错误描述：使用的是C3P0连接池
Spring整合Mybatis时出现错误
java.sql.SQLException: Access denied for user ‘GC‘@‘localhost‘ (using password: YES)
DEBUG [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1] - An exception occurred while acquiring a poolable resource. Will retry. java.sql.SQLException: Access denied for user ‘GC‘@‘localhost‘ (using password: YES) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835) at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455) at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:199) at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014) at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32) at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810) at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547) Process finished with exit code -1
问题解决：下图中的username、password 改为name、pwd （其实只修改username就可以 为了后面不出问题最好俩个都修改）
注意：我的错误是因为没有按照C3P0连接池的格式 （这个问题也可能是数据库密码错误）
Access denied for user 'GC'@'localhost' (using password: YES)