当我尝试使用登录 jsp 登录时，它不会检查 mysql 数据库。有什么建议吗？
我的登录Jsp ------------->
JSP
<table border="0" cellpadding="0" cellspacing="0" width=0% style="font-size: 8pt;">
<%if (session.getAttribute("userName")==null) {%>
<form method="post" action="/web/login.do">
<input type="hidden" name="option" value="login">
<tr>
<td>Login:</td>
<td><input name="u_id" type="text" id="u_id" size="20"></td>
</tr>
<tr>
<td>Password:</td>
<td><input name="u_pw" type="password" id="u_pw" size="20">
</td>
</tr>
<tr>
<td></td>
<td>
<a href="/web/index.jsp">Home</a> |
<a href="/web/register.jsp">Register</a> |
<input type="submit" value="Log In">
</td>
</tr>
</form>
<%}
else {
String username=session.getAttribute("username").toString();%>
<tr><td>Login: <b><%=userName%></b></td></tr>
<tr><td>
<a href="/web/index.jsp">Home</a> |
<a href="/web/cart/cart.jsp">Cart</a> |
<% if (session.getAttribute("login").toString() {%>
<a href="/web/index.jsp">Admin Portal</a>
<% }
|
<a href="/web/log.do?option=logout">Logout</a>
</td></tr>
<%}%>
</table>
</div>
我的 WEB XML ----------------------->
<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app 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-app_2_4.xsd"
version="2.4">
<servlet>
<servlet-name>LoginLogout</servlet-name>
<servlet-class>LoginLogoutServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginLogout</servlet-name>
<url-pattern>/login.do</url-pattern>
</servlet-mapping>
</web-app>
My Context XML -------------->
Context docBase="web" path="/web" workDir="work\Catalina\localhost\web"
Resource name="jdbc/myDB" type="javax.sql.DataSource" driverClassName="com.mysql.jdbc.Driver" password="" maxIdle="2" maxWait="5000" username="root" url="jdbc:mysql://localhost:3306/mydb?autoReconnect=true" maxActive="4"/
</Context>
My LoginLogout Servlet --------------------->
Java
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class LoginLogoutServlet extends HttpServlet {
/**
*This method handles the request passed in from the interface using POST method.
*/
public void doPost(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException {
login(req,res);
}
/**
*This method handles the request passed in from the interface using GET method.
*/
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException {
doPost(req,res);
}
/**
*This method handles the login and logout of User.
*/
public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
ArrayList ex = new ArrayList();
String option = request.getParameter("option");
String uid = null;
String pw = null;
if(option.equalsIgnoreCase("login")){
uid = request.getParameter("u_id");
pw = request.getParameter("u_pw");
UserDAO user = null;
ArrayList userDB = null;
try {
user = new UserDAO();
userDB = user.retrieve();
}catch(Exception e){
ex.add(e);
}
boolean ufound = false;
HttpSession session = request.getSession();
if(ex.size()==0 && !uid.equals("") && !pw.equals("") ){
//checks for staff in the database
for(int i = 0; i < userDB.size(); i++){
User s = (User)userDB.get(i);
String login = s.getUserName();
String password = s.getPassword();
if((uid.trim().equalsIgnoreCase(login)) && (pw.trim().equalsIgnoreCase(password))){
ufound = true;
session.setAttribute("userName",uid);
}
}
/*//checks for User in the database
for(int i = 0; i < userDB.size(); i++){
User c = (User)userDB.get(i);
String email = c.getEmailAddr();
String password = c.getPasswd();
if((uid.equalsIgnoreCase(email)) && (pw.equalsIgnoreCase(password))){
ufound = true;
session.setAttribute("userName",uid);
session.setAttribute("login","customer");
session.setAttribute("customerObj",c);
//assign shopping cart to customer
session.setAttribute("ShoppingCart", new ArrayList());
//checks which page did the customer login from
if(request.getRequestURI().equals("main.html")){
//display main page
//RequestDispatcher rd = request.getRequestDispatcher("main.html");
}else{
//RequestDispatcher rd = request.getRequestDispatcher("shoppingcart.html");
}
}
}*/
}else{
ex.add(new Exception("Please complete all fields!"));
}
if(!ufound){
ex.add(new Exception("No such User found!"));
request.setAttribute("userName","notFound");
request.setAttribute("login","notFound");
}if(ufound){
session.setAttribute("login","User");
}
try {
user.close();
}catch(Exception e){
ex.add(e);
}
}else if(option.equalsIgnoreCase("logout")){
HttpSession session = request.getSession();
String login=(String) session.getAttribute("login");
if(login.equals("User")){
session.removeAttribute("userName");
//request.setAttribute("Remove","removedStaff");
}else if(login.equals("customer")){
session.removeAttribute("userName");
session.removeAttribute("cart");
//request.setAttribute("Remove","removedCust");
}
session.invalidate();
}
//assign request attributes for jsp output
request.setAttribute("option",option);
request.setAttribute("exceptions",ex);
RequestDispatcher view=null;
response.sendRedirect("/web");
out.close();
}
}
用户 DAO。
import java.sql.*;
import javax.sql.DataSource;
import javax.naming.*;
import java.util.*;
/**
*This class allows eStoreServlet to communicate with the database, myDB, through connection pooling.
