java中结合struts2自定义标签的使用
一、建立一个继承于SimpleTagSupport类实现它的doTag方法
1 package com.xiangshang.tag; 2 3 import java.io.IOException; 4 import java.util.List; 5 6 import javax.servlet.jsp.JspException; 7 import javax.servlet.jsp.PageContext; 8 import javax.servlet.jsp.tagext.SimpleTagSupport; 9 10 import com.opensymphony.xwork2.ActionContext; 11 import com.opensymphony.xwork2.util.ValueStack; 12 13 public class FunctionTag extends SimpleTagSupport { 14 15 private String value; 16 17 private String name; 18 19 public String getName() { 20 return name; 21 } 22 23 public void setName(String name) { 24 this.name = name; 25 } 26 27 public String getValue() { 28 return value; 29 } 30 31 public void setValue(String value) { 32 this.value = value; 33 } 34 35 @SuppressWarnings("unchecked") 36 @Override 37 public void doTag() throws JspException, IOException { 38 StringBuilder sb = new StringBuilder(); 39 PageContext pageContext = (PageContext) this.getJspContext(); 40 List<String> functions = (List<String>) pageContext.getSession() 41 .getAttribute("functions"); 42 ValueStack vs = ActionContext.getContext().getValueStack(); 43 String str = (String) vs.findValue(name); 44 for (String s : functions) { 45 if (s.equals(str)) { 46 sb.append("<a href=\"javascript:alert(‘有权限‘)\">") 47 .append(value).append("</a>"); 48 break; 49 } 50 } 51 if (sb.length()==0) { 52 sb.append("<a href=\"javascript:alert(‘没权限!!‘)\">") 53 .append(value).append("</a>"); 54 } 55 pageContext.getOut().print(sb); 56 } 57 }
为了测试方便本人在建立了session监听器来存储function:
1 package com.xiangshang.listener; 2 3 import java.util.ArrayList; 4 import java.util.List; 5 6 import javax.servlet.ServletContext; 7 import javax.servlet.ServletContextEvent; 8 import javax.servlet.ServletContextListener; 9 import javax.servlet.http.HttpSessionEvent; 10 import javax.servlet.http.HttpSessionListener; 11 12 import org.springframework.web.context.WebApplicationContext; 13 import org.springframework.web.context.support.WebApplicationContextUtils; 14 15 import com.xiangshang.service.UserService; 16 17 public class MySessionListener implements HttpSessionListener{ 18 @Override 19 public void sessionCreated(HttpSessionEvent hse) { 20 System.out.println("Zhangqy Session Created"); 21 List<String> functions= new ArrayList<String>(); 22 functions.add("添加人信息"); 23 functions.add("删除人信息"); 24 functions.add("查看人信息"); 25 functions.add("修改人信息"); 26 hse.getSession().setAttribute("functions",functions); 27 } 28 29 @Override 30 public void sessionDestroyed(HttpSessionEvent hse) { 31 } 32 33 34 }
二、在WEB-INF下创建tld 文件:xiangshang.tld
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd" > 3 <taglib> 4 <tlib-version>1.0</tlib-version> 5 <jsp-version>2.0</jsp-version> 6 <short-name>x</short-name> 7 <uri>/xiangshang-tags</uri> 8 <display-name>xiangshang tags</display-name> 9 <tag> 10 <name>a</name> 11 <tag-class>com.xiangshang.tag.FunctionTag</tag-class> 12 <body-content>empty</body-content> 13 <attribute> 14 <name>name</name> 15 <required>true</required> 16 <rtexprvalue>true</rtexprvalue> 17 <type>java.lang.String</type> 18 </attribute> 19 <attribute> 20 <name>value</name> 21 <required>true</required> 22 <rtexprvalue>true</rtexprvalue> 23 <type>java.lang.String</type> 24 </attribute> 25 </tag> 26 </taglib>
三、在jsp界面中首先倒入自定义的标签库 :
<%@ taglib uri="/xiangshang-tags" prefix="x" %>
四、接下来就是开始使用自定义标签了:
<x:a name="添加人信息" value="添加人信息"/>