Database cannot connect to JDBC

Resolution: Connections could not being acquired from the underlying database! Blog Category:

• Problem solving
• Database
• IBatis

Og4j:warn See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Org.quartz.SchedulerConfigException:Failure occured during job recovery. [See nested exception:org.quartz.JobPersistenceException:Failed to obtain DB connection from data source ' MyDS ': java.sq L.sqlexception:connections could not being acquired from the underlying database! [See nested exception:java.sql.SQLException:Connections could not being acquired from the underlying database!]]
At org.quartz.impl.jdbcjobstore.JobStoreSupport.schedulerStarted (jobstoresupport.java:693)
At Org.quartz.core.QuartzScheduler.start (quartzscheduler.java:580)
At Org.quartz.impl.StdScheduler.start (stdscheduler.java:142)
At Org.quartz.ee.servlet.QuartzInitializerListener.contextInitialized (quartzinitializerlistener.java:198)
At Org.apache.catalina.core.StandardContext.listenerStart (standardcontext.java:3830)
At Org.apache.catalina.core.StandardContext.start (standardcontext.java:4337)
At Org.apache.catalina.core.ContainerBase.start (containerbase.java:1045)
At Org.apache.catalina.core.StandardHost.start (standardhost.java:719)
At Org.apache.catalina.core.ContainerBase.start (containerbase.java:1045)
At Org.apache.catalina.core.StandardEngine.start (standardengine.java:443)
At Org.apache.catalina.core.StandardService.start (standardservice.java:516)
At Org.apache.catalina.core.StandardServer.start (standardserver.java:710)
At Org.apache.catalina.startup.Catalina.start (catalina.java:566)
At Sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
At Sun.reflect.NativeMethodAccessorImpl.invoke (nativemethodaccessorimpl.java:39)
At Sun.reflect.DelegatingMethodAccessorImpl.invoke (delegatingmethodaccessorimpl.java:25)
At Java.lang.reflect.Method.invoke (method.java:597)
At Org.apache.catalina.startup.Bootstrap.start (bootstrap.java:288)
At Org.apache.catalina.startup.Bootstrap.main (bootstrap.java:413)
caused by:org.quartz.JobPersistenceException:Failed to obtain DB connection from data source ' MyDS ': Java.sql.SQLExcepti On:connections could not being acquired from the underlying database! [See nested exception:java.sql.SQLException:Connections could not being acquired from the underlying database!]
At Org.quartz.impl.jdbcjobstore.JobStoreSupport.getConnection (jobstoresupport.java:777)
At Org.quartz.impl.jdbcjobstore.JobStoreTX.getNonManagedTXConnection (jobstoretx.java:71)
At Org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock (jobstoresupport.java:3774)
At Org.quartz.impl.jdbcjobstore.JobStoreSupport.executeInNonManagedTXLock (jobstoresupport.java:3739)
At Org.quartz.impl.jdbcjobstore.JobStoreSupport.recoverJobs (jobstoresupport.java:833)
At org.quartz.impl.jdbcjobstore.JobStoreSupport.schedulerStarted (jobstoresupport.java:691)
... More
caused By:java.sql.SQLException:Connections could not being acquired from the underlying database!
At Com.mchange.v2.sql.SqlUtils.toSQLException (sqlutils.java:106)
At Com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection (c3p0pooledconnectionpool.java:529 )
At Com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection (abstractpoolbackeddatasource.java:128)
At Org.quartz.utils.PoolingConnectionProvider.getConnection (poolingconnectionprovider.java:247)
At Org.quartz.utils.DBConnectionManager.getConnection (dbconnectionmanager.java:108)
At Org.quartz.impl.jdbcjobstore.JobStoreSupport.getConnection (jobstoresupport.java:774)
... More
caused By:com.mchange.v2.resourcepool.cannotacquireresourceexception:a Resourcepool could notacquire A resource from Its primary factory or source.
At Com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable (basicresourcepool.java:1319)
At Com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource (basicresourcepool.java:557)
At Com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource (basicresourcepool.java:477)
At Com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection (c3p0pooledconnectionpool.java:525 )
... More

The above problems may be caused by the following reasons:

1, driver configuration error: Driver=com.mysql.jdbc.driver
2, database connection address error: Url=jdbc:mysql://localhost:3306/test?3useunicode=true&characterencoding=utf8
3, password or account error: Username=root
Password=root

4, the database is not started or is not authorized to access

5, the project did not introduce the corresponding drive jar package Mysql-connector-java-5.1.6-bin.jar

6,MySQL root does not have remote access permissions, need to increase permissions, the steps to increase permissions are as follows:
Go to MySQL database:
Grant all privileges on * * to ' root ' @ '% ' identified by ' root ' with GRANT option;
Flush privileges;

If you have encountered the above problems, but the reason is not the above 5, please share the solution, thank you

Database cannot connect to JDBC