创建自定义标签,struts2

1，建立自己的标签库tld文件

topdt-tags.tld：

 

 

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd">

<display-name>topdt</display-name>

<tlib-version>1.0</tlib-version>

<short-name>td</short-name>

<tag>

<name>page</name>

<tag-class>com.topdt.frame.web.tags.PageTag</tag-class>

<body-content>JSP</body-content>

<attribute>

<name>template</name>

<required>true</required>

</attribute>

</tag>

<tag>

<name>ss</name>

<tag-class>com.topdt.frame.web.tags.SubStringTag</tag-class>

<body-content>JSP</body-content>

<attribute>

<name>start</name>//这里添加标配的属性

<required>false</required>

<rtexprvalue>false</rtexprvalue>

</attribute>

<attribute>

<name>end</name>

<required>false</required>

<rtexprvalue>false</rtexprvalue>

</attribute>

</tag>

</taglib>

 

2：web.xml文件中加入：

 

 

<jsp-config>

<taglib>

<taglib-uri>/topdt</taglib-uri>

<taglib-location>

/WEB-INF/tlds/topdt-tags.tld

</taglib-location>

</taglib>

</jsp-config>

 

 

3：创建class：

 

 

package com.topdt.frame.web.tags;

import javax.servlet.jsp.JspException;

import javax.servlet.jsp.JspWriter;

import javax.servlet.jsp.tagext.BodyTagSupport;

public class SubStringTag extends BodyTagSupport {

private static final long serialVersionUID = 1L;

private int start = 0;//这里对应tld中的属性

private int end = 0;

public int getEnd() {

return end;

}

public void setEnd(int end) {

this.end = end;

}

public int getStart() {

return start;

}

public void setStart(int start) {

this.start = start;

}

public int doEndTag() throws JspException {

try {

JspWriter out = pageContext.getOut();

String b = this.getBodyContent().getString();

b = uToS(b);

if (end < b.length()) {

b = b.substring(start, end)+ "..";

}

out.write(b);

} catch (Exception e) {

throw new JspException(e);

}

return SKIP_BODY; // 不包含主体内容

}

private String uToS(String s) throws Exception {

String[] s3 = s.split(";");

String s1 = "";

if (s3.length > 1) {

for (int i = 0; i < s3.length; i++) {

String[] s2 = s3[i].split("&#");

if (s2.length > 1) {

int v = Integer.parseInt(s2[1], 10);

s1 = s1 + s2[0] + (char) v;

} else {

s1 = s1 + s3[i];

}

}

return s1;

} else {

return s;

}

}

}