How to specify external configuration file in java

Many times in my work, I hope that the configuration file can be released, so that the configuration can be separated from the business. In fact, there are many ways to put it, such as xml and properties. Here I will talk about how to use properties to achieve configuration files and business code. separation

import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.SystemConfiguration;
import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy;
import org.apache.commons.lang.StringUtils;
import org.slf4j.LoggerFactory;

import java.io.File;

/**
 * Created by shengjk1 on 2017/12/11
 */
public class ConfigManager {
    protected final static org.slf4j.Logger logger = LoggerFactory.getLogger(ConfigManager.class);

    private boolean autoReload;

    private static final String BASE_PATH;

    private static final String GLOBAL_CONFIG_PATH = "global.config.path";

    private static final String fileName="conf.properties";

    private static volatile PropertiesConfiguration prop =null;

    static{
        logger.info("开始初始化ConfigurationManager===================== ");
        SystemConfiguration sysConfig = new SystemConfiguration();
        String globalPath = sysConfig.getString(GLOBAL_CONFIG_PATH);
        logger.info("globalPath=======================  "+globalPath);
        if(StringUtils.isBlank(globalPath)){/**默认加载classpath下面的文件**/
            globalPath = Thread.currentThread().getContextClassLoader().getResource("conf.properties").getFile();
        }
        BASE_PATH=globalPath;
    }

    public ConfigManager(boolean autoReload) throws ConfigurationException {
        this.autoReload=autoReload;
        loadConfig();
    }

    public void loadConfig() throws ConfigurationException {
        if (null==prop){
            prop=new PropertiesConfiguration();
        }
        File file=new File(BASE_PATH);
        prop.setFile(file);
        prop.setAutoSave(false);
        if(autoReload){/**重载策略,5秒钟监视文件变化***/
            prop.setReloadingStrategy(new FileChangedReloadingStrategy());
        }
        prop.load();


    }


    /**
     * @param key
     * @return value
     */
    public  String getProperty(String key) {
        return prop.getString(key);
    }

    /**
     * 获取整数类型的配置项
     *
     * @param key
     * @return value
     */
    public  Integer getInteger(String key) {
        String value = getProperty(key);
        return Integer.valueOf(value);
    }

    /**
     * 获取布尔类型的配置项
     *
     * @param key
     * @return value
     */
    public  Boolean getBoolean(String key) {
        String value = getProperty(key);
        return Boolean.valueOf(value);
    }

    /**
     * 获取Long类型的配置项
     *
     * @param key
     * @return
     */
    public  Long getLong(String key) {
        String value = getProperty(key);
        return Long.valueOf(value);
    }


    private static class SingletonHelp {
        static ConfigManager instance;
        static {
            try {
                instance = new ConfigManager(true);
            } catch (ConfigurationException e) {
                logger.error("ConfigurationManager error" +e);
            }
        }
    }


    public static ConfigManager build(){
        return SingletonHelp.instance;
    }

}

When executing the jar package, java -jar -Dglobal.config.path=”configuration file location”, you can