When the app is launched, it will be stuck in:
08:22:58,221 DEBUG integratorserviceimpl:46-adding Integrator [ Org.hibernate.cfg.beanvalidation.BeanValidationIntegrator].
08:22:58,226 DEBUG integratorserviceimpl:46-adding Integrator [Org.hibernate.secure.spi.JaccIntegrator].
08:22:58,229 DEBUG integratorserviceimpl:46-adding Integrator [ Org.hibernate.cache.internal.CollectionCacheInvalidator].
08:22:58,320 INFO version:37-hhh000412:hibernate Core {5.0.7.Final}
08:22:58,322 INFO environment:213-hhh000206:hibernate.properties not found
08:22:58,324 INFO Environment:317-hhh000021:bytecode Provider Name:javassist
08:22:58,353 DEBUG localxmlresourceresolver:57-interpreting public/system identifier: [-//hibernate/hibernate Configuration DTD 3.0//en]-[HTTP://WWW.HIBERNATE.ORG/DTD/HIBERNATE-CONFIGURATION-3.0.DTD]
08:22:58,353 DEBUG localxmlresourceresolver:85-recognized hibernate-configuration identifier; Attempting to resolve on classpath under org/hibernate/
08:22:58,357 DEBUG Jaxbcfgprocessor:116-cfg.xml document did not define namespaces; Wrapping in custom event reader to introduce namespace information
08:22:58,511 DEBUG configuration:722-building Session factory using internal Standardserviceregistrybuilder
08:22:58,519 DEBUG servicebinding:68-overriding Existing service binding [Org.hibernate.secure.spi.JaccService]
08:22:58,519 DEBUG configuration:653-building Session factory using provided Standardserviceregistry
08:22:58,538 DEBUG Regionfactoryinitiator:88-cache Region factory: Org.hibernate.cache.internal.NoCachingRegionFactory
08:22:58,546 INFO version:66-hcann000001:hibernate Commons Annotations {5.0.1.Final}
08:22:58,632 INFO connectionproviderinitiator:187-hhh000130:instantiating Explicit connection provider: Org.hibernate.connection.C3P0ConnectionProvider
08:22:58,637 INFO c3p0connectionprovider:117-hhh010002:c3p0 using Driver:com.mysql.jdbc.Driver at url:jdbc:mysql:/// Exam
08:22:58,638 INFO c3p0connectionprovider:118-hhh10001001:connection Properties: {user=root, password=****, Autocommit=false}
08:22:58,638 INFO C3p0connectionprovider:121-hhh10001003:autocommit Mode:false
08:22:58,934 INFO C3P0CONNECTIONPROVIDER:201-HHH10001007:JDBC Isolation Level: <unknown>
It then throws the following exception:
08:23:29,343 WARN basicresourcepool:1851-com[email Protected]12bfebe--acquisition attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition at tempts (30). Last acquisition attempt exception:
java.sql.SQLException: Unknown system variable ' language '
At Com.mysql.jdbc.SQLError.createSQLException (sqlerror.java:963)
At Com.mysql.jdbc.MysqlIO.checkErrorPacket (mysqlio.java:3966)
At Com.mysql.jdbc.MysqlIO.checkErrorPacket (mysqlio.java:3902)
At Com.mysql.jdbc.MysqlIO.sendCommand (mysqlio.java:2526)
At Com.mysql.jdbc.MysqlIO.sqlQueryDirect (mysqlio.java:2673)
At Com.mysql.jdbc.ConnectionImpl.execSQL (connectionimpl.java:2545)
At Com.mysql.jdbc.ConnectionImpl.execSQL (connectionimpl.java:2503)
At Com.mysql.jdbc.StatementImpl.executeQuery (statementimpl.java:1369)
At Com.mysql.jdbc.ConnectionImpl.loadServerVariables (connectionimpl.java:3833)
At Com.mysql.jdbc.ConnectionImpl.initializePropsFromServer (connectionimpl.java:3283)
At Com.mysql.jdbc.ConnectionImpl.connectOneTryOnly (connectionimpl.java:2297)
At Com.mysql.jdbc.ConnectionImpl.createNewIO (connectionimpl.java:2083)
At com.mysql.jdbc.connectionimpl.<init> (connectionimpl.java:806)
At com.mysql.jdbc.jdbc4connection.<init> (jdbc4connection.java:47)
At Sun.reflect.GeneratedConstructorAccessor10.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:404)
At Com.mysql.jdbc.ConnectionImpl.getInstance (connectionimpl.java:410)
At Com.mysql.jdbc.NonRegisteringDriver.connect (nonregisteringdriver.java:328)
At Com.mchange.v2.c3p0.DriverManagerDataSource.getConnection (drivermanagerdatasource.java:146)
