I'm using the NetBeans IDE(6.8). I have a DB class :
package garits;
import java.io.Serializable;
import java.sql.*;
import java.util.Properties;
public class DB implements Serializable{
private static final long serialVersionUID = 1L;
String dbURL = "jdbc:mysql:///team_project";
String user = "root";
String pwd = "arsenal";
String dbDriver = "com.mysql.jdbc.Driver";
private Connection dbCon;
private ResultSet r;
private Statement s;
public DB()
{}
public boolean connect() throws ClassNotFoundException,SQLException{
Class.forName(dbDriver);
Properties props = new Properties();
props.put(user, "root");
props.put(pwd, "arsenal");
props.put("charSet", "UTF-8");
props.put("lc_ctype", "UTF-8");
dbCon = DriverManager.getConnection(dbURL,props);
//dbCon = DriverManager.getConnection(dbURL,user,pwd);
return true;
}
public void close() throws SQLException{
dbCon.close();
if(r!=null)
r.close();
if(s!=null)
s.close();
}
public ResultSet execSQL(String sql) throws SQLException{
s = dbCon.createStatement();
r = s.executeQuery(sql);
return (r == null) ? null : r;
}
public int updateSQL(String sql) throws SQLException{
s = dbCon.createStatement();
int r = s.executeUpdate(sql);
return (r == 0) ? 0 : r;
}
public int updateSQL(String sql, String getID) throws SQLException{
s = dbCon.createStatement();
int autoIncValue = -1;
s.executeUpdate(sql, Statement.RETURN_GENERATED_KEYS);
ResultSet rs = s.getGeneratedKeys();
if (rs.next()) {开发者_运维技巧
autoIncValue = rs.getInt(1);
}
return autoIncValue;
}
}
The jar file is im my library, but whenever I try to connect:
private void loginButtonActionPerformed(java.awt.event.ActionEvent evt) {
String result ="";
DB db = new DB();
try{
db.connect();
String query = "Select Role From User_Account Where Username=jTextField1.getText()AND Where Password=jTextField2.getText(); ";
ResultSet rs=db.execSQL(query);
while(rs.next())
{
result = rs.getString("Role");
}
if(result.equals(""))
{
JOptionPane.showMessageDialog(loginButton,"Access denied","Error Message",JOptionPane.ERROR_MESSAGE);
}
else if(result.equals("Administrator"))
{
MainPage_Admin admin = new MainPage_Admin();
}
}
catch(Exception e)
{
System.out.println("An error has occurred");
}
}
I get an error(the exception is caught)-the name of the database is "team_project" and password is "arsenal"-any ideas appreciated. I'm new to JDBC.
First step: use at least e.printStackTrace()
in your catch-block to get some information from the exception. Otherwise you'll just be guessing.
MySQL database url connection property is wrong
jdbc:mysql://localhost:3306/<your database name>
instead of you are giving
jdbc:mysql:///team_project
modify and execute the program and better to handle the exception within the try/catch block instead of throws.
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