Linux下添加MySql组件后报无权限问题解决

Tomcat日志报错如下：

Caused by: java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1084)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:926)
    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1748)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1288)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2506)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2539)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2321)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
    at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
    at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:294)
    at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1247)
    at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1221)
    ... 85 more

使用mysql命令行连接，依旧报错：

root@NaiYou:~# mysql -u root
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
root@NaiYou:~# mysql -u root -p
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

尝试了N种方法,最终用以下方法解决了：

1、首先到安装目录下找到初始化的账号密码
root@NaiYou:~# cd /etc/mysql/
root@NaiYou:/etc/mysql# ls
conf.d  debian.cnf  debian-start  my.cnf
2、查看账户密码
root@NaiYou:/etc/mysql# cat debian.cnf
# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = debian-sys-maint
password = XXXXXXXX
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = debian-sys-maint
password = XXXXXXXX
socket   = /var/run/mysqld/mysqld.sock
basedir  = /usr
3、使用client的账户密码登陆mysql命令行
root@NaiYou:/etc/mysql# mysql -udebian-sys-maint -p
4、更新root用户的密码
mysql> use mysql;
mysql> UPDATE user SET Password=PASSWORD('123456') where USER='root';
mysql> quit
5、现在可以用Root用户登陆了root@NaiYou:/etc/mysql# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2247
Server version: 5.5.44-0ubuntu0.14.04.1 (Ubuntu)