jsp怎么监控到数据库的新数据插入？

count(*)查询数据库表中的条数，存到session对象里。刷新页面的时候判断是否改变。改变了d出提示框。

要不刷新的话就要用到AJAX，用JS里settimeout来隔几秒执行下AJAX。在后台判断数量。

这种方法并不是很常用,只是页面的相关 *** 作，代码太多,所以中间省略了部分<%

Object userUID=session.getAttribute("USERID")

String uid=""

if(userUID!=null)

{

uid=(String)userUID

}

else

{ response.sendRedirect("../Public/loseSession.jsp")}

try

{

String today=DateUtils.getInstance().getToday()

String userIP=request.getRemoteAddr()

String sql=""

String getPage=request.getParameter("toPage")

sql=cu.exchange(request.getParameter("sql"))if (sql==null||sql.equals("")){

String getDepId=""

String getPoliticalPosition=""

String getTechnicalPosition=""

String getPoliticalLevel=""

String getTechnicalLevel=""

String getDegreeCode=""

String getGrade=""

String getLongevity=""String getAllowance=""

long depId=0

long degreeCode=0

long politicalPosition=0

long technicalPosition=0

long politicalLevel=0

long technicalLevel=0

long grade=0

long longevity=0

long allowance=0

String[] postID=null

String post=""

String userID=""

String userName=""

String address=""

getDepId=request.getParameter("depId")

depId=Long.parseLong(getDepId.trim())getDegreeCode=request.getParameter("degreeCode")

if (getDegreeCode!=null) {

degreeCode=Long.parseLong(getDegreeCode.trim())

}

getPoliticalPosition=request.getParameter("politicalPosition")

if (getPoliticalPosition!=null) {

politicalPosition=Long.parseLong(getPoliticalPosition.trim())

}

post=request.getParameter("post")

if(post!=null&&post.trim().equals("1"))

postID=request.getParameterValues("dyourlocation")

getTechnicalPosition=request.getParameter("technicalPosition")if (getTechnicalPosition!=null) {

technicalPosition=Long.parseLong(getTechnicalPosition.trim())

}

getPoliticalLevel=request.getParameter("politicalLevel")if (getPoliticalLevel!=null) {politicalLevel=Long.parseLong(getPoliticalLevel.trim())

}getTechnicalLevel=request.getParameter("technicalLevel")if (getTechnicalLevel!=null) {

technicalLevel=Long.parseLong(getTechnicalLevel.trim())

}getGrade=request.getParameter("grade")if (getGrade!=null) {

grade=Long.parseLong(getGrade.trim())

}getLongevity=request.getParameter("longevity")if (getLongevity!=null) {

longevity=Long.parseLong(getLongevity.trim())

}getAllowance=request.getParameter("allowance")

if (getAllowance!=null) {

allowance=Long.parseLong(getAllowance.trim())

}

userID=ParamUtils.getParameter(request,"userID")//用户代码

userName=ParamUtils.getParameter(request,"userName")

//用户名称

address=ParamUtils.getParameter(request,"address")

//得到要转入的页面sql="select org_user.* from org_user,org_detail where org_user.user_id=org_detail.user_id"

if (depId!=0)

{

sql=sql+" and org_user.department_id="+depId+""

}if (userID!=null&&userID!=""){

sql=sql+" and org_user.user_id='"+userID+"'"

}

if (userName!=null&&userName!="")

{

sql=sql+" and org_user.name like '%"+userName+"%'"

}if (address!=null&&address!="")

{

sql=sql+" and org_user.address like '%"+address+"%'"

}

if(post!=null&&!post.trim().equals("0"))

{

sql=sql+" and org_detail.post in ("

for(int i=0i<postID.lengthi++)

{

sql=sql+postID[i]

if(i!=(postID.length-1))

sql=sql+","

}

sql=sql+")"

}

if (degreeCode!=0)

{

sql=sql+" and org_detail.degree="+degreeCode+""

}

if (politicalPosition!=0)

{

sql=sql+" and org_detail.politicalPosition="+politicalPosition+""

}

if (technicalPosition!=0)

{

sql=sql+" and org_detail.technicalPosition="+technicalPosition+""

}

if (technicalPosition!=0)

