JSP自定义标签实例（二）

来源：互联网发布：成都旅游知乎编辑：程序博客网时间：2024/05/22 03:40

1、自定义标签处理类

import java.util.Calendar;
import java.util.Date;

import org.apache.shiro.SecurityUtils;

import com.cxdai.common.Dictionary;
import com.cxdai.portal.util.CharacterEncoder;
import com.cxdai.security.ShiroUser;

/**
* <p>
* Description:自定义el表达式<br />
* </p>
*
* @title ELTag.java
* @author qiongbiao.zhang
* @version 0.1 2014年6月17日
*/
public class ELTag {

public static String encode(String input) {
return CharacterEncoder.encodeURL(input, "UTF-8");
}

public static String decode(String input) {
return CharacterEncoder.decodeURL(input, "UTF-8");
}

public static Date currDate() {
return new Date();
}

public static int year(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.YEAR);
}

public static int month(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.MONTH) + 1;
}

public static int day(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
return cal.get(Calendar.DAY_OF_MONTH);
}

public static int lastday(int year, int month) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
cal.set(Calendar.MONTH, month - 1);
return cal.getActualMaximum(Calendar.DAY_OF_MONTH);
}

public static String minDisplay(String str, int length) {
if (str == null) {
return null;
}
StringBuilder sb = new StringBuilder(length);
int l = 0;
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
sb.append(ch);
// 判断是否数字，字母，特殊字符

if (isChinese(ch)) {
l += 2;
} else {
l += 1;
}

if (l >= length) {
break;
}
}
sb.append(l >= length ? ".." : "");
return sb.toString();
}

public static boolean isChinese(char a) {
int v = a;
return (v >= 19968 && v <= 171941);
}
}

2、自定义标签文件

<?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>myel</short-name>

<function>
<name>encode</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>java.lang.String encode(java.lang.String)</function-signature>
</function>

<function>
<name>decode</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>java.lang.String decode(java.lang.String)</function-signature>
</function>

<function>
<name>currDate</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>java.util.Date currDate()</function-signature>
</function>

<function>
<name>year</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>int year(java.util.Date)</function-signature>
</function>

<function>
<name>month</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>int month(java.util.Date)</function-signature>
</function>

<function>
<name>day</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>int day(java.util.Date)</function-signature>
</function>

<function>
<name>lastday</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>int lastday(int, int)</function-signature>
</function>

<function>
<name>minDisplay</name>
<function-class>com.cxdai.common.tag.ELTag</function-class>
<function-signature>java.lang.String minDisplay(java.lang.String, int)</function-signature>
</function>
</taglib>

3、引用自定义标签

<%-- 引用自定义标签 --%>
<%@ taglib prefix="myel" uri="/WEB-INF/ELTag.tld"%>

0 0