1、自定义方法标签
引入方式示例:
<%@ taglib prefix="fns" uri="/WEB-INF/tlds/fns.tld" %>
写法示例:
<?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>JSTL 1.1 functions library</description> <display-name>JSTL functions sys</display-name> <tlib-version>1.1</tlib-version> <short-name>fns</short-name> <uri>http://java.sun.com/jsp/jstl/functionss</uri> <!-- DictUtils --> <function> <description>获取字典对象列表</description> <name>getDictList</name> <function-class>com.sdyy.base.sys.utils.DictUtils</function-class> <function-signature>java.util.List getDictList(java.lang.String)</function-signature> <example>${fns:getDictList(typeCode)}</example> </function> <function> <description>获取字典对象列表</description> <name>getDictListJson</name> <function-class>com.sdyy.base.sys.utils.DictUtils</function-class> <function-signature>java.lang.String getDictListJson(java.lang.String)</function-signature> <example>${fns:getDictListJson(typeCode)}</example> </function> <function> <description>对象变json</description> <name>toJSONString</name> <function-class>com.alibaba.fastjson.JSON</function-class> <function-signature>java.lang.String toJSONString(java.lang.Object)</function-signature> </function> </taglib>
function-class就是该方法的实体所在类路径,
function-signature就是该方法的方法名,值得一提的是,这个方法必须是个static方法。
example就是使用方法示例
2、通过jsp自定义标签(虽然里面是jsp的写法,但是扩展名要命名为.tag 2017-03-27 17:04 感谢评论区一楼指正)
<%@ taglib prefix="sys" tagdir="/WEB-INF/tags/sys" %>
如此 tags目录下的sys目录下的jsp(虽然里面是jsp的写法,但是扩展名要命名为.tag 2017-03-27 17:04 感谢评论区一楼指正)形式的tag就会自动被加载,标签jsp写法示例:
<%@ tag language="java" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <%@ taglib prefix="fns" uri="/WEB-INF/tlds/fns.tld" %> <%@ attribute name="typeCode" type="java.lang.String" required="true" description="字典code"%> <%@ attribute name="defaultValue" type="java.lang.String" description="默认选中"%> <%@ attribute name="style" type="java.lang.String" description="默认选中"%> <%@ attribute name="cls" type="java.lang.String" description="默认选中"%> <%@ attribute name="name" type="java.lang.String" description="默认选中"%> <select style="${style}" class="${cls}" name="${name}" id="${name}" > <option value="" >请选择... </option> <c:if test="${not empty typeCode}"> <c:forEach items="${fns:getDictList(typeCode)}" var='dict'> <option value='${dict.VALUE}' ${defaultValue==dict.VALUE?'selected':''}>${dict.TEXT}</option> </c:forEach> </c:if> </select>
如此,jsp名就是标签名,例如这个jsp叫 select.tag(扩展名要命名为.tag 2017-03-27 17:04 感谢评论区一楼指正),那么它的用法就是
<sys:select cls="formselect" name="MODULE_TYPE" typeCode="HOME_MODULE_TYPE" defaultValue="${record.MODULE_TYPE }" />
3、通过tld文件和java代码自定义元素标签
引入方式和1相同,写法示例如下:
<?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>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;// acApplication/forMain.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; } }
在JSP中的使用方式:
<bgt:hasUrlPerm link="abc.do"> <div>tttttttttttttttttest</div> </bgt:hasUrlPerm>
B、【控件标签】,这种标签直接返回一个控件,不过是通过java代码生成的控件内容,写法示例:
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; } }