spring-boot开发网站使用freemarker里的自定义标签方法

创建类实现 TemplateDirectiveModel 类

@Component
public class UserTopicDirective implements TemplateDirectiveModel {@Autowiredprivate UserService userService;@Autowiredprivate TopicService topicService;@Overridepublic void execute(Environment environment, Map map, TemplateModel[] templateModels,TemplateDirectiveBody templateDirectiveBody) throws TemplateException, IOException {Page<Topic> page = new PageImpl<>(new ArrayList<>());if (map.containsKey("username") && map.get("username") != null) {String username = map.get("username").toString();if (map.containsKey("p")) {int p = map.get("p") == null ? 1 : Integer.parseInt(map.get("p").toString());int limit = Integer.parseInt(map.get("limit").toString());User currentUser = userService.findByUsername(username);if (currentUser != null) {page = topicService.findByUser(p, limit, currentUser);}}}DefaultObjectWrapperBuilder builder = new DefaultObjectWrapperBuilder(Configuration.VERSION_2_3_25);environment.setVariable("page", builder.build().wrap(page));templateDirectiveBody.render(environment.getOut());}
}

创建配置类

@Component
public class FreemarkerConfig {@Autowiredprivate Configuration configuration;@Autowiredprivate UserTopicDirective userTopicDirective;@PostConstructpublic void setSharedVariable() throws TemplateModelException {configuration.setSharedVariable("user_topics_tag", userTopicDirective);}}

用法

跟自定义macro用法一样，直接使用 <@xx></@xx> 来使用即可，值就直接在 user_topics_tag 标签里传就可以了

<@user_topics_tag username='tomoya' p=1 limit=10><#list page.getContent() as topic><p>${topic.title!}</p></#list>
</@user_topics_tag>

扩展

FreemarkerConfig类不止可以加入自定义的标签，还可以加入系统自定义的变量等，下面举例说明

spring-boot里的配置文件

# application.yml
site:
  baseUrl: http://localhost:8080/

对应的类是 SiteConfig.java 要取里面的值，使用方法如下

@Autowired
private SiteConfig siteConfig;//...
siteConfig.getBaseUrl();

如果把siteConfig加入到freemarker的configuration里就可以直接在freemarker页面上使用变量了

@PostConstruct
public void setSharedVariable() throws TemplateModelException {configuration.setSharedVariable("site", siteConfig);configuration.setSharedVariable("user_topics_tag", userTopicDirective);
}

页面里就可以这样来取值

<a href="${site.bashUrl}">首页</a>

是不是很方便

参考