{

sql=sql+" and org_detail.politicalLevel="+politicalLevel+""

}

if (grade!=0)

{

sql=sql+" and org_detail.grade="+grade+""

}

if (longevity!=0)

{

sql=sql+" and org_detail.longevity="+longevity+""

}

if(getAllowance!=null)

{

if (allowance==0||allowance==1)

{

sql=sql+" and org_detail.allowance="+allowance+""

}

}

}

User[] userList =null

userList=ur.complexSearch(sql)

log.addLog(1,1,1,uid,userIP,uid+"于("+today+")查询员工")int cnt=userList.length//总记录数

int pageSize=10//每页显示记录数

int curPage=1//当前页

int cntPage//总页数

int m=1if (cnt>0)

{

if (cnt%pageSize==0)

cntPage=cnt/pageSize

else

cntPage=cnt/pageSize+1

}

else

cntPage=0if (getPage==null)

{

getPage="1"

curPage=1

}

else

curPage=Integer.parseInt(getPage.trim())

%><form name="thisform" action="userSearchDel.jsp" method="post">

<table bgColor="#FFFFFF" border="1" borderColorDark="#ffffff" borderColorLight="#c0c0c0" cellSpacing="0" width="95%" cellpadding="4">

<tr height="25" align="center" bgcolor="#959595">

<td>　</td>

<td><font color="#FFFFFF">姓名</font></td>

<td><font color="#FFFFFF">性别</font></td>

<td><font color="#FFFFFF">所在部门</font></td>

<td><font color="#FFFFFF">办公地址</font></td>

<td><font color="#FFFFFF">联系电话</font></td>

</tr>

<%

int u=1

for(int i=0i<cnti++)

{

//显示记录的起始位置

int j=(curPage-1)*pageSize

//显示记录的末位置

int k=curPage*pageSize

//只显示page_size条数据

if(m>j&&m<=k)

{

String userId=userList[i].getUserID()

String gender=userList[i].getGender()

String name=userList[i].getName()

String tel=userList[i].getTel()

String useAddress=userList[i].getAddress()

long dep_id=userList[i].getDepID()

String dname=dep.getName(userList[i].getDepID())

if(tel==null||tel.equals("null"))

tel=""

if(useAddress==null||useAddress.equals("null"))

useAddress=""

//判断没一行该输出的颜色

if((u%2)==0)

{

out.println("<tr bgcolor=#D7D7D7 onMouseOver=this.style.backgroundColor='#fcd4d7'onMouseOut=if(selectedItem!=this.id){this.style.backgroundColor='#D7D7D7'}>")

}

else

{

out.println("<tr onMouseOver=this.style.backgroundColor='#fcd4d7'onMouseOut=if(selectedItem!=this.id){this.style.backgroundColor='#FFFFFF'}>")

}

u++

%>

<td align=center><input type="checkbox" name="checkbox" id="CHK_+<%=userId%>" value="<%=userId%>"></td>

<td align=center>

<%

long departmentID=ur.getDepID(uid)

if(up.haveRight(uid,"USER_COMPLEXQUERY")==true)

{

%>

<a href="userAnalyze.jsp?userId=<%=userId%>&dep_id=<%=dep_id%>&toPage=<%=curPage%>"><font color="#330099">

<%

}

else if(up.haveRight(uid,"DEPARTMENT_PLATFORM")==true&&dep_id==departmentID)

{

%>

<a href="userAnalyze.jsp?userId=<%=userId%>&dep_id=<%=dep_id%>&toPage=<%=curPage%>"><font color="#330099">

<%

}

%>

<%=name%></font></a></td>

<%

if(gender.trim().equals("0"))

out.println("<td align=center>男</td>")

else

out.println("<td align=center>女</td>")

%>

<td align=center><a href="depintro.jsp?id=<%=dep_id%>&toPage=<%=curPage%>"><font color="#330099"><%=dname%></font></a></td>

