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How to resolve "Caused by: org.hibernate.HibernateException: Unable to access lob stream"

I have recently Upgraded my application.
Upgradation details:
- Java 6 to Java 8
- Hibernate 3 to Hibernate 3.6.10
- Spring 2.5 to Spring 4
- JBoss EAP 6 to JBoss EAP 7
I am trying to save some values which include some text values and files(Clob). The data is getting saved but I am getting an exception on the next hibernate operation.
Caused by: org.hibernate.HibernateException: Unable to access lob stream
at org.hibernate.type.descriptor.java.ClobTypeDescriptor.unwrap(ClobTypeDescriptor.java:117)
at org.hibernate.type.descriptor.java.ClobTypeDescriptor.unwrap(ClobTypeDescriptor.java:46)
at org.hibernate.type.descriptor.sql.ClobTypeDescriptor$3$1.doBind(ClobTypeDescriptor.java:83)
at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:91)
at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:283)
at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:278)
at org.hibernate.type.AbstractSingleColumnStandardBasicType.nullSafeSet(AbstractSingleColumnStandardBasicType.java:89)
at org.hibernate.persister.entity.AbstractEntityPersister.dehydrate(AbstractEntityPersister.java:2184)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2559)
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2495)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2822)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:113)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at com.honeywell.cdd.dao.RptGrpDAOImpl.removeUnConfigGrpMTDT(RptGrpDAOImpl.java:2373)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.orm.hibernate3.HibernateInterceptor.invoke(HibernateInterceptor.java:112)
... 68 more
Caused by: java.sql.SQLException: could not reset reader
at org.hibernate.engine.jdbc.ClobProxy.resetIfNeeded(ClobProxy.java:178)
at org.hibernate.engine.jdbc.ClobProxy.getCharacterStream(ClobProxy.java:89)
at org.hibernate.engine.jdbc.ClobProxy.invoke(ClobProxy.java:121)
at com.sun.proxy.$Proxy133.getCharacterStream(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.hibernate.engine.jdbc.SerializableClobProxy.invoke(SerializableClobProxy.java:74)
at com.sun.proxy.$Proxy132.getCharacterStream(Unknown Source)
at org.hibernate.type.descriptor.java.ClobTypeDescriptor.unwrap(ClobTypeDescriptor.java:114)
... 98 more
I am not able to find out exact cause of this exception.
> The Same Code is working fine in the older configuration

"The Same Code is working fine in the older configuration"
is not really relevant ... unless you want to submit a but report to someone.
Lets look at what the nested exception:
Caused by: java.sql.SQLException: could not reset reader
The stacktrace indicates that something is calling getCharacterStream() on a Clob proxy and that is failing when the proxy attempts to reset the proxy's reader. The failure is (presumably) occurring because the JDBC object wrapped by the proxy doesn't allow a reader to be reset.
So why is this happening?
Again ... presumably ... something in your application has tried to call getCharacterStream() twice on a Clob proxy.
My guess is that you are (implicitly) using Clob objects as if they were in-memory files ... to avoid reading them when you don't need to. Except that sometimes you need to, and this is interfering with the persisting.

How to handle database connection fail with Hibernate, C3P0 on Java EE?

I am working on Java EE JSF application using Hibernate with C3P0 connection pool. I have tried to search anything possible and impossible and tried many things, but couldnt figure this out.
The problem is handling database connection fail, for example when database is shut down. I couldn't find a way how to catch ecfeption which I could use to show error status on user interface. The only thing I could do is see some exceptions in console:
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at sun.reflect.GeneratedConstructorAccessor408.newInstance(Unknown Source)
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:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1015)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2404)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2325)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.GeneratedConstructorAccessor407.newInstance(Unknown Source)
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:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:347)
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:648)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor404.newInstance(Unknown Source)
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:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1129)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:358)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2498)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2343)
... 18 more
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:579)
at java.net.Socket.connect(Socket.java:528)
at java.net.Socket.<init>(Socket.java:425)
at java.net.Socket.<init>(Socket.java:241)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:308)
... 20 more
]]
But I can't catch this, it's just on console and it's not even printed in web browser response (client thread does not receive any exception, it's just hanging while trying to load the page for infinity).
Here is my C3P0 configuration:
c3p0.testConnectionOnCheckout=true
c3p0.idleConnectionTestPeriod=60
c3p0.acquireIncrement=1
c3p0.preferredTestQuery=SELECT 1
c3p0.acquireRetryAttempts=1
My question is: How to handle case of database connection fail in the user-friendly way?