*This class handles the CRUD operations of the Users entity.
*/
public class UserDAO{
private DataSource ds;
private Connection con;
/**
*Constructor gets a connection from connection pool.
*/
public UserDAO() throws Exception{
try {
Context ctx = new InitialContext();
if(ctx == null )
throw new Exception("Can't create initial context");
if(ds == null)
ds = (DataSource) ctx.lookup(eSpaceStatic.daoDS_name);
con = ds.getConnection();
} catch (NamingException e){
e.printStackTrace();
throw new Exception(e+": User"+eSpaceStatic.daoEM_cp);
}
}
/**
*Method to add a User to the database.
*@param c This is the User object.
*@return Returns an int, if -1, means User is not added to the database. Otherwise, the id of the User will be returned.
*/
public int add(User c) throws Exception{
int result = 0;
try{
PreparedStatement stmt = con.prepareStatement("insert into User(name, username, password) values(?,?,?)");
stmt.setString(1, c.getName());
stmt.setString(2, c.getUserName());
stmt.setString(3, c.getPassword());
int rownum = stmt.executeUpdate();
if(rownum == 0){
result = -1;
}else{
ResultSet rs = stmt.getGeneratedKeys();
if(rs.next()){
result = rs.getInt(1);
}
}
stmt.close();
}catch(SQLException se){
throw new SQLException(se+": Item"+eSpaceStatic.daoEM_add);
}
return result;
}
/**
*Method to retrieve all User from the database.
*@return Returns an arraylist which contains all the User objects.
*/
public ArrayList retrieve() throws Exception {
ArrayList cl = null;
try{
cl = new ArrayList();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from User");
if(rs!=null){
while(rs.next()){
User c = new User();
c.setUserId(rs.getInt("userId"));
c.setName(rs.getString("name"));
c.setUsername(rs.getString("username"));
c.setPassword(rs.getString("password"));
cl.add(c);
}
}
st.close();
}
catch(SQLException se){
System.out.println(se+": User"+eSpaceStatic.daoEM_rtr);
}
return cl;
}
/**
*Method to retrieve a User from the database.
*@param userId This is the User Id.
*@return Returns a User object.
*/
public User retrieve(int userId) throws Exception {
User ret = null;
try{
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from User where userId = "+userId);
if(rs!=null){
while(rs.next()){
User c = new User();
c.setUserId(rs.getInt("userId"));
c.setName(rs.getString("name"));
c.setUsername(rs.getString("username"));
c.setPassword(rs.getString("password"));
}
}
st.close();
rs.close();
}
catch(SQLException se){
throw new Exception(se+": "+eSpaceStatic.daoEM_cp);
}
return ret;
}
/**
*Method to update a User in the database.
*@param c This is the User object.
*@param userId This is the User id.
*@return Returns a boolean. If true, User is updated. If false, User is not updated.
*/
public boolean update(User c, int userId) throws Exception {
boolean updated = false;
try{
PreparedStatement pstmt = con.prepareStatement("update User set (name = ?, username = ?, password = ?) where userId = ?");
pstmt.setString(1, c.getName());
pstmt.setString(2, c.getUserName());
pstmt.setString(3, c.getPassword());
pstmt.setInt(4, userId);
int rownum = pstmt.executeUpdate();
updated = rownum!=0;
pstmt.close();
}catch(SQLException se){
System.out.println(se+": User"+eSpaceStatic.daoEM_rtr);
}
return updated;
}
/**
*Method to delete a User in the database.
*@param userId This is the User Id.
*@return Returns a boolean. If true, User is deleted. If false, User is not deleted.
*/
public boolean delete(int userId) throws Exception {
boolean deleted=false;
try {
PreparedStatement ps=con.prepareStatement("delete from User where userId= ?");
ps.setInt(1,userId);
ps.executeUpdate();
deleted=true;
}
catch (SQLException se) {
System.out.println(se+": User"+eSpaceStatic.daoEM_del);
}
return deleted;
}
/**
*Method to close connection.
*/
public void close() throws SQLException{
con.close();
}
}
eSpaceStatic类
public class eSpaceStatic {
public static String daoDS_name="java:comp/env/jdbc/myDB";
public static String daoEM_cp="Could not look up connection pool.";
public static String daoEM_rtr=" could not be retrieved.";
public static String daoEM_add=" could not be added.";
public static String daoEM_del=" could not be deleted.";
public static String daoEM_cnf=" could not be found.";
}
最佳答案
编辑:我应该从一开始就问这个:
When i try to login using my login jsp it doesn't check with mysql database
你怎么知道你的代码“没有检查mysql数据库”
Any advice?
是的。
- 将登录和注销分离到两个 servlet 中。它将使您的代码更易于理解和测试
- 不要将所有用户读入 ArrayList (UserDAO.retrieve())，而是向 UserDAO 添加一个方法，该方法获取登录名和密码并根据数据库检查它们。这样，如果您无法登录，您将确切地知道在哪里寻找问题
- 不要以纯文本形式存储密码。只是不要这样做。
- 在 JSP 中使用 JSTL。 action="/web/login.do"可以替换为 .您的上下文的名称可能会更改，JSTL 会处理这个问题。
关于java - 无法使用JSP和TOMCAT 7连接MYSQL数据库，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5336709/