jsp之自定义标签基本包括三部分:.java-->.tld-->页面调用
现在来看看自定义标签的日历制作:
一.TagCalendar.jsp
Codeimport java.io.IOException;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
import javax.servlet.jsp.JspWriter;
public class TagCalendar extends TagSupport {
private static final long serialVersionUID = -7677534442361565504L;
@Override
public int doStartTag() throws JspException {
JspWriter out = pageContext.getOut();
StringBuffer sCalendar = new StringBuffer();
GregorianCalendar gc = new GregorianCalendar();
int today = gc.get(Calendar.DAY_OF_MONTH);
int month = gc.get(Calendar.MONTH);
int year = gc.get(Calendar.YEAR);
String days[] = new String[42];
for (int i = 0; i < 42; i++) {
days[i] = "";
}
Calendar cal = Calendar.getInstance();
cal.clear();
cal.set(Calendar.MONTH, month); // 设置当月
cal.set(Calendar.YEAR, year); // 设置当年
cal.setFirstDayOfWeek(Calendar.SUNDAY);// 设置星期天开始
cal.set(Calendar.DAY_OF_MONTH, 1); // 设置1号
int firstIndex = cal.get(Calendar.DAY_OF_WEEK) - 1; // 取得当月1号所在的星期数
int maxIndex = cal.getActualMaximum(Calendar.DAY_OF_MONTH); // 取得当月的最大天数
for (int i = 0; i < maxIndex; i++) {
days[firstIndex + i] = String.valueOf(i + 1);
}
try {
sCalendar.append("<table border='0' width='168' height='81'>");
sCalendar.append("<tr><td colspan='7' align='center'>"+year + "年" + (month + 1) + "月" + today+"日</td></tr>");
sCalendar.append("<tr><th width='25' height='16'><font color='red'>日</font></th>");
sCalendar.append("<th width='25' height='16'>一</th><th width='25' height='16'>二</th>");
sCalendar.append("<th width='25' height='16'>三</th><th width='25' height='16'>四</th>");
sCalendar.append("<th width='25' height='16'>五</th><th width='25' height='16'><font color='red'>六</font></th></tr>");
for(int i=0;i<6;i++){
sCalendar.append("<tr>");
for(int j=i*7;j<(i+1)*7;j++){
sCalendar.append("<td width='15%' height='16' valign='middle' align='center'>");
if((j-firstIndex+1)==today){
sCalendar.append("<font color='red'>"+days[j]+"</font>");
}else{
sCalendar.append(days[j]);
}
sCalendar.append("</td>");
}
sCalendar.append("</tr>");
}
sCalendar.append("</table>");
out.print(sCalendar.toString());
} catch (IOException e) {
e.printStackTrace();
}
return TagSupport.SKIP_BODY;
}
}
自定义标签类继承TagSupport,由于不需要方法体,此处只需要重写doStartTag()方法,拼接字符串好累啊.呵呵
二.tld文件
Code<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "/WEB-INF/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
<tlib-version>2.0</tlib-version>
<jsp-version>2.5</jsp-version>
<short-name>jr</short-name>
<tag>
<name>calendar</name>
<tag-class>
net.trilbyframework.kernel.jrich.taglibs.TagCalendar
</tag-class>
<body-content>empty</body-content>
</tag>
</taglib>
由于没有方法体,则<body-content>必须设为empty.
三.页面的调用
Code<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="jr" uri="JRich.tld.tld"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>日历</title>
</head>
<body>
<jr:calendar/>
</body>
</html>
ok,运行一下,可以看出效果来了,呵呵.
当然,这个只是一个当前月份(服务器时间,而不是客户端的时间)的小小的展示,后面加入其他功能和事件,及css样式表.
浙公网安备 33010602011771号