package util;

import java.sql.Connection;
import java.sql.DriverManager;
public class DBHelper {
?private static final String driver = "com.mysql.jdbc.Driver"; //數據庫驅動
?//連接數據庫的URL地址
?private static final String url="jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8";
?private static final String username="root";//數據庫的用戶名
?private static final String password="";//數據庫的密碼
???
?private static Connection conn=null;
?
?//靜態代碼塊負責加載驅動
?static
?{
??try
??{
???Class.forName(driver);
??}
??catch(Exception ex)
??{
???ex.printStackTrace();
??}
?}
?
?//單例模式返回數據庫連接對象
?public static Connection getConnection() throws Exception
?{
??if(conn==null)
??{
???conn = DriverManager.getConnection(url, username, password);
???return conn;
??}
??return conn;
?}
?
?public static void main(String[] args) {
??
??try
??{
???? Connection conn = DBHelper.getConnection();
???? if(conn!=null)
???? {
????? System.out.println("數據庫連接正常！");
???? }
???? else
???? {
????? System.out.println("數據庫連接異常！");
???? }
??}
??catch(Exception ex)
??{
???ex.printStackTrace();
??}
??
?}
}

Sat Mar 24 02:30:06 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: NO)
?at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
?at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976)
?at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912)
?at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
?at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1714)
?at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1224)
?at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2190)
?at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2221)
?at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2016)
?at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
?at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
?at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
?at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
?at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
?at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
?at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
?at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
?at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
?at java.sql.DriverManager.getConnection(DriverManager.java:664)
?at java.sql.DriverManager.getConnection(DriverManager.java:247)
?at util.DBHelper.getConnection(DBHelper.java:32)
?at util.DBHelper.main(DBHelper.java:42)