一，工具类，分页类和连接数据库jdbc
package com.direct.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class ConnCreate {
private static final String DRIVER="com.mysql.jdbc.Driver";
private static final String URL="jdbc:mysql://localhost:3306/countryside_buy?userUnicode=true&characterEncoding=utf-8";
private static final String USER="root";
private static final String PWD="123456";
static{
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
//创建连接对象
public Connection createConn(){
Connection conn = null;
try {
conn = DriverManager.getConnection(URL, USER, PWD);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
//关闭连接
public void closeJ(Connection conn,PreparedStatement ps,ResultSet rs) throws SQLException{
if(rs!=null) rs.close();
if(ps!=null) ps.close();
if(conn!=null) conn.close();
}
}
package com.direct.util;
import java.io.Serializable;
import java.util.ArrayList;
public class JavaBeanPage<T> implements Serializable {
/*
* javaBean 定义分页模型 泛型
*/
private int pagesize=3;//每页显示的条数
private int pageno=1;//当前页码
private int totalrecords;//总数据条数
private int totalpage;
private ArrayList<T> datalist = null;//当前页的数据
public int getPagesize() {
return pagesize;
}
public void setPagesize(int pagesize) {
this.pagesize = pagesize;
}
public int getPageno() {
return pageno;
}
public void setPageno(int pageno) {
this.pageno = pageno;
}
public int getTotalrecords() {
return totalrecords;
}
public void setTotalrecords(int totalrecords) {
this.totalrecords = totalrecords;
}
public int getTotalpage() {
return totalpage;
}
// 设置总页数 总数据/每页条数
public void setTotalpage() {
if (totalrecords%pagesize==0) {
this.totalpage = totalrecords/pagesize;
}else {
this.totalpage = totalrecords/pagesize+1;
}
}
public ArrayList<T> getDatalist() {
return datalist;
}
public void setDatalist(ArrayList<T> datalist) {
this.datalist = datalist;
}
public JavaBeanPage(int pagesize, int pageno, int totalrecords,
int totalpage, ArrayList<T> datalist) {
super();
this.pagesize = pagesize;
this.pageno = pageno;
this.totalrecords = totalrecords;
this.totalpage = totalpage;
this.datalist = datalist;
}
public JavaBeanPage() {
super();
}
}
二，dao层对数据的连接和对数据的基本操作
package com.direct.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Map;
import com.direct.entity.User;
import com.direct.util.ConnCreate;
import com.direct.util.JavaBeanPage;
public class UserJdbc {
//从数据中用sql语句分页，得到每页的显示数据集合对象
public JavaBeanPage<User> getlist(Map<String, Object> map){
JavaBeanPage<User> page = new JavaBeanPage<User>();
page.setPageno(Integer.parseInt((String) map.get("pageno"))); //设置当前页码
// page.setPagesize((Integer)map.get("pagesize")); //设置每页显示的数据数量
page.setTotalrecords(getCount());//设置总数据条数
page.setTotalpage();//设置总页数
/* ArrayList<User> datalist = page.getDatalist();
System.out.println(datalist.get(0)); */
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
PreparedStatement ps = null;
ResultSet rs =null;
// 查询起始位置 （当前页数-1）*每页显示的条数
int begin =(page.getPageno() -1)*page.getPagesize();
//查询每页显示条数
int end = page.getPagesize();
String sql = "select * from user limit "+begin+" , "+end;
ArrayList<User> list = new ArrayList<User>();//临时存放user对象，最后传入page中的集合
try {
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
User user= new User(rs.getInt("user_id"),
rs.getString("user_name"),
rs.getString("user_email"),
rs.getString("user_password"),
rs.getString("user_telphone"),
rs.getInt("user_status"),
rs.getString("user_sex"));
//System.out.println(user);
list.add(user);
}
page.setDatalist(list);
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
return page;
}
//访问数据库得到数据的总条数
