JDBC编程工具类 Dbconnection

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.swing.JOptionPane;
import com.mysql.jdbc.Statement;
public class DbConnection {
  //驱动类的类名
  private static final String DRIVERNAME="com.mysql.jdbc.Driver";
  //连接数据的URL路径
  private static final String URL="jdbc:mysql://127.0.0.1:3306/moviedb";
  //数据库登录账号
  private static final String USER="root";
  //数据库登录密码
  private static final String PASSWORD="root123";
  //加载驱动
  static{
    try {
      Class.forName(DRIVERNAME);
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }
    //获取数据库连接
  public static Connection getConnection() {
            try {
    return DriverManager.getConnection(URL,USER,PASSWORD);
             } catch (SQLException e) { 
    e.printStackTrace();
             }
      return null;
  }
  //查询
  public static ResultSet query(String sql) {
    System.out.println(sql);
    //获取连接
    Connection connection=getConnection();
    PreparedStatement psd;
    try {
      psd = connection.prepareStatement(sql);
      return psd.executeQuery();
    } catch (SQLException e) {
      JOptionPane.showMessageDialog(null,"执行语句出错\n"+e.toString());
      e.printStackTrace();
    }
    return null;
  }
  //增、删、改、查
    public static int updataInfo(String sql) {
      System.out.println(sql);
      //获取连接
      Connection connection=getConnection();
      try {
        PreparedStatement psd=connection.prepareStatement(sql);
        return psd.executeUpdate();
      } catch (SQLException e) {
        JOptionPane.showMessageDialog(null,"执行语句出错\n"+e.toString());
        e.printStackTrace();
      }
      return 0;
    }
  //关闭连接
  public static void colse(ResultSet rs,Statement stmt,Connection  conn) throws Exception{
    try { 
      if (rs != null){
        rs.close(); 
      }
            if (stmt != null){
              stmt.cancel(); 
            }
     if (conn != null) { conn.close(); }
     } catch (Exception e) {
       e.printStackTrace(); throw new Exception();
     }
  }
}