jsp自定义标签跟着走_jsp中tag 标签联动-优快云博客

本文链接：https://blog.youkuaiyun.com/tgystc/article/details/1861815

第一步:写类,继承自TagSupport ,实现一些方法,如int doStartTag() 等,代码如下:
package wtc.jspTag;

import java.io.IOException;
import java.util.List;

import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* <p>
* @author wujy <br>
* @date 2007-11-1 <br>
* <p>
* 备注:<br>
* 1. <br>
* 2. <br>
* 3. <br>
* </p>
*
*/
public class PurviewTag extends TagSupport {
private static final long serialVersionUID = 9090686619873665127L;
private final Logger logger = LoggerFactory.getLogger(this.getClass());
private final String defaultFunctionName = "purviewChecker";
private String functionName = null;

@SuppressWarnings("unchecked")
public int doStartTag() {
  try {
   JspWriter out = pageContext.getOut();
   if(functionName == null || functionName.equals("")){
    functionName = defaultFunctionName;
   }
   out.println("<script type=/"text/javascript/">");
   out.print("var ");
   out.print(functionName);
   out.println(" = function(){");
   out.print("var purviews = ['add']");
   out.println(" ");
   out.println("return {");
   out.println("check : function(toCheck){");
   out.println("for(var index=0; index<purviews.length; index++) {");
   out.println("if (purviews[index] == toCheck){");
   out.println("return true;");
   out.println("}");
   out.println("}");
   out.println("return false;");
   out.println("}");
   out.println("};");
   out.println("}();");
   out.println("</script>");
  } catch(IOException ioe) {
   logger.debug("Error in Tag out.print.", ioe);
  }
  return(SKIP_BODY);
}

/**
* @return functionName
*/
public String getFunctionName() {
  return functionName;
}
/**
* @param functionName 要设置的 functionName
*/
public void setFunctionName(String functionName) {
  this.functionName = functionName;
}

}

第二步:写tld,放到与web.xml同目录,内容如下:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
"http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
    <tlib-version>1.0</tlib-version>
    <jsp-version>1.2</jsp-version>
    <short-name>p</short-name>
    <uri>http://www.youkuaiyun.com/tld/purview</uri>
    <tag>
       <name>purview</name>
       <tag-class>net.gmcchr.privilege.PurviewTag</tag-class>
       <body-content>empty</body-content>
       <attribute>
           <name>functionName</name>
           <required>false</required>
       </attribute>
    </tag>
</taglib>

第三步:调用,如下:(注意有背景色的那些)

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ taglib uri="/WEB-INF/purview.tld" prefix="p" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>My JSP 'tryPurviewTag.jsp' starting page</title>

<p:purview functionName="purviewChecker"/>

</head>

<body>
    <button οnclick="alert(purviewChecker.check('add'));">allow add?</button>
    <button οnclick="alert(purviewChecker.check('del'));">allow del?</button>
    <button οnclick="alert(purviewChecker.check('mod'));">allow mod?</button>
</body>
</html>

ok简单的就是这样.