public int getCount(){
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
PreparedStatement ps = null;
ResultSet rs =null;
int count=0;
String sql = "select count(user_id) as count from user";
try {
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
count= rs.getInt("count");
}
// System.out.println("总数据条数："+count);
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, null);
} catch (SQLException e) {
e.printStackTrace();
}
}
return count;
}
public ArrayList<User> qurey(String name,String pwd){
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
StringBuffer sql=new StringBuffer("select * from user where 1=1");
ArrayList<User> uList=new ArrayList<User>();
PreparedStatement ps = null;
ResultSet rs = null;
if (name!=null&&!("").equals(name)&&pwd!=null&&!("").equals(pwd)) {
sql.append(" and user_name='"+name+"'");
sql.append(" and user_password='"+pwd+"'");
try {
ps= conn.prepareStatement(sql.toString());
rs = ps.executeQuery();
while (rs.next()) {
User user= new User(rs.getInt("user_id"),
rs.getString("user_name"),
rs.getString("user_email"),
rs.getString("user_password"),
rs.getString("user_telphone"),
rs.getInt("user_status"),
rs.getString("user_sex"));
uList.add(user);
//System.out.println("list添加一个对象");
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
return uList;
}
//参数列表不同，不同的调用，应该用重载
public ArrayList<User> qurey(String name,int id){
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
StringBuffer sql=new StringBuffer("select * from user where 1=1");
ArrayList<User> uList=new ArrayList<User>();
PreparedStatement ps = null;
ResultSet rs = null;
if(name!=null&&!("").equals(name)){
sql.append(" and user_name='"+name+"'");
}else if(id!=0){
sql.append(" and user_id='"+id+"'");
}
try {
ps= conn.prepareStatement(sql.toString());
rs = ps.executeQuery();
while (rs.next()) {
User user= new User(rs.getInt("user_id"),
rs.getString("user_name"),
rs.getString("user_email"),
rs.getString("user_password"),
rs.getString("user_telphone"),
rs.getInt("user_status"),
rs.getString("user_sex"));
uList.add(user);
System.out.println("list添加一个对象");
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, rs);
} catch (SQLException e) {
e.printStackTrace();
}
}
return uList;
}
//增
public Boolean addUsers(User uent){
Boolean bool = false;
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
PreparedStatement ps = null;
String sql = "insert into user(user_name,user_email,user_password,user_telphone,user_status,user_sex) values(?,?,?,?,?,?)";
try {
ps = conn.prepareStatement(sql);
ps.setString(1, uent.getUname());
ps.setString(2, uent.getUemail());
ps.setString(3, uent.getUpwd());
ps.setString(4, uent.getUtel());
ps.setInt(5, uent.getUsatus());
ps.setString(6, uent.getUsex());
int temp = ps.executeUpdate();
if (temp>0) {
System.out.println("添加成功！！！");
bool = true;
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, null);
} catch (SQLException e) {
e.printStackTrace();
}
}
return bool;
}
// 改
public Boolean changeUser(int id,User uent){
Boolean bool = false;
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
PreparedStatement ps=null;
//update user set user_name=?,user_email=?,user_password=?,user_telphone=?,user_sex=? where name ='star'
StringBuffer sql = new StringBuffer("update user set user_name=?,user_email=?,user_password=?,user_telphone=?,user_sex=? where user_id= '"+id+"'");
try {
ps = conn.prepareStatement(sql.toString());
ps.setString(1, uent.getUname());
ps.setString(2, uent.getUemail());
ps.setString(3, uent.getUpwd());
ps.setString(4, uent.getUtel());
ps.setString(5, uent.getUsex());
