package com.github.valfirst.slf4jtest;
   
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.UncheckedIOException;
   import java.util.Properties;
   
   class OverridableProperties {
       private static final Properties EMPTY_PROPERTIES = new Properties();
      private final String propertySourceName;
      private final Properties properties;
  
      OverridableProperties(final String propertySourceName) throws IOException {
          this.propertySourceName = propertySourceName;
          this.properties = getProperties();
      }
  
      private Properties getProperties() throws IOException {
          InputStream resourceAsStream =
                  Thread.currentThread()
                          .getContextClassLoader()
                          .getResourceAsStream(propertySourceName + ".properties");
          if (resourceAsStream != null) {
              return loadProperties(resourceAsStream);
          }
          return EMPTY_PROPERTIES;
      }
  
      private static Properties loadProperties(InputStream propertyResource) throws IOException {
          try (InputStream closablePropertyResource = propertyResource) {
              final Properties loadedProperties = new Properties();
              loadedProperties.load(closablePropertyResource);
              return loadedProperties;
          }
      }
  
      String getProperty(final String propertyKey, final String defaultValue) {
          final String propertyFileProperty = properties.getProperty(propertyKey, defaultValue);
          return System.getProperty(propertySourceName + "." + propertyKey, propertyFileProperty);
      }
  
      public static OverridableProperties createUnchecked(final String propertySourceName) {
          try {
              return new OverridableProperties(propertySourceName);
          } catch (IOException e) {
              throw new UncheckedIOException(e);
          }
      }
  }