Custom Struts2 simple tag

Last Update:2013-12-09 Source: Internet

Author: User

Tags dateformat

Developer on Alibaba Coud: Build your first app with APIs, SDKs, and tutorials on the Alibaba Cloud. Read more ＞

Take the tag for obtaining the current time as an example to develop a custom tag bin: currentTime. The procedure is as follows:

1. First define a tag processing class.

[Java]
Package org. binbin. tag;

Import java. io. IOException;
Import java. text. DateFormat;
Import java. text. SimpleDateFormat;
Import java. util. Date;

Import javax. servlet. jsp. JspException;
Import javax. servlet. jsp. JspWriter;
Import javax. servlet. jsp. tagext. TagSupport;

/**
* Custom tags
* @ Author binbin (cn.binbin@qq.com)
* @ Date 2013-3-28
*/
Public class TimeTag extends TagSupport
{
Private static final long serialVersionUID = 6918846280074418825L;

@ Override
Public int doStartTag () throws JspException
{
JspWriter out = this. pageContext. getOut ();

// Define the time output format
DateFormat df = new SimpleDateFormat ("yyyy/MM/dd HH: mm: ss ");
// Obtain the specified format string for the current time
String str = df. format (new Date ());

Try
{
// Output the current time string to the page
Out. print (str );
} Catch (IOException e)
{
// If an exception occurs, the current program cannot handle it. Therefore, a runtime exception is thrown again.
Throw new RuntimeException (e );
}
Return super. doStartTag ();
}
}

Package org. binbin. tag;

Import java. io. IOException;
Import java. text. DateFormat;
Import java. text. SimpleDateFormat;
Import java. util. Date;

Import javax. servlet. jsp. JspException;
Import javax. servlet. jsp. JspWriter;
Import javax. servlet. jsp. tagext. TagSupport;

/**
* Custom tags
* @ Author binbin (cn.binbin@qq.com)
* @ Date 2013-3-28
*/
Public class TimeTag extends TagSupport
{
Private static final long serialVersionUID = 6918846280074418825L;

@ Override
Public int doStartTag () throws JspException
{
JspWriter out = this. pageContext. getOut ();

// Define the time output format
DateFormat df = new SimpleDateFormat ("yyyy/MM/dd HH: mm: ss ");
// Obtain the specified format string for the current time
String str = df. format (new Date ());

Try
{
// Output the current time string to the page
Out. print (str );
} Catch (IOException e)
{
// If an exception occurs, the current program cannot handle it. Therefore, a runtime exception is thrown again.
Throw new RuntimeException (e );
}
Return super. doStartTag ();
}
}
2. Then add a tag library definition file bin. tld under the WEB-INF directory

[Html]
<? Xml version = "1.0" encoding = "UTF-8"?>
<Taglib xmlns = "http://java.sun.com/xml/ns/j2ee"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance"
Xsi: schemaLocation = "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
Version = "2.0">
<Tlib-version> 1.0 </tlib-version>
<Short-name> bin </short-name>
<Uri>/bin-tags </uri>

<Tag>
<Name> currentTime </name>
<Tag-class> org. binbin. tag. TimeTag </tag-class>
<Body-content> empty </body-content>
</Tag>
</Taglib>

<? Xml version = "1.0" encoding = "UTF-8"?>
<Taglib xmlns = "http://java.sun.com/xml/ns/j2ee"
Xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance"
Xsi: schemaLocation = "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
Version = "2.0">
<Tlib-version> 1.0 </tlib-version>
<Short-name> bin </short-name>
<Uri>/bin-tags </uri>

<Tag>
<Name> currentTime </name>
<Tag-class> org. binbin. tag. TimeTag </tag-class>
<Body-content> empty </body-content>
</Tag>
</Taglib>
3. Use the tag on the jsp page

[Html]
<% @ Page language = "java" import = "java. util. *" pageEncoding = "UTF-8" %>
<! -- Import the corresponding tag Library first -->
<% @ Taglib uri = "/bin-tags" prefix = "bin" %>
<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN">
<Html>
<Head>
<Title> My JSP '1. jsp 'starting page </title>
</Head>
<Body>
Current System Time: <bin: currentTime/>
</Body>
</Html>

<% @ Page language = "java" import = "java. util. *" pageEncoding = "UTF-8" %>
<! -- Import the corresponding tag Library first -->
<% @ Taglib uri = "/bin-tags" prefix = "bin" %>
<! Doctype html public "-// W3C // dtd html 4.01 Transitional // EN">
<Html>
<Head>
<Title> My JSP '1. jsp 'starting page </title>
</Head>
<Body>
Current System Time: <bin: currentTime/>
</Body>
</Html>

Iv. Running Effect

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

Sales Support

1 on 1 presale consultation

Chat Contact Sales
After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

Open a Ticket
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

Learn More