数据库连接失败
java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: NO)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2941)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:868)
at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3340)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1238)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2743)
at com.mysql.jdbc.Connection.<init>(Connection.java:1553)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(DriverManager.java:579)
at java.sql.DriverManager.getConnection(DriverManager.java:221)
at util.DBHelper.getConnection(DBHelper.java:34)
at util.DBHelper.main(DBHelper.java:43)