You could use the Omnifaces FullAjaxExceptionHandler to display whatever you want for the exception. See the following link to documentation:
http://showcase.omnifaces.org/exceptionhandlers/FullAjaxExceptionHandler

OK, after of few days of work I have constructed a solution.
The problem was that just typical Hibernate session did not throw any exception while using it without database connected. But this piece of code does throw an exception when database not connected (so it can be used as a test):
Properties p = hibernateConnection.getCfg().getProperties();
String url = p.getProperty("hibernate.connection.url");
String user = p.getProperty("hibernate.connection.username");
String password = p.getProperty("hibernate.connection.password");
DriverManager.getConnection(url, user, password).close();
So, simple try-catch can be used. If an exception is caught, connection is dead.
I used this for regular checking of database connection. On application deploy, a TimerTask is scheduled to run every minute. When it catches an exception, it sets a static variable dbAvailable to false (otherwise to true). This variable is being checked on every HTTP client request and if it's true, error 503 is sent back in response.
For scheduling the timer I used ServletContextListener. C3P0 configuration mentioned in the question.

CommunicationsException: Communications link failure

I used java to query some records from Mysql. But in some querys of one duration, i meet a problem which make query failed, but in others , it query successful. The error message is next:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 90 milliseconds ago. The last packet sent successfully to the server was 1,674 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3090)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2979)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3520)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:935)
at com.mysql.jdbc.MysqlIO.nextRow(MysqlIO.java:1433)
at com.mysql.jdbc.MysqlIO.readSingleRowSet(MysqlIO.java:2924)
at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:477)
at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:2619)
at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:1788)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2209)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2619)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2569)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1521)
......
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.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)
Caused by: java.io.IOException: Packets received out of order
at com.mysql.jdbc.MysqlIO.readRemainingMultiPackets(MysqlIO.java:3152)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3077)
... 23 more
I have tried some method, such like:
set max_allowed_packet = 128 * 1024 * 1024 in /etc/my.conf
add ?autoReconnect=true&failOverReadOnly=false&maxReconnects=10 to my connection url
but nothing happens.
My environments is:
Mysql: 5.5.3-m3-log Source distribution
Java: 1.6.0_16
Jdk: HotSpot(TM) 64-Bit Server VM (build 14.2-b01, mixed mode)
JDBC: mysql-connector-java-5.1.18

The problem are solved.
It is because the result is too huge. In my query , i used the default cursor, which is client-side cursors, This means, the whole resultant recordset of a SELECT is returned to the client (application) and the paging is done there. So the total result set is too big and make jdbc client out of memory.
The solution is that:
add "useCursorFetch=true" to JDBC URL configuration parameters
call statement.setFetchSize(100)
You can read more detail from : http://wiki.gxtechnical.com/commwiki/servlet/hwiki?Client%20and%20server%20cursors%20-%20using%20MySQL

This might happen when you try to commit with stale connection. Try checking for the connection state before doing the commit.