At Com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection ( wrapperconnectionpooldatasource.java:195)
At Com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection ( wrapperconnectionpooldatasource.java:184)
At Com.mchange.v2.c3p0.impl.c3p0pooledconnectionpool$1pooledconnectionresourcepoolmanager.acquireresource ( c3p0pooledconnectionpool.java:200)
At Com.mchange.v2.resourcepool.BasicResourcePool.doAcquire (basicresourcepool.java:1086)
At Com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess ( basicresourcepool.java:1073)
At com.mchange.v2.resourcepool.basicresourcepool.access$800 (basicresourcepool.java:44)
At Com.mchange.v2.resourcepool.basicresourcepool$scatteredacquiretask.run (basicresourcepool.java:1810)
At Com.mchange.v2.async.threadpoolasynchronousrunner$poolthread.run (threadpoolasynchronousrunner.java:635 )
08:23:29,346 WARN basicresourcepool:1851-com[email Protected]125ba1c--acquisition attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition at tempts (30). Last acquisition attempt exception:
java.sql.SQLException: Unknown system variable ' language '
At Com.mysql.jdbc.SQLError.createSQLException (sqlerror.java:963)
At Com.mysql.jdbc.MysqlIO.checkErrorPacket (mysqlio.java:3966)
At Com.mysql.jdbc.MysqlIO.checkErrorPacket (mysqlio.java:3902)
At Com.mysql.jdbc.MysqlIO.sendCommand (mysqlio.java:2526)
At Com.mysql.jdbc.MysqlIO.sqlQueryDirect (mysqlio.java:2673)
At Com.mysql.jdbc.ConnectionImpl.execSQL (connectionimpl.java:2545)
At Com.mysql.jdbc.ConnectionImpl.execSQL (connectionimpl.java:2503)
At Com.mysql.jdbc.StatementImpl.executeQuery (statementimpl.java:1369)
At Com.mysql.jdbc.ConnectionImpl.loadServerVariables (connectionimpl.java:3833)
At Com.mysql.jdbc.ConnectionImpl.initializePropsFromServer (connectionimpl.java:3283)
At Com.mysql.jdbc.ConnectionImpl.connectOneTryOnly (connectionimpl.java:2297)
At Com.mysql.jdbc.ConnectionImpl.createNewIO (connectionimpl.java:2083)
At com.mysql.jdbc.connectionimpl.<init> (connectionimpl.java:806)
At com.mysql.jdbc.jdbc4connection.<init> (jdbc4connection.java:47)
At Sun.reflect.GeneratedConstructorAccessor10.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:404)
At Com.mysql.jdbc.ConnectionImpl.getInstance (connectionimpl.java:410)
At Com.mysql.jdbc.NonRegisteringDriver.connect (nonregisteringdriver.java:328)
At Com.mchange.v2.c3p0.DriverManagerDataSource.getConnection (drivermanagerdatasource.java:146)
At Com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection ( wrapperconnectionpooldatasource.java:195)
At Com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection ( wrapperconnectionpooldatasource.java:184)
At Com.mchange.v2.c3p0.impl.c3p0pooledconnectionpool$1pooledconnectionresourcepoolmanager.acquireresource ( c3p0pooledconnectionpool.java:200)
At Com.mchange.v2.resourcepool.BasicResourcePool.doAcquire (basicresourcepool.java:1086)
At Com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess ( basicresourcepool.java:1073)
At com.mchange.v2.resourcepool.basicresourcepool.access$800 (basicresourcepool.java:44)
At Com.mchange.v2.resourcepool.basicresourcepool$scatteredacquiretask.run (basicresourcepool.java:1810)
At Com.mchange.v2.async.threadpoolasynchronousrunner$poolthread.run (threadpoolasynchronousrunner.java:635 )
08:23:29,343 WARN basicresourcepool:1851-com[email protected]1d7070d--acquisition attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition at tempts (30). Last acquisition attempt exception:
Workaround: This issue is caused by an incompatibility between the MySQL driver version and the MySQL version, and an earlier version of the driver can be resolved. For example: Change to Mysql-connector-java-5.1.6.jar
Hibernate stuck and then error java.sql.SQLException:Unknown system variable ' language ' exception