例如自定义属性serial，
<input id="button1" type="button" value="购买" onclick="return Button1_onclick(this.serial-1)" serial="1" />
当然也可以通过css的style属性设置样式
<input type="text" id="t1" value="" style="width:100px;height:100px"/>
然后通过js来控制function textControl(){ document.getElementById("t1").style.width="100%"; document.getElementById("t1").style.height="100%";}
最后就是自定义标签库TLD，当然就可以自定义属性了；
下面就简单那解释如何自定义标签库TLD（一个标签对应一个java类，还需要在web.xml文件中配置）
下面是自定义标签库TLD的xml格式文件test.tld内容：
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE taglib
PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
"http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
<!--定义标签版本库-->
<tlib-version>1.0.1</tlib-version>
<!--定义jsp版本库-->
<jsp-version>1.2</jsp-version>
<short-name>testOne</short-name>
<uri>http://www.johnit.com.cn/tags-test</uri>
<display-name>testOne</display-name>
<description>user defination tag</description>
<validator>
<!--校验器类-->
<validator-class>
com.johnit.common.web.util.JstlTLV
</validator-class>
<init-param>
<param-name>expressionAttributes</param-name>
<param-value>
loadInfo
</param-value>
<description>
user defination tag.
</description>
</init-param>
</validator>
<tag>
<!--tag的名字-->
<name>loadInfoPopedom</name>
<tag-class>com.johnit.common.web.util.LoadInfoPopedomTag</tag-class>
<body-content>empty</body-content>
<!--关于body-content 有三个值可选;empty：标签体必须为空;jsp：标签由其他jsp元素组成比如标签中含有<%=attributeName%>的jsp元素,那么此时body-content的值就是实际attributeName传入的值;tagdependent:有标签解释不带jsp转换-->
<description>
loadInfoPopedom
</description>
<attribute><!---这里表示的是这个tag的一个参数-->
<name>id</name><!--这个参数的名字-->
<required>false</required><!--是否是必填选项-->
<rtexprvalue>false</rtexprvalue><!--这个参数的值是否可以写入，换句话说 就是这个参数是否可以动态赋值-->
</attribute>
<attribute>
<name>name</name>
<required>true</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>value</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>width</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>height</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>class</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>style</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>validate</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>size</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>options</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
</tag>
<tag>
<name>input</name>
<tag-class>com.johnit.common.web.util.LimitTag</tag-class>
<body-content>empty</body-content>
<description>
user role limit
</description>
<attribute>
<name>id</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>name</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>value</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>width</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>height</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>class</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>style</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>type</name>
<required>true</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>size</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>roles</name>
<required>true</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>onclick</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>disabled</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
<attribute>
<name>showType</name>
<required>false</required>
<rtexprvalue>false</rtexprvalue>
</attribute>
</tag>
<tag>
// 这里可以增加其他的标签
</tag>
</taglib>
接着针对每一个标签tag，写一个对应的java类，以上面com.johnit.common.web.util.LimitTag标签为例子，这java是继承BodyTagSupport（也可以继承TagSupport，其中BodyTagSupport是TagSupport的子类，但是如果继承TagSupport 而且要覆盖doEndTag()方法 ）
package com.johnit.common.web.util;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;
import org.apache.taglibs.standard.tag.common.core.NullAttributeException;
import org.apache.taglibs.standard.tag.el.core.ExpressionUtil;
public class LimitTag extends BodyTagSupport {
private static final long serialVersionUID = 3337803917881831206L;
//显示方式:0 无、1 隐藏、2 不可用
static final String SHOW_NONE="0";
static final String SHOW_HIDDEN="1";
static final String SHOW_DISABLED="2";
public LimitTag() {
init();
}
private void init() {
}
public void release() {
super.release();
init();
}
public int doStartTag() throws JspException {
//业务方法
return super.doStartTag();
}
/**
* 这里就添加业务方法
*/
protected String id;
protected String name;
protected String width;
protected String height;
protected String clazz;
protected String style;
protected String type;
protected String value;
protected String size;
private String onclick;
private String disabled;
private String roles;
private String showType;
public String getShowType() {
return showType;
}
public void setShowType(String showType) {
this.showType = showType;
}
public String getRoles() {
return roles;
}
public void setRoles(String roles) {
this.roles = roles;
}
public void setId(String id) {
this.id = id;
}
public void setSize(String size) {
this.size = size;
}
public void setType(String type) {
this.type = type;
}
public void setValue(String value) {
this.value = value;
}
public String getDisabled() {
return disabled;
}
public void setDisabled(String disabled) {
this.disabled = disabled;
}
public String getOnclick() {
return onclick;
}
public void setOnclick(String onclick) {
this.onclick = onclick;
}
public String getSize() {
return size;
}
public String getType() {
return type;
}
public String getValue() {
return value;
}
public String getClazz() {
return clazz;
}
public void setClazz(String clazz) {
this.clazz = clazz;
}
public String getHeight() {
return height;
}
public void setHeight(String height) {
this.height = height;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getStyle() {
return style;
}
public void setStyle(String style) {
this.style = style;
}
public String getWidth() {
return width;
}
public void setWidth(String width) {
this.width = width;
}
public String getId() {
return id;
}
/*******************************************************************************************************************
* 根据validate添加引号 <p> 行为描述: 状态转变: 定义的算法: 操作系统/硬件依赖: 允许的实现变化: 安全约束: </p>
*
* @param
* @return
* @throws
* @see
* @since %I%
*/
protected static String addQuotation(String str) {
int counter = 0;
StringBuffer sb = new StringBuffer(str.length());
sb.append('\'');
for (int i = 0; i < str.length(); i++) {
boolean findQuate = false;
if (str.charAt(i) == '[') {
counter++;
} else if (str.charAt(i) == ']') {
counter--;
} else if (str.charAt(i) == ',' && counter == 0) {
findQuate = true;
}
if (findQuate) {
sb.append('\'').append(str.charAt(i)).append('\'');
} else {
sb.append(str.charAt(i));
}
}
sb.append('\'');
return sb.toString();
}
/*******************************************************************************************************************
* 获取${xxx}的值 <p> 行为描述: 状态转变: 定义的算法: 操作系统/硬件依赖: 允许的实现变化: 安全约束: </p>
*
* @param
* @return
* @throws
* @see
* @since %I%
*/
protected Object getExp(String express) throws JspException {
if (express == null) {
return "";
} else if (!express.startsWith("${")) {
return express;
}
try {
return ExpressionUtil.evalNotNull("out", "value", express, java.lang.Object.class, this, pageContext);
} catch (NullAttributeException e) {
return null;
} catch (JspException e) {
throw e;
}
}
protected String getStrExp(String express) throws JspException {
return (String) getExp(express);
}
protected static String escape(String text) {
if (text == null) return "";
StringBuffer sb = new StringBuffer();
for (int i = 0; i < text.length(); i++) {
char c = text.charAt(i);
if (c == '&') {
sb.append("&");
continue;
}
if (c == '<') {
sb.append("<");
continue;
}
if (c == '>') {
sb.append(">");
continue;
}
if (c == '"') {
sb.append(""");
continue;
}
if (c == '\'') {
sb.append("'");
} else {
sb.append(c);
}
}
return sb.toString();
}
}
最后在web.xml中的<web-app>需要添加
<taglib>
<taglib-uri>http://www.johnit.com.cn/tags-test</taglib-uri>
<taglib-location>/WEB-INF/test.tld</taglib-location>
</taglib>