用Java連接到MySQL

Question

好吧，我真的很新的Java，我不知道如何真正做到這一點。如果你們能幫助我，那麼我可能會了解更多。我有我的主類（Mysql.java）和一個Connection類（Connection.java）現在我希望它使用Connection.java部分連接到數據庫。但我想從Mysql.java使用它。我現在這個權利：

Mysql.java

public class Mysql { 

    public static void main(String[] args) { 
     Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); 
     int w = screenSize.width; 
     JFrame frame = new MainFrame(w/5, 100, 2*w/5, 0); 
     frame.show(); 
     new Connection(); 
    } 


} 
class MainFrame extends JFrame { 
    MainFrame(int width, int height, int x, int y) { 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setTitle("Todothelydoo - To do planner"); 
     setSize(width, height); 
     setLocation(x, y); 
     JPanel mainPanel = new JPanel(); 
     mainPanel.setBackground(Color.blue); 
    } 
} 

Connection.java

public class Connection { 
    public static Connection getConnection() throws SQLException { 
     Connection conn = null; 
     try 
     { 
      Class.forName("com.mysql.jdbc.Driver"); 
      String url = "jdbc:mysql://h2318966.stratoserver.net/"; 
      String user = "root"; 
      String password = ""; 
      conn = (Connection) DriverManager.getConnection(url, user, password); 
      System.out.println("Connection established"); 
     } 
     catch(ClassNotFoundException e) 
     { 
      System.out.println(e.getMessage()); 
      System.exit(0); 
     } 
     catch(SQLException e) 
     { 
      System.out.println(e.getMessage()); 
      System.exit(0); 
     } 
     return conn; 
    } 
} 

我試着用在mysql.java但即時通訊新的連接可能是一個完全白癡。如果你們能幫助我，那會很棒。

Answer 1

您可以在url字符串中使用您自己的主機和數據庫名稱的以下代碼。我已經測試過它。

注：包含的mysql-connector.jar在您的項目

Mysql.java

import java.awt.Color; 
    import java.awt.Dimension; 
    import java.awt.Toolkit; 
    import java.sql.SQLException; 

    import javax.swing.JFrame; 
    import javax.swing.JPanel; 

    public class Mysql { 

    public static void main(String[] args) { 
     Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); 
     int w = screenSize.width; 
     JFrame frame = new MainFrame(w/5, 100, 2*w/5, 0); 
     frame.show(); 
     try { 
      new Connection().getConnection(); 
     } catch (SQLException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 
    } 


} 
class MainFrame extends JFrame { 
    MainFrame(int width, int height, int x, int y) { 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setTitle("Todothelydoo - To do planner"); 
     setSize(width, height); 
     setLocation(x, y); 
     JPanel mainPanel = new JPanel(); 
     mainPanel.setBackground(Color.blue); 
    } 
} 

Connection.java

import java.sql.DriverManager; 
import java.sql.SQLException; 

public class Connection { 
    public static java.sql.Connection getConnection() throws SQLException { 
     java.sql.Connection conn = null; 
     try 
     { 
      Class.forName("com.mysql.jdbc.Driver"); 
      String url = "jdbc:mysql://localhost/database_name"; 
      String user = "root"; 
      String password = ""; 
      conn = DriverManager.getConnection(url, user, password); 
      System.out.println("Connection established"); 
     } 
     catch(ClassNotFoundException e) 
     { 
      System.out.println(e.getMessage()); 
      System.exit(0); 
     } 
     catch(SQLException e) 
     { 
      System.out.println(e.getMessage()); 
      System.exit(0); 
     } 
     return conn; 
    } 
} 

Answer 2

公共類Mysql的擴展Connectionn {

public static void main(String[] args) { 
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); 
    int w = screenSize.width; 
    JFrame frame = new MainFrame(w/5, 100, 2*w/5, 0); 
    frame.show(); 
    Connectionn con=new Connectionn(); 
    try { 
     con.getConnection(); 
    } catch (SQLException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
} 

}