jsp 自定义标签实例
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2023-11-26 19:51:28
分三步： 一、在web-inf 下建一个名为tlds的文件夹，再建一个tld文件，如 formattime.tld，内容为： 复制代码 代码如下:
分三步：
一、在web-inf 下建一个名为tlds的文件夹，再建一个tld文件，如 formattime.tld，内容为：
<?xml version="1.0" encoding="iso-8859-1" ?>
<!doctype taglib public "-//sun microsystems, inc.//dtd jsp tag library 1.1//en"
"http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.1</jspversion>
<shortname>ntuc</shortname>
<tag>
<name>formattimeasstring</name>
<tagclass>com.ufinity.taglibtest.formattimetag</tagclass>
<bodycontent>empty</bodycontent>
<attribute>
<name>timestamp</name>
</attribute>
<attribute>
<name>format</name>
</attribute>
<attribute>
<name>showth</name>
</attribute>
<attribute>
<name>style</name>
</attribute>
</tag>
</taglib>
二、建一个class，内容为：
package com.ufinity.taglibtest;
import java.io.ioexception;
import java.text.dateformat;
import java.text.parseexception;
import java.text.simpledateformat;
import java.util.calendar;
import java.util.date;
import java.util.locale;
import javax.servlet.jsp.tagext.tagsupport;
/**
* description of the class
*
* @author wangqy
* @version 1.0
* @since 2009-8-25
*/
public class formattimetag extends tagsupport {
/**
* serialversionuid long
*/
private static final long serialversionuid = 8757501937718830491l;
private string timestamp;
private string format;
private string showth;
private string style;
public int doendtag()
{
try
{
string info = this.convertdatetime(timestamp, format, boolean.parseboolean(showth), style);
pagecontext.getout().println(info);
}
catch (ioexception e) {
}
return eval_page;
}
private string convertdatetime(string datetime, string formater, boolean showth, string casestyle) {
string timeposted = null;
simpledateformat datefm = null;
dateformat format = new simpledateformat("yyyymmddhhmmss");
date formattime = null;
try {
formattime = format.parse(datetime);
} catch (parseexception e) {
return null;
}
calendar calendar = calendar.getinstance();
calendar.settime(formattime);
if (showth) {
int day = calendar.get(calendar.day_of_month);
string daysuffix = "th";
if ((day % 10) == 1) {
daysuffix = ((day / 10) == 1) ? "th" : "st";
} else if ((day % 10) == 2) {
daysuffix = (day == 12) ? "th" : "nd";
} else if ((day % 10) == 3) {
daysuffix = (day == 13) ? "th" : "rd";
}
formater = formater.substring(0, formater.indexof(" ")) + "'"
+ daysuffix + "'"
+ formater.substring(formater.indexof(" "));
datefm = new simpledateformat(formater, locale.english);
} else {
datefm = new simpledateformat(formater, locale.english);
}
timeposted = datefm.format(formattime);
if (casestyle.equals("upper")) {
timeposted = timeposted.touppercase();
} else if (casestyle.equals("lower")) {
timeposted = timeposted.tolowercase();
}
return timeposted;
}
public void setformat(string format) {
this.format = format;
}
public void setshowth(string showth) {
this.showth = showth;
}
public void setstyle(string style) {
this.style = style;
}
public void settimestamp(string timestamp) {
this.timestamp = timestamp;
}
}
三、建个jsp页面测试下：
<%@ page language="java" pageencoding="utf-8"%>
<%@ taglib uri="web-inf/tlds/formattime.tld" prefix="tf" %>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=gb2312" />
<title>自定义标签示例</title>
</head>
<body>
<p>
转换“20090403132233”
</p>
format:dd mmmm yyyy showth:true style:upper 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style="upper"/><br/>
format:dd mmmm yyyy showth:true style:lower 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style="lower"/><br/>
format:dd mmmm yyyy showth:false style:upper 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="false" style="upper"/><br/>
format:dd mmmm yyyy showth:true style:"" 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style=""/><br/>
</body>
</html>
ok了。这里timestamp是一个给定值，如果是通过${}标签动态取的话，需要将tld文件的
<attribute>
<name>timestamp</name>
</attribute>
修改为
<attribute>
<name>timestamp</name>