<td align=center><%=useAddress%></td>

<td align=center><%=tel%></td>

</tr>

<%

}//end ifm++

}//end for

%>

<input type=hidden name="sql" value="<%=sql%>">

<input type=hidden name="page" value="<%=curPage%>">

</table>

</form>

<form name=pageform action="searchAction.jsp" method="post">

<table border="0" width="95%">

<tr>

<td align="center">第<%=curPage%>页/共<%=cntPage%>页</td>

<td align="left">

<img name="firstpage" src="../Image/btn_firstpage.gif" style="cursor:hand" onclick="pageClick(1)" <%=curPage>1?" ":"disabled"%>>

<img name="prepage" src="../Image/btn_prepage.gif" style="cursor:hand" onclick="pageClick(<%=curPage-1%>)" <%=curPage>1?" ":"disabled"%>>

<img name="nextpage" src="../Image/btn_nextpage.gif" style="cursor:hand" onclick="pageClick(<%=curPage+1%>)" <%=curPage<cntPage?" ":"disabled"%>>

<img name="lastpage" src="../Image/btn_lastpage.gif" style="cursor:hand" onclick="pageClick(<%=cntPage%>)" <%=curPage<cntPage?" ":"disabled"%>>

</td>

<td align=left width=55%>

到第<input type="text" name="goPage" size="4">页

<img border="0" src="../Image/icon_search.gif" style="cursor:hand" onclick="aPage()">

</td>

</tr><tr>

<td colspan="3" valign="middle" width="23%" align="right">

<%

if(up.haveRight(uid,"USER_MANAGE")==true)

{

%>

<img border="0" src="../Image/btn_delete.gif" style="cursor:hand" onclick="delUser()">

<%}%>

<img border="0" src="../Image/btn_return.gif" style="cursor:hand" onclick="back()">

</td>

<input type=hidden name="sql" value="<%=sql%>">

<input type=hidden name="toPage">

</td>

</tr>

</table>

</form>

<br>

<br>

</td>

</tr>

</table>

</td>

</tr>

</table>

<%

}//end else

}//end try

catch(Exception e)

{

out.println(e.getMessage())

}

%>

</td>

</tr>

</table>

<%@ page contentType="text/htmlcharset=gb2312" import="java.sql.*"%>

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/htmlcharset=utf-8" />

<title>登录网站</title>

</head>

<body>

<center>

<h1>用户登录系统</h1>

<hr>

<br>

<br>

<%

// 接收用户提交的内容

String ming = request.getParameter("zhh")

String mima = request.getParameter("mm1")

// 定义变量，如果用户是合法用户，则将此标记变为true

boolean flag = false

%>

<%

// 定义数据库 *** 作的常量、对象

// 数据库驱动程序

String DBDRIVER = "com.microsoft.jdbc.sqlserver.SQLServerDriver"

// 数据库连接字符串

String DBURL = "jdbc:microsoft:sqlserver://localhost:1433DatabaseName=jspdb"

// 数据库用户名

String DBUSER = "sa"

// 数据库连接密码

String DBPWD = "280271"

// 声明一个数据库连接对象

Connection conn = null

// 声明一个数据库 *** 作对象

PreparedStatement pstmt = null

// 声明一个结果集对象

ResultSet rs = null

// 声明一个SQL变量，用于保存SQL语句

String sql = null

%>

<%

// 进行数据库 *** 作

try

{

// 编写SQL语句

sql = "SELECT name FROM users WHERE name=? and password=?"

// 加载驱动程序

Class.forName(DBDRIVER)

// 连接数据库

conn = DriverManager.getConnection(DBURL,DBUSER,DBPWD)

// 实例化数据库 *** 作对象

pstmt = conn.prepareStatement(sql)

// 设置pstmt的内容

pstmt.setString(1,ming)

pstmt.setString(2,mima)

// 查询记录

rs = pstmt.executeQuery()

// 判断是否有记录

if(rs.next())

{

// 如果有记录，则执行此段代码

// 用户是合法的，可以登陆

flag = true

session.setAttribute("name",ming)

}

// 依次关闭

rs.close()

pstmt.close()

conn.close()

}

catch(Exception e)

{}

%>

<%

// 判断用户名及密码

if(flag)

{

// 合法用户

%>

<jsp:forward page="zhuye.jsp"/>

<%

}

else

{

// 非法用户

%>

<jsp:forward page="denglushibai.jsp"/>

<%

}

%>

</center>

</body>

</html>

---