int rows = ps.executeUpdate();
if(rows>0){
System.out.println("修改成功！！！");
bool=true;
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, null);
} catch (SQLException e) {
e.printStackTrace();
}
}
return bool;
}
//删
public Boolean deleteUser(int id){
Boolean bool = false;
ConnCreate connCreate = new ConnCreate();
Connection conn = connCreate.createConn();
PreparedStatement ps = null;
String sql = "delete from user where user_id='"+id+"'";
try {
ps = conn.prepareStatement(sql);
int rows = ps.executeUpdate();
if (rows>0) {
System.out.println("删除成功！！！");
bool = true;
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
connCreate.closeJ(conn, ps, null);
} catch (SQLException e) {
e.printStackTrace();
}
}
return bool;
}
/* public static void main(String[] args) {
ArrayList<User> list = new UserJdbc().qurey("小白","123456");
System.out.println(list.size());
User user = new User(1, "小蓝", "nn147552384@163.com", "435256", "13996932845", 0, "女");
new UserJdbc().addUsers(user);
System.out.println(new UserJdbc().getCount());
//new UserJdbc().getlist();
}*/
}
三，service层的接受前台数据和响应
package com.direct.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.direct.dao.UserJdbc;
import com.direct.entity.User;
import com.direct.util.JavaBeanPage;
public class UserServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");// 设置字符编码
response.setContentType("text/html;charset=utf-8");// 设置输出内容的类型及字符编码
response.setCharacterEncoding("utf-8");
/*
* 三种作用域
* request 一次请求 只能用forward转换页面
* session 一次会话 在浏览器中可以访问，关闭浏览器重开不能
* application 一直 关闭浏览器后在打开，访问得到 （一般用于网站访问人数的数据）
*/
String username = request.getParameter("username");// 获取值 表单值
String[] values = request.getParameterValues("hobby");// 获取数组 表单复选框
String hob = "";
for (int i = 0; i < values.length; i++) {
hob+=values[i]+",";
}
HttpSession session = request.getSession();
session.setAttribute("sname", "dgdfhhh");
session.setAttribute("spwd", "fugfgh");
session.setMaxInactiveInterval(10);//设置最大存在时间 单位秒
session.invalidate();//销毁
session.removeAttribute("sname");//移除存放的值
ServletContext application = this.getServletContext();
application.setAttribute("aname", "fyjhjhgjfk");
application.setAttribute("apwd", "dfjgfhdf");
/*
* 内部跳转 请求转发 forward() 一次请求 外部跳转 重定向 sendRedirect() 两次请求
*/
// request.getRequestDispatcher("MyJsp.jsp").forward(request, response);
PrintWriter out = response.getWriter();// 返回PrintWriter 输出流对象
// out.print("sdfniodg");//响应给前台
// response.sendRedirect("MyJsp.jsp");// 重定向跳转页面
String op = request.getParameter("op");
if(("page").equals(op)){
//op=page&pageno=1
String pageno = request.getParameter("pageno");//当前页码
System.out.println(pageno+"pageno");
Map< String, Object> map = new HashMap<String, Object>();
map.put("pageno", pageno);
//map.put("pagesize", 3);
UserJdbc userJdbc = new UserJdbc();
JavaBeanPage<User> pagelist = userJdbc.getlist(map);
request.setAttribute("nowdate", new Date());//存入当前时间
request.setAttribute("pagelist", pagelist);//存入request属性值
//request.getRequestDispatcher("pagelist.jsp").forward(request, response);
request.getRequestDispatcher("jstl.jsp").forward(request, response);
} else {
System.out.println("--------------else----------");
}
}
}
四，jsp页面取数据和显示的几种方式
jstl中 c 标签和 fmt 标签的简单使用。和实现真分页。以及el表达式的简单运用
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%
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 'jstl.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 cellpadding="0" cellspacing="0" width="50%" align="center">
<tr> <th>编号</th>
<th>ID</th>
<th>用户名</th>
<th>邮件</th>
<th>电话</th>
<th>密码</th>
<th>性别</th>
</tr>
