code: private static InputStreamReader decompressWith7Zip(final String archivePath)
  		throws ConfigurationException
  	{
  		PATH_PROGRAM_7ZIP = (String) config
  					.getConfigParameter(ConfigurationKeys.PATH_PROGRAM_7ZIP);
  
  		if (PATH_PROGRAM_7ZIP == null) {
  			throw ErrorFactory
  					.createConfigurationException(ErrorKeys.CONFIGURATION_PARAMETER_UNDEFINED);
  		}
  
  		try {
  			Runtime runtime = Runtime.getRuntime();
  			Process p = runtime.exec(PATH_PROGRAM_7ZIP + " e " + archivePath
  					+ " -so");
  
  			return new InputStreamReader(p.getInputStream(), WIKIPEDIA_ENCODING);
  
  		}
  		catch (Exception e) {
  			throw new RuntimeException(e);
  		}
  	}
docs: Starts a decompression process using the 7Zip program.
  
  @param archivePath
  path to the archive
  @return InputStreamReader
  
  @throws ConfigurationException
  if an error occurred while accessing the configuration