How to use FreeMarker
This article mainly introduces the relevant knowledge of "how to use FreeMarker". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how to use FreeMarker" can help you solve the problem.
First, what is the static page
When visiting details pages such as news, event items, etc., the path can be xx [id]. Html, the server dynamically generates html web pages according to the request id. The next time you visit the data, you do not need to query the data, and directly return the html static page-reduce the data base to each other, and improve the query ability.
2. Use the technology Freemarker
Here, because I am using Struts2, the default is to use freemarker to implement a custom tag template, and the project imports struts2 and has already imported the freemarker jar package.
2.1What is Freemarke
FreeMarker is a template engine: a general tool based on templates and data to be changed and used to generate output text (HTML pages, e-mails, configuration files, source code, etc.). It is not for end users, but a Java class library, a component that programmers can embed in the products they develop.
Template file + Java data object = output (text in any format)
Freemarker template file, usually with an extension. Ftl (use. Html .jsp is fine)
2.2 install the freemarker eclipse editing plug-in
Copy "freemarker_eclipseplugin" to eclipse's dropins folder and restart the development tool
2.2.1 Editing the template file for freemarker
Template files are usually placed under WEB-INF or classes
III. Simple introduction to Freemarker
3.1Create a simple Freemarker template file
${variable}, you need to specify the variable in the program and merge it into the template file for output.
3.3 write a test class
Package cn.hj.freemarker
Import java.io.File
Import java.io.IOException
Import java.io.PrintWriter
Import java.util.HashMap
Import java.util.Map
Import org.junit.Test
Import freemarker.template.Configuration
Import freemarker.template.Template
Import freemarker.template.TemplateException
Public class FreemarkerTest {
@ Test
Public void testOutput () throws IOException, TemplateException {
/ / configuration object, configuration template location
Configuration configuration=new Configuration (
Configuration.VERSION_2_3_22)
Configuration.setDirectoryForTemplateLoading (new File (
"src/main/webapp/WEB-INF/templates"))
/ / get the template object
Template template=configuration.getTemplate ("hello.ftl")
/ / dynamic data object
Map paramterMap=new HashMap ()
ParamterMap.put ("title", "getting started with Freemarker")
ParamterMap.put ("msg", "Hello, this is the first Freemarker case!" )
/ / merge output
Template.process (paramterMap, new PrintWriter (System.out))
}
}
This is the end of the introduction to "how to use FreeMarker". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.