<c:forEach items="${pagelist.datalist}" var="item" varStatus="status">
<tr>
<td>${status.index }</td>
<td>${item.uid }</td>
<td>${item.uname }</td>
<td>${item.uemail }</td>
<td> ${item.utel }</td>
<td>${item.upwd }</td>
<td>${item.usex }</td>
</tr>
</c:forEach>
<tr>
<td></td>
<td>当前页：${pagelist.pageno } /总页数：${pagelist.totalpage }</td>
<td><a href="UserServlet?op=page&pageno=1"> 首页</a></td>
<td><a href="UserServlet?op=page&pageno=${pagelist.pageno>1?pagelist.pageno-1:pagelist.pageno}">上一页</a></td>
<td><a href="UserServlet?op=page&pageno=${pagelist.pageno<pagelist.totalpage?pagelist.pageno+1:pagelist.totalpage}">下一页</a></td>
<td><a href="UserServlet?op=page&pageno=${pagelist.totalpage }">尾页</a></td>
</tr>
</table>
<c:set value="99" var="score"></c:set>
成绩：<c:out value="${score}"></c:out>
<c:if test="${score>80}">成绩很优秀 </c:if><br/>
<c:set value="6" var="grade" ></c:set>
<select name="grade">
<c:choose>
<c:when test="${grade==1}">
<option value="1">倔强青铜</option>
</c:when>
<c:when test="${grade==2}">
<option value="2">秩序白银</option>
</c:when>
<c:when test="${grade==3}">
<option value="3">荣耀黄金</option>
</c:when>
<c:when test="${grade==4}">
<option value="4">尊贵铂金</option>
</c:when>
<c:when test="${grade==5}">
<option value="5">永恒钻石</option>
</c:when>
<c:otherwise >
<option >王者</option>
</c:otherwise>
</c:choose>
</select>
<br/>
<c:set value="语文，数学，英语，C++，C#，JAVA，PHP" var="subject" scope="session"></c:set>
<c:forTokens items="${subject}" delims="，" begin="0" end="2" var="ke">
<c:out value="${ke}"></c:out><br/>
</c:forTokens>
<br/>
当前时间：<fmt:formatDate value="${nowdate}" pattern="yyyy年MM月dd日 HH:mm:ss"/>
<br/>
<h3>数字格式化:</h3>
<c:set var="balance" value="120000.2309" />
<p>格式化数字 (1): <fmt:formatNumber value="${balance}"
type="currency"/></p>
<p>格式化数字 (2): <fmt:formatNumber type="number"
maxIntegerDigits="3" value="${balance}" /></p>
<p>格式化数字 (3): <fmt:formatNumber type="number"
maxFractionDigits="3" value="${balance}" /></p>
<p>格式化数字 (4): <fmt:formatNumber type="number"
groupingUsed="false" value="${balance}" /></p>
<p>格式化数字 (5): <fmt:formatNumber type="percent"
maxIntegerDigits="3" value="${balance}" /></p>
<p>格式化数字 (6): <fmt:formatNumber type="percent"
minFractionDigits="10" value="${balance}" /></p>
<p>格式化数字 (7): <fmt:formatNumber type="percent"
maxIntegerDigits="3" value="${balance}" /></p>
<p>格式化数字 (8): <fmt:formatNumber type="number"
pattern="###.###E0" value="${balance}" /></p>
<p>美元 :
<fmt:setLocale value="en_US"/>
<fmt:formatNumber value="${balance}" type="currency"/></p>
<hr/>
<%--el表达式的使用：
等于：== eq
不等于：！= ne
大于等于：>= ge
小于等于：<= le
小于：< lt
大于：> gt
逻辑与： && and
逻辑或： || or
逻辑非： ! not
是否为空：empty
--%>
总条数：${requestScope.pagelist.totalrecords }<br/>
等于：${pagelist.pageno eq pagelist.pagesize }<br/>
不等于：${pagelist.pageno ne pagelist.pagesize }<br/>
</body> </html>
jstl中标签的使用，c,fmt,functions。
服务器开启后，直接访问本页面即可
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn"%>
<%
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 'jstlApply.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>
<!-- 1根据不同年龄段 判断人群类别。 少年 青年 …….. （多种方式实现）
2使用forTokens 拆分遍历数据。（blue,red,green|yellow|pink,black|white）
3获得时间：格式化输出年 月 日 时 分 秒 AM /PM
4得到一个数字 已不同的方式输出为金额格式 (美元 人民币)
-->
<c:set value="25" var="age"></c:set>
<c:out value="${age}"></c:out><br/>
<hr/>
c:choose和c:when方式：
<c:choose>
<c:when test="${age<=10}">儿童</c:when>
<c:when test="${age<=30&&age>10}">青年</c:when>
<c:when test="${age<=50&&age>30}">中年</c:when>
<c:when test="${age>50}">老年</c:when>
</c:choose><br/>
c:if方式：
<c:if test="${age<=10}">儿童</c:if>
<c:if test="${age<=30&&age>10}">青年</c:if>
