学步园

package org.eleaf.java.guestbook.tags;

import java.util.*;
import java.text.*;
import javax.servlet.http.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;

public class NowDateTag extends TagSupport{
    private String prefix = "", language = "", country = "";
    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }
    public void setCountry(String country) {
        this.country = country;
    }
    public void setLanguage(String language) {
        this.language = language;
    }
    private String filterLanguage(String language) { //分析请求头Accept-Language
        if (language.length() >=2) {
            language = language.substring(0,2);
        }
        return language;
    }
    public int doStartTag() throws JspException {
        try {
            Date date = new Date();
            Locale locale = new Locale(filterLanguage(language), country);
            String nowDate = prefix + " " + getNowDate(date, locale) + " " + getDayOfWeek(date, locale);
            pageContext.getOut().println(nowDate);
        } catch (Exception e) {
            throw new JspException(e);
        }
        return SKIP_BODY;
    }
    private String getNowDate(Date date, Locale locale) {
        String nowDate = "";
        DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, locale);
        nowDate += df.format(date);
        return nowDate;
    }
    private String getDayOfWeek(Date date, Locale locale) {
        Calendar cal = Calendar.getInstance(locale);
        cal.setTime(date);
        int index = cal.get(Calendar.DAY_OF_WEEK);
        DateFormatSymbols symbols = new DateFormatSymbols(locale);
        String[] days = symbols.getWeekdays();
        return days[index];
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC '-//Sun Microsystems, Inc.//DTD JSP Tag Library
    1.2//EN' 'http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd'>
   
<taglib>
    <tlib-version>1.2</tlib-version>
    <jsp-version>1.2</jsp-version>
    <short-name>Html Tags</short-name>
    <tag>
        <name>nowDate</name>
        <tag-class>org.eleaf.java.guestbook.tags.NowDateTag</tag-class>
        <body-content>empty</body-content>
        <attribute>
            <name>prefix</name>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>language</name>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>country</name>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
    </tag>
</taglib>

<%@ page contentType="text/html;charset=GBK" %>
<%@ page import="java.util.*" %>
<%@ taglib prefix="htm" uri="/WEB-INF/tlds/html-tag.tld" %>
<htm:nowDate prefix="今天是" language="zh" country="cn" />
<br>
<htm:nowDate prefix="美国版本：" language="en" country="" />
<br>
<htm:nowDate prefix="英国版本：" language="en" country="uk" />
<br>
<htm:nowDate prefix="日本版本：" language="ja" country="jp" />
<br>
<htm:nowDate prefix="台湾地区版本：" language="zh" country="tw" />
<br>
<htm:nowDate prefix="法国版本：" language="fr" country="cn" />
<br>
<htm:nowDate prefix="根据浏览器确定:" language="<%=request.getHeader("Accept-language")%>" country="" />
<br>

<%
    Locale loc = new Locale("fr", "cn");
    out.println(loc.getDisplayLanguage() + ":" + loc.getDisplayCountry() + "<br>");
    loc = new Locale("fr", "fr");
    out.println(loc.getDisplayLanguage() + ":" + loc.getDisplayCountry() + "<br>");
    loc = new Locale("fr", "错误国家代码");
    out.println(loc.getDisplayLanguage() + ":" + loc.getDisplayCountry() + "<br>");
%>

结果：

今天是 2005年2月17日 星期四
美国版本： February 17, 2005 Thursday
英国版本： February 17, 2005 Thursday
日本版本： 2005/02/17 木曜日
台湾地区版本： 2005年2月17日 星期四
法国版本： 17 février 2005 jeudi
根据浏览器确定: 2005年2月17日 星期四
法文:中国
法文:法国
法文:错误国家代码