自定义JSP标签

1.XML配置

  <jsp-config>    <taglib>      <taglib-uri>/WEB-INF/tld/cmsTagLib</taglib-uri>      <taglib-location>/WEB-INF/tld/cmsTagLib.tld</taglib-location>    </taglib>  </jsp-config>

2.编写/WEB-INF/tld/cmsTagLib.tld

<?xml version="1.0" encoding="UTF-8"?><taglib><tlib-version>1.0</tlib-version><jsp-version>1.2</jsp-version><tag>  <name>action</name>  <tag-class>com.oemp.cmstemplate.util.CmsTemplateTag</tag-class>  <body-content>empty</body-content>  <attribute>    <name>value</name>    <required>false</required>    <rtexprvalue>true</rtexprvalue>  </attribute></tag><tag>  <name>content</name>  <tag-class>com.oemp.cmstemplate.util.CmsTemplateContentTag</tag-class>  <body-content>jsp</body-content></tag></taglib>

3.实现类

package com.oemp.cmstemplate.util;import java.lang.reflect.Method;import javax.servlet.jsp.JspException;import javax.servlet.jsp.JspTagException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.TagSupport;import com.oemp.cmstemplate.struts2.CmsTemplateAction;import com.util.tools.UtilTools;/** * 自定义标签 */public class CmsTemplateTag extends TagSupport {private static final long serialVersionUID = 1L;private String value = "";public int doStartTag() throws JspException {try {JspWriter out = pageContext.getOut();            String val=value!=null&&value.length()>2?value.substring(0,3):value;if (value.equals("date")) {out.print(UtilTools.getDate());}else if(val.equals("get")){//自定义内容String className = "com.oemp.cmstemplate.struts2.CmsTemplateAction";try {Object obj = Class.forName(className).newInstance();Method method = obj.getClass().getMethod(value);//如果有参数的方法，getMethod后面可以再加一个数组参数out.print(method.invoke(obj));} catch (IllegalAccessException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}else {CmsTemplateAction cms = new CmsTemplateAction();out.print(cms.getContent(value));}} catch (java.io.IOException e) {throw new JspTagException(e.getMessage());}return SKIP_BODY;}public String getValue() {return value;}public void setValue(String value) {this.value = value;}}

第二种标签：

package com.oemp.cmstemplate.util;import java.io.IOException;import javax.servlet.http.HttpServletRequest;import javax.servlet.jsp.JspTagException;import javax.servlet.jsp.tagext.BodyTagSupport;import com.util.tools.UtilTools;/** * 自定义内容标签 */public class CmsTemplateContentTag extends BodyTagSupport {private static final long serialVersionUID = 1L;public int doStartTag() throws JspTagException {return EVAL_BODY_BUFFERED;}public int doEndTag() throws JspTagException {String body = this.getBodyContent().getString();HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();        //页面中的自定义标签替换<cms:content> Date: $date</cms:content>body = body.replace("$date", UtilTools.getDate());try {pageContext.getOut().print(body);} catch (IOException e) {throw new JspTagException(e.getMessage());}return SKIP_BODY;}}

相关类：

package com.oemp.cmstemplate.struts2;import java.util.HashMap;import java.util.Map;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.oemp.cmstemplate.service.CmsTemplateInfoService;import com.util.tools.UtilTools;public class CmsTemplateAction {private CmsTemplateInfoService tempInfoService;     /**     * 替换标签内容     * @param value     * @return     */public String getContent(String value) {Map<String,String> param = new HashMap<String,String>();   param.put("ctlName", value);   Map<String, String> map= new HashMap<String,String>();   String content = "";   try {   ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");   tempInfoService=(CmsTemplateInfoService)ctx.getBean(CmsTemplateInfoService.class);   map = tempInfoService.getTempAction(param);   content = UtilTools.isEmpty(map.get("ctlContent"))?"":map.get("ctlContent");   } catch (Exception e) {   // TODO Auto-generated catch block   e.printStackTrace();   }       return content;} /**  * 得到会员信息  * @return  */public String getMember() {String content = "中华人民共和国";// TODO Auto-generated method stubreturn content;}}

4.JSP 引用：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@taglib uri="/WEB-INF/tld/cmsTagLib" prefix="cms"%><%String path = request.getContextPath();%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>starting page</title>  </head>   <body>    This is my JSP page. <br>    Date : <%= new java.util.Date().toString() %> <br/>    File : <input value="<%= request.getServletPath() %>" />  <br/>        ============================================================ <br/>        Date : <cms:action value="date" /><br>    File : <cms:action value="mobile_public_login" /> <br/>    Method:<cms:action value="getMember" /><br>        <hr>    <cms:content>    Date: $date<br>    File: $filename    </cms:content>      </body></html>