties, InjectorProxy injectorProxy) {
        requireNonNull(instance);
        requireNonNull(properties);
        requireNonNull(injectorProxy);

        traverseFields(instance.getClass())
            .filter(f -> f.isAnnotationPresent(Config.class))
            .forEach(f -> configure(instance, properties, injectorProxy, f));
    }

    private static  void configure(T instance, Properties properties, InjectorProxy injectorProxy, Field f) {
        final Config config = f.getAnnotation(Config.class);

        final String serialized;
        if (properties.containsKey(config.name())) {
            serialized = properties.getProperty(config.name());
        } else {
            serialized = config.value();
        }

        trySetField(instance, f, serialized, injectorProxy, config);
    }

    private static  void trySetField(T instance, Field f, String serialized, InjectorProxy injectorProxy, Config config) {
        ReflectionUtil.parse(f.getType(), serialized)
            .ifPresent(object -> {
                try {
                    injectorProxy.set(f, instance, object);
                } catch (final ReflectiveOperationException ex) {
                    throw new InjectorException(
                        "Failed to set config parameter '" + config.name() +
                            "' in class '" + instance.getClass().getName() +
                            "'.", ex
                    );
                }
            });
    }

}