每日一博 | SpringBoot 使用 velocity 模板引擎

第五章 使用velocity模板引擎

最爽的Web组合开发就是Intellij IDEA + Maven + Spring Boot + Scala + Velocity + Boostrap + jQuery了.

Spring Boot提供了一个强大的一键式Spring的集成开发环境，能够单独进行一个Spring应用的开发，其中：

（1）集中式配置（application.properties）+注解，大大简化了开发流程

（2）内嵌的Tomcat和Jetty容器，可直接打成jar包启动，无需提供Java war包以及繁琐的Web配置

（3）提供了Spring各个插件的基于Maven的pom模板配置，开箱即用，便利无比。

（4）可以在任何你想自动化配置的地方，实现可能

（5）提供更多的企业级开发特性，如何系统监控，健康诊断，权限控制

（6）无冗余代码生成和XML强制配置

（7）提供支持强大的Restfult风格的编码，非常简洁

当然Spring Boot提供的功能，远远比上面的强大. Spring boot集成了servlet容器，当我们在pom文件中增加spring-boot-starter-web的maven依赖时，不做任何web相关的配置便能提供web服务，这还得归于spring boot 自动配置的功能（因为加了EnableAutoConfiguration的注解），帮我们创建了一堆默认的配置，以前在web.xml中配置，现在都可以通过spring bean的方式进行配置，由spring来进行生命周期的管理，大多数情况下，我们需要重载这些配置（例如修改服务的启动端口，contextpath,filter,listener,servlet,session超时时间等）

本章我们介绍一下,在SB中使用模板引擎Velocity.

SB默认支持的模板引擎

spring boot会自动配置 FreeMarker,Thymeleaf,Velocity，只需要在pom中加入相应的依赖即可

SB使用Velocity的依赖

` <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-velocity</artifactId> </dependency>

`

默认配置下spring boot会从src/main/resources/templates目录中去找模板

SB的velocity配置

application.properties配置

lightsword/src/main/resources/application.properties

```

VELOCITY TEMPLATES (VelocityAutoConfiguration)

spring.velocity.charset=UTF-8 spring.velocity.properties.input.encoding=UTF-8 spring.velocity.properties.output.encoding=UTF-8 spring.velocity.resourceLoaderPath=classpath:/templates/ spring.velocity.suffix=.html spring.velocity.toolbox-config-location=/WEB-INF/toolbox.xml

```

这样,SB会从src/main/resources/templates目录中去找以.html后缀的模板文件.

Controller里面的Model

数据httpapis通过model传到模板文件(SpringMVC框架里面做的事情):

` model.addAttribute("httpapis", HttpApiDao.findAll())

`

完整的Controller代码:

https://github.com/LightSwordSpringBoot/lightsword/blob/lightsword/src/main/scala/com/springboot/in/action/controller/HttpApiController.scala

``` package com.springboot.in.action.controller

import java.util.Date import java.util.concurrent.CountDownLatch

import com.alibaba.fastjson.JSON import com.springboot.in.action.dao.{HttpApiDao, HttpReportDao, HttpSuiteDao} import com.springboot.in.action.engine.OkHttp import com.springboot.in.action.entity.{HttpApi, HttpReport} import org.springframework.beans.factory.annotation.Autowired import org.springframework.ui.Model import org.springframework.web.bind.annotation.{PathVariable, RequestMapping, RequestMethod, RequestParam, ResponseBody, RestController} import org.springframework.web.servlet.ModelAndView import scala.collection.JavaConversions._

@RestController @RequestMapping(Array("/httpapi")) class HttpApiController @Autowired() ( val HttpSuiteDao: HttpSuiteDao, val HttpApiDao: HttpApiDao, val HttpReportDao: HttpReportDao) {

@RequestMapping(value = { Array("", "/") }, method = Array(RequestMethod.GET)) def list(model: Model) = { model.addAttribute("httpapis", HttpApiDao.findAll()) new ModelAndView("/httpapi/list") }

...

}

```

模板文件list.html

lightsword/src/main/resources/templates/httpapi/list.html

```

include("/common/header.html")

</tr>         #end     </tbody> </table>

include("/common/footer.html")

```

velocity的语法详情参考:

toolbox的使用

我们在velocity模板文件中有时候需要格式化小数点,日期等输出,我们可以使用toolbox.

