de.ks.option.properties.PropertiesOptionSource.java Source code

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Here is the source code for de.ks.option.properties.PropertiesOptionSource.java

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/**
 * Copyright [2014] [Christian Loehnert]
 *
 * 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 de.ks.option.properties;

import com.fasterxml.jackson.databind.ObjectMapper;
import de.ks.option.OptionSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.annotation.PostConstruct;
import javax.enterprise.inject.Alternative;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Properties;

@Alternative
public class PropertiesOptionSource implements OptionSource {
    private static final Logger log = LoggerFactory.getLogger(PropertiesOptionSource.class);
    public static final String PROPERTIES_FILENAME = "properties";

    private static final ObjectMapper mapper = new ObjectMapper();

    protected final Properties properties = new Properties();

    @PostConstruct
    protected void load() {
        String path = getPropertiesFile();
        File file = new File(path);
        if (file.exists()) {
            try (FileInputStream fileInputStream = new FileInputStream(file)) {
                properties.load(fileInputStream);
            } catch (IOException e) {
                throw new RuntimeException("Could not load properties from " + path);
            }
        }
    }

    protected static String getPropertiesFile() {
        String workingDir = System.getProperty("user.dir");
        if (workingDir.endsWith("bin")) {
            File parentFile = new File(workingDir).getParentFile();
            return parentFile.getPath() + File.separator + "options." + PROPERTIES_FILENAME;
        } else {
            return workingDir + File.separator + "options." + PROPERTIES_FILENAME;
        }
    }

    public static void cleanup() {
        String path = getPropertiesFile();
        if (new File(path).exists()) {
            try {
                Files.delete(Paths.get(path));
            } catch (IOException e) {
                log.error("Could not clean up {}", path, e);
            }
        }
    }

    @Override
    @SuppressWarnings("unchecked")
    public <T> T readOption(String path) {
        String stringValue = (String) properties.get(path);
        String className = (String) properties.get(path + "_clazz");

        if (stringValue == null) {
            return null;
        }

        try {
            Class<?> valueClass = Class.forName(className);
            Object o = mapper.readValue(stringValue, valueClass);
            return (T) o;
        } catch (ClassNotFoundException | IOException e) {
            log.error("Could not get option {}", path, e);
            return null;
        }
    }

    @Override
    public void saveOption(String path, Object value) {
        try {
            String valueAsString = mapper.writeValueAsString(value);
            properties.put(path, valueAsString);
            properties.put(path + "_clazz", value.getClass().getName());
            try (FileOutputStream stream = new FileOutputStream(new File(getPropertiesFile()))) {
                properties.store(stream, "");
            }
        } catch (IOException e) {
            throw new RuntimeException("Could not set option '" + path + "' and value=" + value, e);
        }
    }
}