SpringBoot+FreeMarker+SiteMesh环境

准备搭建SpringBoot+FreeMarker+SiteMesh的框架,选用了springBoot2.1版本,安装一些教程无脑复制粘贴,把maven依赖和freemarker配置凑齐

pom依赖

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.sitemesh/sitemesh -->
        <dependency>
            <groupId>org.sitemesh</groupId>
            <artifactId>sitemesh</artifactId>
            <version>3.0.1</version>
</dependency>

application

#server
server:
   servlet:
      context-path: /basis

#DB
#sqlserver
spring:
   datasource: ######
      driverClassName: #####
      url: ####
      username: ####
      password: ####
   mvc:
      view:
         prefix: classpath:/templates
         suffix: ftl
   freemarker:
      cache: false
      charset: UTF-8
      content-type: text/html
      suffix: .ftl
      check-template-location: true
      template-loader-path: classpath:/templates
      #expose-request-attributes: true
      #expose-session-attributes: true
      #expose-spring-macro-helpers: true
      #allow-request-override: true
      request-context-attribute: request
      settings:
         default_encoding: UTF-8
         output_encoding: UTF-8
         url_escaping_charset: UTF-8
         tag_syntax: auto_detect
         locale: zh_CN
         datetime_format: yyyy-MM-dd HH:mm:ss
         date_format: yyyy-MM-dd
         time_format: HH:mm:ss

freemarker注释掉的4行造成了给解决问题造成了很大的干扰
SiteMeshFilter

@WebFilter("/*")
public class SitemeshFilter extends ConfigurableSiteMeshFilter {
    Logger logger = LoggerFactory.getLogger(SitemeshFilter.class);
    @Override
    protected void applyCustomConfiguration(SiteMeshFilterBuilder builder) {
        //设置模板装饰的请求，参数（拦截的请求（可以采用通配符方式），装饰该请求的装饰模板）
        //index是一个页面模板放在src/main/resource/templates/decorators目录下
        builder
        .addDecoratorPath("/*", "/layouts/default")
        //可设置不同请求用不同模板装饰
        .addExcludedPath("/static/*") //白名单，不进行过滤的请求
        .addExcludedPath("/api/*")
        .addExcludedPath("/Images/*")
        .addExcludedPath("/Scripts/*")
        .addExcludedPath("/Styles/*")
        .addExcludedPath("/AjaxHandler/*")
        .addExcludedPath("/waiterChat/*")
        .addExcludedPath("/statistic")
        //.builder.addTagRuleBundles(new DivExtractingTagRuleBundle())  //用于添加自定义标签
        ;
        logger.info("------------ sitemeshFilter config-----------");
    }
}

粗暴的复制粘贴给后面带来了一系列的问题:

1. sitemesh 模板文件 default.ftl 放在 templates/layouts 目录下找不到,报404错误
2. 将 default.ftl 文件移到static 目录下则被识别为资源文件,浏览器访问变成下载保存

看源码sitemesh拦截到请求后,会在请求返回前通过forward方法请求模板文件
org.sitemesh.webapp.WebAppContext

/**
     * Dispatch to the actual path. This method can be overriden to provide different ways of dispatching
     * (such as cross web-app).
     */
    protected void dispatch(HttpServletRequest request, HttpServletResponse response, String path)
            throws ServletException, IOException {
        RequestDispatcher dispatcher = servletContext.getRequestDispatcher(path);
        if (dispatcher == null) {
            throw new ServletException("Not found: " + path);
        }
        dispatcher.forward(request, response);
    }

由于模板文件 default.ftl 在template 目录下,受资源访问的保护,必须提供一个访问入口

/**
     * 
     * siteMesh decorator 访问
     *
     * @param decorator 模板文件名
     * @return
     * 
     * @author ###
     * @date 2019年4月11日 下午4:06:15
     */
    @RequestMapping(value = "/layouts/{decorator}", method = RequestMethod.GET)
    public String decorator(@PathVariable String decorator) {
        return "/layouts/"+decorator;
    }

访问请求报错

javax.servlet.ServletException: Cannot expose request attribute 'request' because of an existing model object of the same name

将相关设置注释掉,使用默认设置,问题解决.

3. 碰到新问题,使用post提交数据时,服务器端 sitemesh 进行 forward请求后报错

Request method 'POST' not supported

重新修改sitemesh模板访问入口,支持对post请求的页面进行包装

    /**
     * 
     * siteMesh decorator 访问
     *
     * @param decorator 模板文件名
     * @return
     * 
     * @author ###
     * @date 2019年4月11日 下午4:06:15
     */
@RequestMapping(value = "/layouts/{decorator}",method = {RequestMethod.GET,RequestMethod.POST})
    public String decorator(@PathVariable String decorator) {
        return "/layouts/"+decorator;
    }

4. sitemesh3 中模板也无法加载目标body元素中的样式属性

<!-- sitemesh2中可用,但在sitemesh3无效 -->
<body <sitemesh:getProperty property="body.class" writeEntireProperty="1"/> >
    <sitemesh:body/>
</body>

<!-- sitemesh3中作者推荐的处理方法--> 
<body>
<input id="meta.body.id" type="hidden" value="<sitemesh:write property="body.id" />"/>
<input id="meta.body.class" type="hidden" value="<sitemesh:write property="body.class" />"/>
<script type="text/javascript">
    var bodyClass = document.getElementById('meta.body.class').value;
    var bodyId = document.getElementById('meta.body.id').value;
    if (bodyId) {
        document.body.id = bodyid;
    }
    if (bodyClass) {
        document.body.className = bodyClass;
    }
</script>
    <sitemesh:write property='body' />
</body>

sitemesh3已经在2015.5.29以后停止维护了,不知道有没有同样好用的易于后端开发人员上手的前端装饰组件 (´༎ຶД༎ຶ`)