jsp的自定义标签 控制jsp内容显示

<%@ taglib prefix="fns" uri="/WEB-INF/tlds/fns.tld" %>

<?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>2.0</jsp-version>
<short-name>bgt</short-name>
<!-- backGroundTag -->
<uri>http://www.sdyy.tag</uri>
<tag>
<name>hasUrlPerm</name>
<tag-class>com.sdyy.common.tags.HasUrlPermissionTag</tag-class>
<attribute>
<name>link</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue><!-- 是否支持恶劣表达式 -->
<type>java.lang.String</type>
<description>示例：acApplication/forMain.do</description>
</attribute>

</tag>
</taglib>

A、【判断标签】HasUrlPermissionTag标签是一个判断标签，通过该标签来决定标签包裹的内容是否显示，写法如下：

package com.sdyy.common.tags;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;

import com.sdyy.common.spring.interceptor.PermissionInterceptor;
/**
*
* @ClassName: HasUrlPermissionTag
* @Description: 根据url判断权限标签
* @author: liuyx
* @date: 2015年12月21日上午11:15:32
*/
public class HasUrlPermissionTag extends BodyTagSupport {

private String link;//  abc.do

@Override
public int doStartTag() throws JspException { // 在标签开始处出发该方法

HttpServletRequest request=(HttpServletRequest) pageContext.getRequest();
//获取session中存放的权限

//判断是否有权限访问
if (PermissionInterceptor.isOperCanAccess(request, link)) {
//允许访问标签body
return BodyTagSupport.EVAL_BODY_INCLUDE;// 返回此则执行标签body中内容，SKIP_BODY则不执行
} else {
return BodyTagSupport.SKIP_BODY;
}

}

@Override
public int doEndTag() throws JspException {
return BodyTagSupport.EVAL_BODY_INCLUDE;
}

public String getLink() {
return link;
}

public void setLink(String link) {
this.link = link;
}

}

<bgt:hasUrlPerm link="abc.do">
<div>tttttttttttttttttest</div>
</bgt:hasUrlPerm>

package com.sdyy.common.tags;

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

import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;

/*import com.sdyy.base.ac.ac_permission.model.AcPermission;*/

public class ButtonUrlTag extends BodyTagSupport {
private static final long serialVersionUID = -7811902545513255473L;

//标签属性用户名
private String user = null;
//标签属性操作url
private String url = null;
//标签属性 js方法
private String jsmethod = null;
//标签属性image 按钮图片
private String image = null;
//标签属性 alt 提示
private String alt = null;
//标签属性操作value 按钮文本
private String value  = null;

/* 标签初始方法 */
public int doStartTag() throws JspTagException{
return super.EVAL_BODY_INCLUDE;
}

/* 标签结束方法 */
public int doEndTag() throws JspTagException{
pageContext.getSession();
Boolean b = false;
List list = new ArrayList();
/*AcPermission p = new AcPermission();*/
/*JDBCHibernate jdbca = new JDBCHibernate();*/
try {
/*list = jdbca.getHaveURLByUsernameList(user);*/
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
for(int i = 0;i < list.size(); i++){
/*p = (AcPermission) list.get(i);*/
if(1==1) {//p.getUrl().trim().equals(url.trim())){
b = true;
//如果jsmethod属性不为null 则把超链接href改为调用js
if(jsmethod!=null){
url = jsmethod;
}
}
}
JspWriter out = pageContext.getOut();
if(b){
try {
//有权限 显示操作按钮
out.println("<a href='" +url+ "' class='regular'><img src='" + image + "' alt='" + alt +"' />" + value + "</a>");
} catch (IOException e) {
e.printStackTrace();
}
}

return super.SKIP_BODY;
}

/* 释放资源 */
public void release(){
super.release();
}

public String getUser() {
return user;
}

public void setUser(String user) {
this.user = user;
}

public String getUrl() {
return url;
}

public void setUrl(String url) {
this.url = url;
}

public String getImage() {
return image;
}

public void setImage(String image) {
this.image = image;
}

public String getAlt() {
return alt;
}

public void setAlt(String alt) {
this.alt = alt;
}

public String getValue() {
return value;
}

public void setValue(String value) {
this.value = value;
}

public String getJsmethod() {
return jsmethod;
}

public void setJsmethod(String jsmethod) {
this.jsmethod = jsmethod;
}
}