项目启动连接mysql报错 另一个项目用的是同一个mysql不同数据库启动就没事

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:998)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1665)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1207)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2249)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2280)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2079)
at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:794)
at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:44)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.ai.util.DbFH.getCon(DbFH.java:178)
at com.ai.util.DbFH.getFHCon(DbFH.java:147)
at com.ai.util.DbFH.executeUpdateFH(DbFH.java:498)
at com.ai.filter.startFilter.reductionDbBackupQuartzState(startFilter.java:91)
at com.ai.filter.startFilter.init(startFilter.java:41)
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:273)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:254)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:372)
at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:98)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4584)
at org.apache.catalina.core.StandardContext$2.call(StandardContext.java:5262)
at org.apache.catalina.core.StandardContext$2.call(StandardContext.java:5257)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

@'localhost后面的数据库名字改了么

1、检查下你这个项目JDBC里面的数据库连接用户名和密码，确保正确。
2、检查你的该项目的connection jar包版本是否匹配
3、项目clean，重新build
4、重新导入项目
5、问度娘。。。。。

1.直接把密码改成空就能直接连接

2.手动数据库测试连接，找到正确用户名密码，在进行正确填写连接

在你的查询语句别名前面加上AS试试看：

SELECT count (*)
FROM (SELECT t.mechno
          , count ( *)
      FROM (SELECT *
            FROM boc_payinfo " + whereStr + ") AS t
          , mp_merinfo AS m
      WHERE t.mechno = m.mechno
      GROUP BY t.mechno) AS b

不好意思，上面的回复错提问了。

1.检查用户名和密码是否正确，有时候没写对就有问题。
2.有可能mysql没有启动服务，试一下net start mysql命令

密码错误啊，哥。。。

我也出现这个问题，配置是一样的，直接复制过来的，发布的也是同一台机器，但是一个项目可以访问，另一个就访问不了。
报错："Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: Access denied for user 'root'@'x.x.x.x' (using password: NO)"