我们看到application.properties有这么一行配置:

``` spring.velocity.toolbox-config-location=/WEB-INF/toolbox.xml

```

然后,在list.html里面有这么一行代码

` <td>$!DateTool.format('yyyy-MM-dd HH:mm:ss', $!t.gmtModify)</td>

`

这个DateTool就是我们这里要说的toolbox的功能.

lightsword/src/main/resources/WEB-INF/toolbox.xml的配置如下

```

<!-- [ DateTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/generic/DateTool.html      (ja) @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/DateTool.html      (en) @since VelocityTools 1.0 --> <tool>     <key>DateTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.DateTool</class> </tool>  <!-- [ MathTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/generic/MathTool.html      (ja) @see http://velocity.apache.org/tools/devel/generic/MathTool.html (en)      @since VelocityTools 1.0 --> <tool>     <key>MathTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.MathTool</class> </tool>  <!-- [ NumberTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/NumberTool.html      (en) @since VelocityTools 1.2 --> <tool>     <key>NumberTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.NumberTool</class> </tool>  <!-- [ RenderTool ] @see http://velocity.apache.org/tools/devel/generic/RenderTool.html      (en) @since VelocityTools 1.0 <tool> <key>render</key> <scope>application</scope>      <class>org.apache.velocity.tools.generic.RenderTool</class> </tool> -->  <!-- [ EscapeTool ] @see http://velocity.apache.org/tools/devel/generic/EscapeTool.html      (en) @since VelocityTools 1.2 --> <tool>     <key>EscapeTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.EscapeTool</class> </tool>  <!-- [ ResourceTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/ResourceTool.html      (en) @since Velocity 1.3 <tool> <key>text</key> <class>org.apache.velocity.tools.generic.ResourceTool</class>      <parameter name="bundles" value="resources,prj.hoboken.patrasche.resources.PatrascheResources"      /> <parameter name="locale" value="ja_JP" /> </tool> -->  <!-- [ AlternatorTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/AlternatorTool.html      (en) @since VelocityTools 1.2 --> <tool>     <key>AlternatorTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.AlternatorTool</class> </tool>  <!-- [ ValueParser ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/ValueParser.html      (en) @since VelocityTools 1.2 --> <tool>     <key>ValueParser</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.ValueParser</class> </tool>  <!-- [ ListTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/ListTool.html      (en) @since VelocityTools 1.2 --> <tool>     <key>ListTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.ListTool</class> </tool>  <!-- [ SortTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/SortTool.html      (en) @since VelocityTools 1.2 --> <tool>     <key>SortTool</key>     <scope>application</scope>     <class>org.apache.velocity.tools.generic.SortTool</class> </tool>  <!-- [ IteratorTool ] @see http://velocity.apache.org/tools/devel/javadoc/org/apache/velocity/tools/generic/IteratorTool.html      (en) @since VelocityTools 1.0 --> <tool>     <key>IteratorTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.generic.IteratorTool</class> </tool>  <!-- ============================================================ [ TOOL      FOR STRUTS TAGLIB ] ============================================================ --> <!-- [ ActionMessagesTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/ActionMessagesTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/ActionMessagesTool.html      (en) @since VelocityTools 1.1 --> <tool>     <key>ActionMessagesTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.ActionMessagesTool</class> </tool>  <!-- [ ErrorsTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/ErrorsTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/ErrorsTool.html (en)      @since VelocityTools 1.0 --> <tool>     <key>ErrorsTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.ErrorsTool</class> </tool>  <!-- [ FormTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/FormTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/FormTool.html (en)      @since VelocityTools 1.0 --> <tool>     <key>FormTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.FormTool</class> </tool>  <!-- [ MessageTool ] @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/MessageTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/MessageTool.html      (en) @since VelocityTools 1.0 --> <tool>     <key>MessageTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.MessageTool</class> </tool>  <!-- [ StrutsLinkTool ] LinkTool @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/StrutsLinkTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/StrutsLinkTool.html      (en) @since VelocityTools 1.0 --> <tool>     <key>StrutsLinkTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.StrutsLinkTool</class> </tool>  <!-- [ SecureLinkTool ] LinkTool @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/SecureLinkTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/SecureLinkTool.html      (en) @since VelocityTools 1.1 --> <tool>     <key>SecureLinkTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.SecureLinkTool</class> </tool>  <!-- [ TilesTool ] Tiles @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/TilesTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/TilesTool.html (en)      @since VelocityTools 1.1 --> <tool>     <key>TilesTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.TilesTool</class> </tool>  <!-- [ ValidatorTool ] Validator @see http://www.jajakarta.org/velocity/tools/velocity-tools-1.1/docs-ja/struts/ValidatorTool.html      (ja) @see http://velocity.apache.org/tools/devel/struts/ValidatorTool.html      (en) @since VelocityTools 1.1 --> <tool>     <key>ValidatorTool</key>     <scope>request</scope>     <class>org.apache.velocity.tools.struts.ValidatorTool</class> </tool>

```

这样我们就可以在模板文件中使用类似DateTool这样的工具类了.同时我们也可以在代码里自己实现工具类,然后配置到toolbox.xml文件里.