自定义标签

public class ParseViewIPTag extends TagSupport{

	@Override
	public int doStartTag() throws JspException {
		HttpServletRequest request = (HttpServletRequest) this.pageContext.getRequest();
		
		JspWriter out = this.pageContext.getOut();
		
		String ip = request.getRemoteAddr();
		try {
			out.print(ip);
		} catch (IOException e) {
			throw new RuntimeException(e);
		}
		return super.doStartTag();
	}

}

 

<?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">
    
    <description>A tag library exercising SimpleTag handlers.</description>
    <tlib-version>1.0</tlib-version>
    <short-name>c</short-name>
    <uri>http://www.com.cn</uri>
    
    
    <tag>
        <name>viewIP</name>
		<tag-class>com.util.ParseViewIPTag</tag-class>
		<body-content>empty</body-content>
    </tag>
    
</taglib>

<%@taglib uri="http://www.com.cn" prefix="c" %>

您的ip是：<c:viewIP/>