我正在使用Java Servlets开发Web应用程序。我正在尝试实现登录，注销和注册功能，但我对如何使一切工作有点困惑。以下是登录页面的代码：
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* and open the template in the editor.
*/
package hw5package;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author Tyler
*/
public class Login extends HttpServlet {
/**
* Processes requests for both HTTP
* <code>GET</code> and
* <code>POST</code> methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@cci-ora02.uncc.edu:1521:class";
String username = "teverha4";
String password = "qwe123";
out.println("<html>");
out.println("<head>");
out.println("<title>ITIS 4166 Project</title>");
out.println("</head>");
out.println("<body>");
out.println("<div align='center'>");
out.println("<h1>ITIS 4166 Project - Login Page</h1>");
out.println("<h2>by: Tyler Everhart</h2>");
out.println("<br />");
out.println("<br />");
out.println("<br />");
out.println("<br />");
out.println("<table width='20%' border='1' cellspacing='1' cellpadding='1'>");
out.println("<form id='loginForm' name='loginForm' method='POST'>");
out.println("<tr>");
out.println("<td bgcolor='006F13' align='left' colspan='2'><b>Login</b></td>");
out.println("</tr>");
out.println("<tr>");
out.println("<td bgcolor='35D551' align='left'>Username:</td>");
out.println("<td bgcolor='35D551'>");
out.println("<input type='text' name='username' id='username' />");
out.println("</td>");
out.println("</tr>");
String passUsername = request.getParameter("username");
out.println("<tr>");
out.println("<td bgcolor='35D551' align='left'>Password:</td>");
out.println("<td bgcolor='35D551'>");
out.println("<input type='password' name='pwd' id='pwd' />");
out.println("</td>");
out.println("</tr>");
String passPwd = request.getParameter("pwd");
out.println("<tr>");
out.println("<td bgcolor='006F13' align='center' colspan='2'>");
out.println("<input type='submit' value='Submit' onclick='loginValidation()' /> ");
out.println("<input type='reset' value='Reset' />");
out.println("</td>");
out.println("</tr>");
out.println("</form>");
out.println("</table>");
out.println("<a href='Registration'>New User, Click Here to Register</a>");
out.println("</div>");
out.println("</body>");
out.println("</html>");
Class.forName(driver);
Connection connection = DriverManager.getConnection(url, username, password);
Statement statement = connection.createStatement();
String query = "SELECT UserName, PassWord FROM UserLogin";
ResultSet resultSet = statement.executeQuery(query);
HttpSession session = request.getSession(true);
while (resultSet.next()) {
if ((passUsername.equals(resultSet.getString("UserName")) && passPwd.equals(resultSet.getString("PassWord")))) {
String sessionID = UUID.randomUUID().toString();
session.setAttribute("username", passUsername);
session.setAttribute("sessionID", sessionID);
response.sendRedirect("Categories");
}
else if (passUsername.equals("") || passPwd.equals("")) {
out.println("Enter a username and password.");
}
else {
out.println("Either your username or password is incorrect or could not be found.");
out.println("Please try again, or click the link below to register.");
}
}
}
catch (ClassNotFoundException cnfe) {
System.err.println("Error loading driver: " + cnfe);
out.println("<tr>Error loading driver: " + cnfe + "</tr>");
}
catch (SQLException sqle) {
System.err.println("Error with connection: " + sqle);
out.println("<tr>Error with connection: " + sqle + "</tr>");
}
finally {
out.close();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP
* <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP
* <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
以下是注册页面的代码：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package hw5package;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.util.Random;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
*
* @author Tyler
*/
public class Registration extends HttpServlet {
/**
* Processes requests for both HTTP
* <code>GET</code> and
* <code>POST</code> methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
String driver = "oracle.jdbc.driver.OracleDriver";
String url = "jdbc:oracle:thin:@cci-ora02.uncc.edu:1521:class";
String username = "teverha4";
String password = "qwe123";
out.println("<html>");
out.println("<head>");
out.println("<title>ITIS 4166 Project</title>");
out.println("</head>");
out.println("<body>");
out.println("<div align='center'>");
out.println("<h1>ITIS 4166 Project - Registration Page</h1>");
out.println("<h2>by: Tyler Everhart</h2>");
out.println("<br />");
out.println("<br />");
out.println("<br />");
out.println("<br />");
out.println("<table width='25%' border='1' cellspacing='1' cellpadding='1'>");
out.println("<tr>");
out.println("<th bgcolor='006F13' align='left' colspan='2'>Register Account Information</th>");
out.println("</tr>");
out.println("<tr>");
out.println("<td bgcolor='35D551' align='left'>Requested Username:</td>");
out.println("<td bgcolor='35D551'>");
out.println("<form id='enterForm' name='enterForm'>");
out.println("<input type='text' name='requested_username' />");
out.println("</td>");
out.println("</tr>");
String passUsername = request.getParameter("requested_username");
out.println("<tr>");
