测试代码：
package www; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; public class how { //属性 private static String driver="com.mysql.cj.jdbc.Driver"; //JDBC驱动类名 private static final String URL="jdbc:mysql://localhost:3306/hgs?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&useSSL=false"; private static final String USER="root"; //用户名 private static final String PASSWORD="root"; //密码 //创建连接 public static Connection getConnection(){ Connection conn=null; try { Class.forName(driver); //加载jdbc驱动 conn=DriverManager.getConnection(URL, USER, PASSWORD); //创建连接 //System.out.println("创建连接成功！"); } catch (Exception e) { e.printStackTrace(); } return conn; } //关闭连接 public static void close(Connection conn,Statement st,ResultSet rs){ if(rs!=null){ try { rs.close(); //System.out.println("关闭rs成功！"); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } if(st!=null){ try { st.close(); //System.out.println("关闭st成功！"); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } if(conn!=null){ try { conn.close(); //System.out.println("关闭conn成功！"); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } } } public static void main(String[] args) { try { Connection conn = how.getConnection(); if(conn!=null) { System.out.println("数据库连接正常！"); } else { System.out.println("数据库连接异常！"); } } catch(Exception ex) { ex.printStackTrace(); } } }