Javaweb大作业代码

package beans; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBHelper { public String url= "jdbc:mysql://localhost:3306/web?serverTimezone=GMT"; Connection connection; public DBHelper(String sqlName, String password) { try { Class.forName("com.mysql.cj.jdbc.Driver"); } catch (ClassNotFoundException e) { System.out.println("加载数据库驱动失败"); e.printStackTrace(); } try { connection = (Connection) DriverManager.getConnection(url, sqlName, password); System.out.println("链接数据库成功"); } catch (SQLException e) { System.out.println("链接数据库失败"); e.printStackTrace(); } } public void ExecuteInsert(String sql) { try { Statement stmt=connection.createStatement(); stmt.execute(sql); } catch (SQLException e) { System.out.println("ExecuteInsert()Exception:SQLException"); e.printStackTrace(); } } public void ExecuteDelete(String sql){ try{ Statement stmt=connection.createStatement(); stmt.execute(sql); }catch(SQLException e){ System.out.println("ExecuteDelete()Exception:SQLException"); e.printStackTrace(); } } public void ExecuteUpdate(String sql) { try { Statement stmt=connection.createStatement(); stmt.executeUpdate(sql); } catch (SQLException e) { System.out.println("ExecuteUpdate()Exception:SQLException"); e.printStackTrace(); } } public ResultSet ExecuteQuery(String sql) throws SQLException { Statement stmt=connection.createStatement(); ResultSet rs = stmt.executeQuery(sql); return rs; } public static void main(String[] args) { DBHelper db= new DBHelper("root", "root"); } }