out.println("<td bgcolor='35D551' align='left'>Password:</td>");
out.println("<td bgcolor='35D551'>");
out.println("<input type='password' name='pwd' />");
out.println("</td>");
out.println("</tr>");
String passPwd = request.getParameter("pwd");
out.println("<tr>");
out.println("<td bgcolor='35D551' align='left'>Confirm Password:</td>");
out.println("<td bgcolor='35D551'>");
out.println("<input type='password' name='pwd1' />");
out.println("</td>");
out.println("</tr>");
String passPwd1 = request.getParameter("pwd1");
out.println("<tr>");
out.println("<td bgcolor='006F13' align='center' colspan='2'>");
out.println("<input name='Submit' type='submit' value='Submit' /> ");
out.println("<input type='reset' value='Reset' />");
out.println("</td>");
out.println("</tr>");
out.println("</form>");
out.println("</table>");
out.println("</div>");
out.println("</body>");
out.println("</html>");
Class.forName(driver);
Connection connection = DriverManager.getConnection(url, username, password);
Statement statement = connection.createStatement();
HttpSession session = request.getSession();
if (passPwd.equals("") || passPwd1.equals("")) {
Integer registerError = Integer.valueOf(1);
session.setAttribute("registerError", registerError);
out.println("Please enter a valid password.");
}
else if (!passPwd.equals(passPwd1)) {
Integer registerError = Integer.valueOf(2);
session.setAttribute("registerError", registerError);
out.println("Your password and confirm password does not match.");
}
else {
String query2 = "INSERT INTO UserLogin (UserName, PassWord, StockAmt, TechnologyStock, UtilityStock) VALUES (?,?,?,?,?)";
PreparedStatement stmt = connection.prepareStatement(query2);
stmt.setString(1, passUsername);
stmt.setString(2, passPwd);
stmt.setInt(3, 0);
stmt.setInt(4, 0);
stmt.setInt(5, 0);
stmt.executeQuery();
session.setAttribute("sessionUsername", passUsername);
String sessionID = UUID.randomUUID().toString();
Random StockID1 = new Random();
StockID1.nextInt(10);
String insertDataSqlMicrosoft = "INSERT INTO StockInfo(StockID, UserID, Type, StockName, Owned, Price, Total) VALUES('" + StockID1 + "','" + passUsername + ",'Technology','Microsoft (MSFT)',0,32.75,0";
PreparedStatement stmtMicrosoft = connection.prepareStatement(insertDataSqlMicrosoft);
stmtMicrosoft.executeQuery();
Random StockID2 = new Random();
StockID2.nextInt(4);
String insertDataSqlIntel = "INSERT INTO StockInfo(StockID, UserID, Type, StockName, Owned, Price, Total) VALUES('" + StockID2 + "','" + passUsername + "','Technology','Intel (INTC)',0,26.75,0)";
PreparedStatement stmtIntel = connection.prepareStatement(insertDataSqlIntel);
stmtIntel.executeQuery();
Random StockID3 = new Random();
StockID3.nextInt(9);
String insertDataSqlDuke = "INSERT INTO StockInfo(StockID, UserID, Type, StockName, Owned, Price, Total) VALUES('" + StockID3 + "','" + passUsername + "','Utility','Duke Energy (DUK)',0,89.00,0";
PreparedStatement stmtDuke = connection.prepareStatement(insertDataSqlDuke);
stmtDuke.executeQuery();
Random StockID4 = new Random();
StockID4.nextInt(7);
String insertDataSqlCable = "INSERT INTO StockInfo(StockID, UserID, Type, StockName, Owned, Price, Total) VALUES('" + StockID4 + "','" + passUsername + "','Utility','Time Warner Cable (TWC)',0,30.00,0)";
PreparedStatement stmtCable = connection.prepareStatement(insertDataSqlCable);
stmtCable.executeQuery();
session.setAttribute("sessionID", sessionID);
response.sendRedirect("Categories");
}
}
catch (ClassNotFoundException cnfe) {
System.err.println("Error loading driver: " + cnfe);
out.println("<tr>Error loading driver: " + cnfe + "</tr>");
}
catch (SQLException sqle) {
System.err.println("Error with connection: " + sqle);
out.println("<tr>Error with connection: " + sqle + "</tr>");
} finally {
out.close();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP
* <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP
* <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
我想出了之前我从数据库中读取的问题，现在只有一个新问题。当我输入我验证过的用户名和密码存在于数据库中时，我没有被重定向到我想去的页面。此外，当我尝试注册新用户时，我没有重定向到该页面，并且出现错误消息：
连接错误：java.sql.SQLException：ORA-00917：缺少逗号
注册人的用户名和密码将发送到数据库，但程序不会将您重定向到相应的页面。
答案 0 :(得分：2)
检查您的驱动程序类和URL语法。
URL连接的语法是
jdbc:oracle:thin:@//[HOST][:PORT]/SERVICE
以下是我从OracleFAQ获得的工作样本。
import java.sql.*;
class Conn {
public static void main (String[] args) throws Exception
{
Class.forName ("oracle.jdbc.OracleDriver");
Connection conn = DriverManager.getConnection
("jdbc:oracle:thin:@//localhost:1521/orcl", "scott", "tiger");
// @//machineName:port/SID, userid, password
try {
Statement stmt = conn.createStatement();
try {
ResultSet rset = stmt.executeQuery("select BANNER from SYS.V_$VERSION");
try {
while (rset.next())
System.out.println (rset.getString(1)); // Print col 1
}
finally {
try { rset.close(); } catch (Exception ignore) {}
}
}
finally {
try { stmt.close(); } catch (Exception ignore) {}
}
}
finally {
try { conn.close(); } catch (Exception ignore) {}
}
}
}
我还想提出更多建议。
要查找正确的主机名/端口/服务，请检查tnsnames.ora文件。 查看OracleFAQ
以下是一些可以帮助您入门的链接：
http://docs.oracle.com/cd/B13789_01/java.101/b10979/getsta.htm
http://docs.oracle.com/javase/tutorial/jdbc/basics/gettingstarted.html
http://www.oracle.com/technetwork/indexes/downloads/index.html