我的数据库中有两个表（文件详细信息和文件状态）。
我使用以下代码在filedetails表中插入值。
在filestatus表中，我有3列
filenumber,
fdepartment,
status(either in or out).
在我的
status.jsp页面中，我给出了3个下拉列表，其中2个下拉列表从filenumber表中获取department和filedetails，1个获得状态（IN或OUT）。如果状态为OUT，则仅将值插入
filestatus表中，但如果是OUT，则将值插入filestatus中，并更新与department对应的filenumber。问题是
filenumber，如果我使用以下代码插入filenumber，那么我将如何更新文件编号？还有其他方法吗？
file.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert File Page</title>
<style>
header {
background-color:teal;
color:white;
text-align:center;
padding:30px;
}
section {
width:350px;
float:left;
padding:150px;
}
footer {
background-color:black;
color:white;
clear:both;
text-align:center;
padding:5px;
}
</style>
</head>
<body style="background-color:lightsteelblue;">
<%
String userName = null;
String sessionID = null;
Cookie[] cookies = request.getCookies();
if(cookies !=null){
for(Cookie cookie : cookies){
if(cookie.getName().equals("user")) userName = cookie.getValue();
}
}
%>
<header>
<h3>Hi <%=userName %></h3>
</header>
<a href="create.jsp"><font color="black">back</font></a>
<form action=" LogoutServlet" method="post">
<input type="submit" value="Logout" >
</form>
<section>
<form action="FileServlet" method="post">
<h3>Insert File Details</h3>
<table border="1">
<tbody>
<tr>
<td>File Name :</td>
<td><input type="text" name="filename" value="" size="50" /></td>
</tr>
<tr>
<td>File Type</td>
<td><input type="text" name="type" value="" size="50" /> </td>
</tr>
<tr>
<td>Place of Origin(company) :</td>
<td><input type="text" name="company" value="" size="50" /></td>
</tr>
<tr>
<td>HeadOffice :</td>
<td><input type="text" name="HO" value="" size="50" /> </td>
</tr>
<tr>
<td>File Location :</td>
<td><input type="text" name="department" value="" size="50" /> </td>
</tr>
<tr>
<td>Subject :</td>
<td><input type="text" name="subject" value="" size="50" /></td>
</tr>
<tr>
<td>File Number :</td>
<td><input type="text" name="fileno" value="" size="50" /></td>
</tr>
</tbody>
</table>
<input type="reset" value="Clear" name="Clear" />
<input type="submit" value="Submit" name="Submit" />
</form>
</section>
<footer>
Copyright 2008 NSIC. All right reserved.
</footer>
</body>
</html>
fileServlet.java
package bean;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class FileServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Cookie[] cookies = request.getCookies();
if(cookies != null){
for(Cookie cookie : cookies){
if(cookie.getName().equals("JSESSIONID")){
System.out.println("JSESSIONID="+cookie.getValue());
break;
}
}
}
HttpSession session = request.getSession(false);
System.out.println("User="+session.getAttribute("user"));
if(session!=null && session.getAttribute("user") != null){
String user=(String)session.getAttribute("user");
boolean status=false;
try{
String fname=request.getParameter("name");
String type=request.getParameter("type");
String company=request.getParameter("department");
String headoffice=request.getParameter("HO");
String location=request.getParameter("department");
String subject=request.getParameter("subject");
String fno=company+"/"+headoffice+"/"+location+"/"+type+"/"+fname;
Connection con=ConnectionProvider.getCon();
String sql="insert into files(fileno,fname,ftype,subject,company,headoffice,fdepartment) values (?,?,?,?,?,?)";
PreparedStatement pstmt =con.prepareStatement(sql);
pstmt.setString(1,fno);
pstmt.setString(2,fname);
pstmt.setString(3,type);
pstmt.setString(4,subject);
pstmt.setString(5,company);
pstmt.setString(6,headoffice);
pstmt.setString(7,location);
int rs=pstmt.executeUpdate();
if(rs>0){status=true;}
}catch(Exception e){System.out.println(e);}
if(status){
PrintWriter out= response.getWriter();
out.println("Values have been inserted"+user);
response.sendRedirect("create1.jsp");
}
else
{
PrintWriter out= response.getWriter();
out.println("failed");
response.sendRedirect("create1.jsp");
}
}else{
RequestDispatcher rd = getServletContext().getRequestDispatcher("/index.html");
PrintWriter out= response.getWriter();
out.println("<font color=red>Either user name or password is wrong.</font>");
rd.include(request, response);
}
}
}
有create.jsp，它提供了用于选择filedetails.jsp或status.jsp的链接
status.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@ page import ="java.sql.*" %>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>File Status Page</title>
<style>
header {
background-color:teal;
color:white;
text-align:center;
padding:30px;
}
section {
width:350px;
float:left;
padding:150px;
}
footer {
background-color:black;
color:white;
clear:both;
text-align:center;
padding:5px;
}
</style>
</head>
<body style="background-color:lightsteelblue;">
<%
String userName = null;
String sessionID = null;
Cookie[] cookies = request.getCookies();
if(cookies !=null){
for(Cookie cookie : cookies){
if(cookie.getName().equals("user")) userName = cookie.getValue();
}
}
%>
<header>
<h3>Hi <%=userName %></h3>
</header>
<a href="create.jsp"><font color="black">back</font></a>
<form action=" LogoutServlet" method="post">
<input type="submit" value="Logout" >
</form>
<section>
<h3>Change Status</h3>
<form action="statusServlet" method="post">
<select name="files">
<%
try{
String sql="select * from files";
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/login",
"root", "root");
Statement st = con.createStatement();
ResultSet rs=st.executeQuery(sql);
while(rs.next()){
%>
<option value="<%=rs.getInt("fileno")%>"><%=rs.getString("fname")%></option>
<%}
rs.close();
st.close();
con.close();
}catch(Exception e){
e.printStackTrace();
}
%>
</select>
<select name="departments">
<%
try{
String sql="select * from department";
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/login",
"root", "root");
Statement st = con.createStatement();
ResultSet rs=st.executeQuery(sql);
while(rs.next()){
%>
<option value="<%=rs.getInt("departmentid")%>"><%=rs.getString("departmentname")%></option>
<%}
rs.close();
st.close();
con.close();
}catch(Exception e){
e.printStackTrace();
}
%>
</select>
<select name="input">
<option>IN</option>
<option>OUT</option>
</select>
<input type="submit" value="submit" name="submit" />
</form>
</section>
<footer>
Copyright 2008 NSIC. All right reserved.
</footer>
</body>
</html>
我尚未创建statusServlet.java
最佳答案
我将部门分为以下两个部分。
1）产生文件的部门
2）文件的当前位置。
我将使用文件来源部门生成filenumber，并将分别更新当前位置（最初，当前位置将与来源部门相同）。
如果有人有比这更有效的方法，那么我也将接受。