code: private void validate() throws MojoExecutionException {
  		if ((file == null && libId == null) || (file != null && libId != null)) {
  			getLog()
  					.warn(
  							"You specified <file> and <libId>.  The <libId> always wins.");
  		}
  
  		// check that COM target exists
  		if (file != null && !file.exists()) {
  			getLog().warn("Can't find file: " + file);
  			throw new MojoExecutionException(
  					"The native COM target file couldn't be found: " + file);
  		}
  	}
docs: Check the configuration from the pom.xml
  
  @throws MojoExecutionException