У меня в проекте есть курс по Java, который мне нужен для создания страницы сайта.
Я почти закончил, но столкнулся с очень и очень странной проблемой.
В моем файле JSP янаписал этот код: не имеет значения, что этот код делает, но в целом он проверяет данные сеанса и вводит их в базу данных.
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="javax.servlet.http.HttpSession" language="java" %>
<%@ page import="Model.DataBase" language="java" %>
<% HttpSession session2 = request.getSession();
System.out.println("31");%>
<% String MySession = session2.toString();
System.out.println("31");
DataBase dbcon = new DataBase();
System.out.println("31");
System.out.println(MySession);
String username = dbcon.UsernameBySession(MySession);
if(username.equals(""))
response.sendRedirect("FrontPage.jsp");
;%>
Неудобно, когда код запускается, он выводит это на консоль:
, что означает, что ему не удалось пройти линию DataBase dbcon = new DataBase();.
Странная вещь в том, что он даже не входит в конструктор DataBase (), потому что, как вы можете видеть в файле базы данных (что опять-таки, не имеет значения, что он делает, толькопервые строки важны), у конструктора есть команда print ("*********************"), которая не выводится на консоль:
package Model;
import java.sql.*;
public class DataBase {
private Connection conn;
private Statement stt;
private Connection conn1;
private Statement stt1;
private Connection con1;
private Connection con2;
private Connection con3;
private Statement st1;
private ResultSet rs1;
public DataBase() {
System.out.println("********************************************************************************");
try {
System.out.println("31");
Class.forName("com.mysql.jdbc.Driver").newInstance();
System.out.println("31");
con1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/sudokudb", "root", "");
if (con1==null)
{
System.out.println("31");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/", "root", "");
System.out.println("32");
stt=conn.createStatement();
System.out.println("33");
String DBCreate = "CREATE DATABASE sudokudb";
System.out.println("34");
stt.executeQuery(DBCreate);
System.out.println("35");
conn1 = DriverManager.getConnection("jdbc:mysql://localhost:3306/sudokudb", "root", "");
System.out.println("36");
stt1=conn1.createStatement();
System.out.println("37");
String UsersTableCreate = "CREATE TABLE users"
+ "(username varchar(50) not NULL UNIQUE," +
"firstname varchar(50) not NULL," +
"lastname varchar(50) not NULL," +
"email varchar(90) not NULL," +
"password varchar(50) not NULL," +
"country varchar(50) not NULL)";
System.out.println("38");
String SessionTableCreate = "CREATE TABLE sessionid" +
"(session varchar(500)," +
"username varchar(50) not NULL UNIQUE)";
System.out.println("39");
stt.executeQuery(UsersTableCreate);
System.out.println("40");
stt.executeQuery(SessionTableCreate);
}
st1 = con1.createStatement();
} catch (ClassNotFoundException e) {
System.out.println("1");
e.printStackTrace();
} catch (SQLException e) {
System.out.println("2");
e.printStackTrace();
} catch (IllegalAccessException e) {
System.out.println("3");
e.printStackTrace();
} catch (InstantiationException e) {
System.out.println("4");
e.printStackTrace();
}
}
public int RegisterUser(String username, String firstname, String lastname, String password, String email, String country) {
try {
PreparedStatement query = con1.prepareStatement("insert into users (username, firstname, lastname, email, password, country) VALUES (?, ?, ?, ?, ?, ?)");
query.setString(1, username);
query.setString(2, firstname);
query.setString(3, lastname);
query.setString(4, email);
query.setString(5, password);
query.setString(6, country);
query.executeUpdate();
return 0;
} catch (com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException e1) {
return 1;
} catch (SQLException e) {
e.printStackTrace();
return 2;
}
}
public boolean loginUser(String Username, String password) {
try {
PreparedStatement query = con1.prepareStatement("SELECT * FROM users WHERE username = ? AND password = ?");
query.setString(1, Username);
query.setString(2, password);
rs1 = query.executeQuery();
return rs1.next();
} catch (SQLException e) {
e.printStackTrace();
return false;
}
}
public void LoginSession(String session, String username) throws SQLException {
try {
PreparedStatement query = con1.prepareStatement("insert into sessionid (session, username) VALUES (?, ?)");
query.setString(1, session);
query.setString(2, username);
query.executeUpdate();
}
catch (com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException e) {
String b = "\'";
username = b + username + b;
session = b + session + b;
String sql = "UPDATE sessionid SET username = " + username + " WHERE session = " + session;
PreparedStatement query = con1.prepareStatement(sql);
query.executeUpdate();
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public String UsernameBySession(String session2) {
try {
//PreparedStatement query = con1.prepareStatement("SELECT username FROM sessionid WHERE session = ?");
//query.setString(1,session);
//rs2 = query.executeQuery(q);
//String username = rs2.getString("username");
//return username;
con2 = DriverManager.getConnection("jdbc:mysql://localhost:3306/sudokudb", "root", "");
Statement stmt = con2.createStatement();
String b = "\'";
session2 = b + session2 + b;
String sql = "SELECT username FROM sessionid WHERE session = " + session2;
ResultSet rs2 = stmt.executeQuery(sql);
String username = "";
while (rs2.next()) {
username = rs2.getString("username");
System.out.println(username);
}
return username;
} catch (SQLException e) {
e.printStackTrace();
return "false";
}
}
public String[] LoadUser (String username){
try {
con3 = DriverManager.getConnection("jdbc:mysql://localhost:3306/sudokudb", "root", "");
Statement stmt = con3.createStatement();
String b = "\'";
username = b + username + b;
String sql = "SELECT * FROM users WHERE username = " + username;
ResultSet rs3 = stmt.executeQuery(sql);
String firstname = "";
String lastname = "";
String password = "";
String email = "";
String country = "";
while (rs3.next()) {
firstname = rs3.getString("firstname");
lastname = rs3.getString("lastname");
password = rs3.getString("password");
email = rs3.getString("email");
country = rs3.getString("country");
System.out.println(username);
}
String[] returnedarr = new String[5];
returnedarr[0] = firstname;
returnedarr[1] = lastname;
returnedarr[2] = password;
returnedarr[3] = email;
returnedarr[4] = country;
return returnedarr;
} catch (SQLException e) {
e.printStackTrace();
String[] faslearray = new String[1];
faslearray[0] = "false";
return faslearray;
}
}
}