Run the project, and you can see the effect in Http://localhost:8080/todo and Http://localhost:8080/todo/hi.
Below starts using the Velocity template engine, builds the directory templates under SRC, creates the file Test.vm in the Templates directory, and reads as follows:
<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 ">
<body>
#set ($this = "Velocity")
$this is great! <br/>
$name <br/>
Hi, I am Letian
</body>
Create a new Java file in the SRC directory Myvelocity01.java:
Copy Code code as follows:
Import java.io.*;
Import javax.servlet.*;
Import javax.servlet.http.*;
Import org.apache.velocity.app.Velocity;
Import Org.apache.velocity.app.VelocityEngine;
Import Org.apache.velocity.VelocityContext;
Import java.util.Properties;
public class MyVelocity01 extends HttpServlet {
@Override
public void doget (HttpServletRequest request, httpservletresponse response)
Throws IOException, Servletexception {
Request.setcharacterencoding ("UTF-8");
Response.setcontenttype ("Text/html;charset=utf-8");
PrintWriter out = Response.getwriter ();
Properties Properties=new properties ();
Properties.setproperty ("Resource.loader", "class");
Properties.setproperty ("Class.resource.loader.class", " Org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader ");
Properties.setproperty ("input.encoding", "UTF-8");
Properties.setproperty ("output.encoding", "UTF-8");
Properties.setproperty (Velocity.encoding_default, "UTF-8");
Properties.setproperty (velocity.input_encoding, "UTF-8");
Properties.setproperty (velocity.output_encoding, "UTF-8");
Velocityengine velocityengine = new Velocityengine (properties);
Velocitycontext context=new Velocitycontext ();
Context.put ("name", "Test");
StringWriter SW = new StringWriter ();
Velocityengine.mergetemplate ("Templates/test.vm", "utf-8", context, SW);
Velocityengine.mergetemplate ("Templates/test.vm", "utf-8", context, SW); That's going to happen two times.
Out.println (Sw.tostring ());
}
}
Configure Web.xml:
Copy Code code as follows:
<!--myvelocity-->
<servlet>
<servlet-name>ve</servlet-name>
<servlet-class>MyVelocity01</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ve</servlet-name>
<url-pattern>/ve</url-pattern>
</servlet-mapping>
Re-deploy, browser access http://localhost:8080/todo/ve can see the effect.
Simply introduce velocity
Velocity is a java-based template engine with three types of file loading templates: 1, loading 2 from a file path, starting with the Classpath (Myvelocity01.java using this method) 3, and loading from the jar file to start contacting Velocity may encounter problems on the load template.
How to pass a variable to a template file: The template itself can define a variable, for example, a variable $this,java code is defined in TEST.VM, and a variable can be passed to a template, such as a variable in TEST.VM $name is a velocitycontext instance that passes past. Velocity also supports iterative objects, such as: We import java.util.Vector in Myvelocity01.java and code:
Copy Code code as follows:
Context.put ("name", "Test");
To
Copy Code code as follows:
Vector v = new vector ();
V.addelement ("Harry");
V.addelement ("John");
String[] names = {"Harry", "John"};
Context.put ("Names1", V);
Context.put ("Names2", names);
Change the TEST.VM content to:
Copy Code code as follows:
#foreach ($name in $names 1)
$name <br/>
#end
#foreach ($name in $names 2)
$name <br/>
#end
Velocity also supports the map container, which enables the introduction of static templates using #include ("") and the introduction of dynamic Templates #parse ("template name").
Using servlet + velocity is a small and flexible option if you don't want to write a Web site with Java MVC.