<rtexprvalue>true</rtexprvalue>
</attribute>
一、在web-inf 下建一个名为tlds的文件夹，再建一个tld文件，如 formattime.tld，内容为：
复制代码 代码如下:
<?xml version="1.0" encoding="iso-8859-1" ?>
<!doctype taglib public "-//sun microsystems, inc.//dtd jsp tag library 1.1//en"
"http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.1</jspversion>
<shortname>ntuc</shortname>
<tag>
<name>formattimeasstring</name>
<tagclass>com.ufinity.taglibtest.formattimetag</tagclass>
<bodycontent>empty</bodycontent>
<attribute>
<name>timestamp</name>
</attribute>
<attribute>
<name>format</name>
</attribute>
<attribute>
<name>showth</name>
</attribute>
<attribute>
<name>style</name>
</attribute>
</tag>
</taglib>
二、建一个class，内容为：
复制代码 代码如下:
package com.ufinity.taglibtest;
import java.io.ioexception;
import java.text.dateformat;
import java.text.parseexception;
import java.text.simpledateformat;
import java.util.calendar;
import java.util.date;
import java.util.locale;
import javax.servlet.jsp.tagext.tagsupport;
/**
* description of the class
*
* @author wangqy
* @version 1.0
* @since 2009-8-25
*/
public class formattimetag extends tagsupport {
/**
* serialversionuid long
*/
private static final long serialversionuid = 8757501937718830491l;
private string timestamp;
private string format;
private string showth;
private string style;
public int doendtag()
{
try
{
string info = this.convertdatetime(timestamp, format, boolean.parseboolean(showth), style);
pagecontext.getout().println(info);
}
catch (ioexception e) {
}
return eval_page;
}
private string convertdatetime(string datetime, string formater, boolean showth, string casestyle) {
string timeposted = null;
simpledateformat datefm = null;
dateformat format = new simpledateformat("yyyymmddhhmmss");
date formattime = null;
try {
formattime = format.parse(datetime);
} catch (parseexception e) {
return null;
}
calendar calendar = calendar.getinstance();
calendar.settime(formattime);
if (showth) {
int day = calendar.get(calendar.day_of_month);
string daysuffix = "th";
if ((day % 10) == 1) {
daysuffix = ((day / 10) == 1) ? "th" : "st";
} else if ((day % 10) == 2) {
daysuffix = (day == 12) ? "th" : "nd";
} else if ((day % 10) == 3) {
daysuffix = (day == 13) ? "th" : "rd";
}
formater = formater.substring(0, formater.indexof(" ")) + "'"
+ daysuffix + "'"
+ formater.substring(formater.indexof(" "));
datefm = new simpledateformat(formater, locale.english);
} else {
datefm = new simpledateformat(formater, locale.english);
}
timeposted = datefm.format(formattime);
if (casestyle.equals("upper")) {
timeposted = timeposted.touppercase();
} else if (casestyle.equals("lower")) {
timeposted = timeposted.tolowercase();
}
return timeposted;
}
public void setformat(string format) {
this.format = format;
}
public void setshowth(string showth) {
this.showth = showth;
}
public void setstyle(string style) {
this.style = style;
}
public void settimestamp(string timestamp) {
this.timestamp = timestamp;
}
}
三、建个jsp页面测试下：
复制代码 代码如下:
<%@ page language="java" pageencoding="utf-8"%>
<%@ taglib uri="web-inf/tlds/formattime.tld" prefix="tf" %>
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=gb2312" />
<title>自定义标签示例</title>
</head>
<body>
<p>
转换“20090403132233”
</p>
format:dd mmmm yyyy showth:true style:upper 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style="upper"/><br/>
format:dd mmmm yyyy showth:true style:lower 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style="lower"/><br/>
format:dd mmmm yyyy showth:false style:upper 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="false" style="upper"/><br/>
format:dd mmmm yyyy showth:true style:"" 转换后为：<tf:formattimeasstring timestamp="20090403132233" format="dd mmmm yyyy" showth="true" style=""/><br/>
</body>
</html>
ok了。这里timestamp是一个给定值，如果是通过${}标签动态取的话，需要将tld文件的
复制代码 代码如下:
<attribute>
<name>timestamp</name>
</attribute>
修改为
复制代码 代码如下:
<attribute>
<name>timestamp</name>
<rtexprvalue>true</rtexprvalue>
</attribute>