code: private static com.jfinal.template.Engine createEngine(TemplateConfig config) {
  		Assert.notNull(config, "Template config is null !");
  		final com.jfinal.template.Engine engine = com.jfinal.template.Engine.create("Hutool-Enjoy-Engine-" + config.toString());
  		engine.setEncoding(config.getCharsetStr());
  
  		switch (config.getResourceMode()) {
  		case STRING:
  			// 默认字符串类型资源:
  			break;
  		case CLASSPATH:
  			engine.setToClassPathSourceFactory();
  			engine.setBaseTemplatePath(config.getPath());
  			break;
  		case FILE:
  			engine.setSourceFactory(new FileSourceFactory());
  			engine.setBaseTemplatePath(config.getPath());
  			break;
  		case WEB_ROOT:
  			engine.setSourceFactory(new FileSourceFactory());
  			engine.setBaseTemplatePath(FileUtil.getAbsolutePath(FileUtil.getWebRoot()));
  			break;
  		default:
  			break;
  		}
  
  		return engine;
  	}
docs: 创建引擎
  
  @param config 模板配置
  @return {@link GroupTemplate}