<c:if test="${age<=50&&age>30}">中年</c:if>
<c:if test="${age>50}">老年</c:if><br/>
<hr/>
<c:set value="blue,red,green|yellow|pink,black|white" var="str"></c:set>
原字符串：<c:out value="${str}"></c:out><br/>
c:forTokens:
<c:forTokens items="${str}" delims="," var="color">
<c:forTokens items="${color}" delims="|" var="co">
${co}
</c:forTokens>
</c:forTokens>
<hr/>
<c:set value="<%=new Date() %>" var="nowdate"></c:set><br/>
<fmt:formatDate value="${nowdate}" pattern="yyyy年MM月dd日 HH:mm:ss a" var="date"/>
fmt:formatDate：<c:out value="${date}"></c:out><br/>
<c:set value="3568" var="num"></c:set>
fmt:formatNumber：
<fmt:formatNumber type="currency" value="${num}" ></fmt:formatNumber><br/>
<fmt:formatNumber currencySymbol="$" value="${num}"></fmt:formatNumber><br/>
<fmt:formatNumber currencyCode="$" value="${num}"></fmt:formatNumber><br/>
<!-- jstl函数：使用
5 判断字符串A中是否有存在子串B （忽略大小写/不忽略大小写）;
6 集合中装有多个字符串，遍历 输出以指定字符结尾的 字符串;
7集合中装有多个字符串，输出不同字符串中指定字符出现的位置。
8将多个字符串 拼接为一个字符串。
9截取返回 字符串 指定范围、 之前、 之后的内容。
10字符串的替换操作。
-->
<% String str1 = "javascripet";
String str2 = "vAsc";
ArrayList liststr = new ArrayList();
liststr.add("bluejstl");
liststr.add("redjstld");
liststr.add("yelllowjstl");
liststr.add("blackjstla");
liststr.add("bluejstl");
request.setAttribute("liststr",liststr);
%>
jstl:function<br/>
${fn:contains(str1,str2) }<br/>
${fn:containsIgnoreCase(str1,str2) }<br/>
endsWith:
<c:forEach items="${liststr}" var="strl" varStatus="status">
${status.index}
${strl}
${fn:endsWith(strl, "jstl")} <%="," %><br/>
</c:forEach><br/>
indexOf: <c:forEach items="${liststr}" var="strof">
${strof}
${fn:indexOf(strof, 'j')}
<%="," %>
</c:forEach><br/>
<hr/>
<c:set var="string1" value="I am from google"/>
<c:set var="string2" value="${fn:replace(string1, 'google', 'runoob')}" />
<p>replace替换后的字符串 : ${string2}</p>
<hr/>
<c:set var="string1" value="www runoob com"/>
<c:set var="string2" value="${fn:split(string1, ' ')}" />
<%
String[] arr = {"This","is","array","string"};
request.setAttribute("arr",arr);
%>
<c:set value="${arr}" var="array"></c:set>
arr使用join连接： ${fn:join(array,'-') }
<c:set var="string3" value="${fn:join(string2, '-')}" /><!-- string2是字符串数组 -->
<p>字符串为 : ${string3}</p>
<c:set var="string4" value="This is first String."/>
<c:set var="string5" value="${fn:substring(string4, 5, 15)}" />
<p>生成的子字符串为 : ${string5}</p>
<c:set var="string6" value="${fn:substringAfter(string4, 'is')}" />
<p>After生成的子字符串 : ${string6}</p>
<c:set var="string7" value="${fn:substringBefore(string4, 'first')}" />
<p>Before生成的子字符串 : ${string7}</p>
</body>
</html>
五，web.xml中的配置，以及使用配置文件实现初始化数据
<?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">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>UserServlet</servlet-name>
<servlet-class>com.direct.servlet.UserServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UserServlet</servlet-name>
<url-pattern>/UserServlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>config_jsp</servlet-name>
<jsp-file>/config.jsp</jsp-file>
<init-param>
<param-name>configFile</param-name>
<param-value>confi.txt配置文件的信息</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>config_jsp</servlet-name>
<url-pattern>/conf.jsp</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
六，web.xml 中初始化的数据在发布服务器后可直接访问取数据
config.jsp
访问 http://localhost:8082/webProject/conf.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
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 'config.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>
配置文件名：<%=config.getInitParameter("configFile") %>
</body>
</html>