用户管理系统开发（dbutil）

util主要管数据库的连接 提供连接供其他层使用

package dbutill;
import java.sql.*;
import java.util.Scanner;
public class db {
public static final String URL = "jdbc:mysql://localhost:3306/text?characterEncoding=utf8&useSSL=false&serverTimezone=UTC";
public static final String USER = "root";
public static final String PASSWORD = "123";
public static final String DRIVER="com.mysql.cj.jdbc.Drive";
public static Connection getConn () throws ClassNotFoundException {
Connection conn=null;
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e1) {
// TODO 自动生成的 catch 块
e1.printStackTrace();
}
try {
conn = DriverManager.getConnection(URL,USER,PASSWORD);
System.out.println("连接成功");

} catch (SQLException e) {
// TODO: handle exception
e.printStackTrace();
}
return conn;
}
public static void close (Statement state, Connection conn) {
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close (ResultSet rs, Statement state, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args) throws Exception {
Connection conn=getConn();
// conn.close();
}

}