本文实例讲述了jsp通过自定义标签库实现数据列表显示的方法。分享给大家供大家参考，具体如下：
1. 定义标签库类 UserListTag.java
package com.yanek.cms.tag;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.BodyTagSupport;
import com.yanek.cms.vo.UserInfo;
public class UserListTag extends BodyTagSupport {
private String name;// 一个属性名
private Iterator it;// 要迭代的对象
private int cateid; // 用户类别id
@Override
public int doEndTag() throws JspException {
try {
if (bodyContent != null) {
bodyContent.writeOut(bodyContent.getEnclosingWriter());
}
} catch (IOException e) {
e.printStackTrace();
}
return EVAL_PAGE;
}
@Override
public int doStartTag() throws JspException {
//这里根据用户类型,构造不同的列表数据,实现可以根据数据库获取
ListUserInfo> users = new ArrayListUserInfo>();
if (cateid == 1) {
users.add(new UserInfo("张三", 20, "Zhangsan@163.com"));
users.add(new UserInfo("李四", 30, "Lisi@sina.com"));
} else {
users.add(new UserInfo("王五", 33, "Wangwu@qq.com"));
users.add(new UserInfo("赵六", 33, "zhaoliu@qq.com"));
}
it = users.iterator();
if (it == null) {
return SKIP_BODY;
} else {
return continueNext();
}
}
private int continueNext() {
if (it.hasNext()) {
pageContext.setAttribute(name, it.next(), pageContext.PAGE_SCOPE);
return EVAL_BODY_TAG;
} else {
return SKIP_BODY;
}
}
@Override
public int doAfterBody() {
return continueNext();
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getCateid() {
return cateid;
}
public void setCateid(int cateid) {
this.cateid = cateid;
}
}
2. 在WEB-INF目录下 新建标签库描述文件my_cms_tag.tld：
my_cms_tag.tld
?xml version="1.0" encoding="UTF-8"?>
!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN" "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
taglib>
tlibversion>1.0/tlibversion>
jspversion>1.0/jspversion>
shortname>cms/shortname>
uri>http://www.58tech.cn/mystruts/tags-cms/uri>
!-- userListTag start -->
tag>
name>userListTag/name>
tag-class>com.yanek.cms.tag.UserListTag/tag-class>
body-content>jsp/body-content>
variable>
!--name-given>user_info/name-given>-->
name-from-attribute>name/name-from-attribute>
variable-class>com.yanek.cms.vo.UserInfo/variable-class>
declare>true/declare>
scope>NESTED/scope>
/variable>
attribute>
name>name/name>
required>true/required>
/attribute>
attribute>
name>cateid/name>
required>true/required>
/attribute>
/tag>
!-- userListTag end -->
/taglib>
3. web.xml配置
?xml version="1.0" encoding="UTF-8"?> web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> welcome-file-list> welcome-file>index.jsp/welcome-file> /welcome-file-list> taglib> taglib-uri>/tags/my-cms/taglib-uri> taglib-location>/WEB-INF/my_cms_tag.tld/taglib-location> /taglib> /web-app>
4. jsp调用
%@ page language="java" import="java.util.*,com.yanek.cms.vo.*" pageEncoding="UTF-8"%>
%@ taglib uri="/tags/my-cms" prefix="myTag" %>
%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
html>
head>
base href="%=basePath%>">
title>My JSP 'test.jsp' starting page/title>
meta http-equiv="pragma" content="no-cache">
meta http-equiv="cache-control" content="no-cache">
meta http-equiv="expires" content="0">
meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
meta http-equiv="description" content="This is my page">
!--
link rel="stylesheet" type="text/css" href="styles.css">
-->
/head>
body>
table width='500px' border='1' align='center'>
tr>
td width='20%'>UserName/td>
td width='20%'>Age/td>
td>Email/td>
/tr>
myTag:userListTag name="user_info1" cateid="1">
tr>
td>%=user_info1.getUserName() %>/td>
td>%=user_info1.getAge() %>/td>
td>%=user_info1.getEmail() %>
/td>
/tr>
/myTag:userListTag>
/table>
hr>
table width='500px' border='1' align='center'>
tr>
td width='20%'>UserName/td>
td width='20%'>Age/td>
td>Email/td>
/tr>
myTag:userListTag name="user_info2" cateid="2">
tr>
td>%=user_info2.getUserName() %>/td>
td>%=user_info2.getAge() %>/td>
td>%=user_info2.getEmail() %>
/td>
/tr>
/myTag:userListTag>
/table>
/body>
/html>
实体类定义
package com.yanek.cms.vo;
public class UserInfo {
private int age;
private String userName;
private String email;
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public UserInfo(String userName,int age, String email) {
super();
this.age = age;
this.userName = userName;
this.email = email;
}
public UserInfo() {
}
}
运行效果如下图 （URL输入：http://127.0.0.1:8080/TestCMS/page/userlist.jsp）
完整实例代码代码点击此处本站下载。
希望本文所述对大家Android程序设计有所帮助。
