com.turn.splicer.Config.java Source code

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Here is the source code for com.turn.splicer.Config.java

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/**
 * Copyright 2015-2016 The Splicer Query Engine 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 com.turn.splicer;

import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import java.util.Properties;
import java.util.TreeMap;

import com.fasterxml.jackson.core.JsonGenerator;
import com.google.common.base.Splitter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Config {

    private static final Logger LOG = LoggerFactory.getLogger(Config.class);

    private static final String CONFIG_FILE = "splicer.conf";

    private static final String VERSION_FILE = "VERSION";

    private static Splitter COMMA_SPLITTER = Splitter.on(',').omitEmptyStrings().trimResults();

    private static final Config INSTANCE = new Config();

    protected Properties properties = new Properties();

    private Config() {
        try {
            InputStream is = getClass().getClassLoader().getResourceAsStream(CONFIG_FILE);
            if (is != null) {
                LOG.info("Loaded {} bytes of configuration", is.available());
            }

            properties.load(is);
        } catch (IOException e) {
            LOG.error("Could not load " + CONFIG_FILE, e);
        }
    }

    public static Config get() {
        return INSTANCE;
    }

    /**
     * Read an integer from the config file
     * @param field property name
     * @return integer or throws NumberFormatException if property doesn't
     *         exist or is not an integer
     */
    public int getInt(String field) {
        return Integer.parseInt(properties.getProperty(field));
    }

    /**
     * Read an integer from the config file
     * @param field property name
     * @param defaultVal default to return if no property
     * @return integer or defaultVal if property doesn't exist or is not an
     *          integer
     */
    public int getInt(String field, int defaultVal) {
        try {
            return Integer.parseInt(properties.getProperty(field));
        } catch (NumberFormatException e) {
            return defaultVal;
        }
    }

    public boolean getBoolean(String field) {
        return Boolean.parseBoolean(properties.getProperty(field));
    }

    /**
     * Read a string from the config file
     * @param field property name
     * @return string or null if property doesn't exist
     */
    public String getString(String field) {
        return properties.getProperty(field);
    }

    /**
     * For properties of the form:
     *
     * key = value1,value2,value3....valuek
     * this will return an iterable of the values.
     *
     * @param field property name
     * @return list of (value1, value2... valuek)
     */
    public Iterable<String> getStrings(String field) {
        String all = getString(field);
        return COMMA_SPLITTER.split(all);
    }

    public void writeAsJson(JsonGenerator jgen) throws IOException {
        if (properties == null) {
            jgen.writeStartObject();
            jgen.writeEndObject();
            return;
        }

        TreeMap<String, String> map = new TreeMap<>();
        for (Map.Entry<Object, Object> e : properties.entrySet()) {
            map.put(String.valueOf(e.getKey()), String.valueOf(e.getValue()));
        }

        InputStream is = getClass().getClassLoader().getResourceAsStream(VERSION_FILE);
        if (is != null) {
            LOG.debug("Loaded {} bytes of version file configuration", is.available());
            Properties versionProps = new Properties();
            versionProps.load(is);
            for (Map.Entry<Object, Object> e : versionProps.entrySet()) {
                map.put(String.valueOf(e.getKey()), String.valueOf(e.getValue()));
            }
        } else {
            LOG.error("No version file found on classpath. VERSION_FILE={}", VERSION_FILE);
        }

        jgen.writeStartObject();
        for (Map.Entry<String, String> e : map.entrySet()) {
            if (e.getValue().indexOf(',') > 0) {
                splitList(e.getKey(), e.getValue(), jgen);
            } else {
                jgen.writeStringField(e.getKey(), e.getValue());
            }
        }
        jgen.writeEndObject();
    }

    private void splitList(String key, String value, JsonGenerator jgen) throws IOException {
        jgen.writeArrayFieldStart(key);
        for (String o : value.split(",")) {
            jgen.writeString(o);
        }
        jgen.writeEndArray();
    }

}