Spring 2.5 Could not get JDBC Connection

I'm using spring 2.5 SimpleJdbcTemplate to access MySQL db. When I try to access the DB too often(using Quartz to access it every minute) i get this stack trace:
org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:82)
at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:382)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:458)
at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:466)
at org.springframework.jdbc.core.JdbcTemplate.queryForList(JdbcTemplate.java:497)
at org.springframework.jdbc.core.simple.SimpleJdbcTemplate.queryForList(SimpleJdbcTemplate.java:223)
at com.db.timexis.dao.UserDaoJdbc.getListOfAllUsers(UserDaoJdbc.java:137)
at com.db.timexis.service.AuthServiceImpl.getListOfAllUsers(AuthServiceImpl.java:77)
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.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at $Proxy0.getListOfAllUsers(Unknown Source)
at com.mail.timexis.ReminderBean.execute(ReminderBean.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:276)
at org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean$MethodInvokingJob.executeInternal(MethodInvokingJobDetailFactoryBean.java:260)
at org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:86)
at org.quartz.core.JobRunShell.run(JobRunShell.java:216)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:549)
Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1225)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:880)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:113)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79)
... 30 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2260)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:787)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:49)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:357)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
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)
... 33 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The driver was unable to create a connection due to an inability to establish the client portion of a socket.
This is usually caused by a limit on the number of sockets imposed by the operating system. This limit is usually configurable.
For Unix-based platforms, see the manual page for the 'ulimit' command. Kernel or system reconfiguration may also be required.
For Windows-based platforms, see Microsoft Knowledge Base Article 196271 (Q196271).
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1122)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2181)
... 46 more
Caused by: java.net.BindException: Address already in use: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:519)
at java.net.Socket.connect(Socket.java:469)
at java.net.Socket.<init>(Socket.java:366)
at java.net.Socket.<init>(Socket.java:209)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:293)
... 47 more
The code executed every minute:
public void execute() {
List<User> regularUsers = null;
try {
// get all regular users
ApplicationContext ctx = new ClassPathXmlApplicationContext(
"applicationContext.xml");
AuthService authService = (AuthService) ctx.getBean("authService");
regularUsers = authService.getListOfAllUsers();
} catch (Exception e) {
e.printStackTrace();
}
try {
if (regularUsers != null) {
for (User u : regularUsers) {
if (u.getEmail().matches("^[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*#[A-Za-z0-9-]+(\\.[A-Za-z0-9-]+)*(\\.[_A-Za-z0-9-]+)")) {
mailSender.sendMailReminder(u.getEmail(),
u.getFirstName());
// log mail sending
Date date = Calendar.getInstance().getTime();
SimpleDateFormat sdf = new SimpleDateFormat(
"yyyy/MM/dd HH:mm:ss");
String strDate = sdf.format(date);
System.out.println(strDate + "Reminder mail send...");
// log mail sending
}else{
System.out.println("invalid mail address");
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
It's executed every minute for testing purposes. It will be executed once a week in the future.
My DBCP propertyes:
jdbc.maxActive=15
jdbc.maxIdle=10
jdbc.minIdle=5
jdbc.maxWait=5000
jdbc.validationQuery=select 1
jdbc.timeBetweenEvictionRunsMillis=1000
jdbc.numTestsPerEvictionRun=10
jdbc.minEvictableIdleTimeMillis=1200000
The data base is accessable trough the command line.

Note that you create a new instance of application context each time your method is invoked, and don't close it. It means that resources allocated by beans decalred in this context (for example, connections created by connection pool) are not released.
Typically you need to create application context only once during startup of your application and close it upon shutdown, so I suggest you to implement it this way.
If you actullay need to create a new application context each time you call that method, don't forget to close() it at the end of the method (in finally block for reliability).
Also note that you should declare an appropriate destroy-method for your connection pool bean in order to release resources when context is being closed.

The main exception is "java.net.BindException: Address already in use: connect". It seems you have connection pool leak. Are you sure that every connection is closed after usage? Please check it.

how to solve this issue about InvalidClassException when deserializing objects from inputstream?

I am using james2.3.2 to be my mail server and the backend is mysql 5.5.
I got a exception as the following:
23/06/11 16:39:49 DEBUG mailstore: Exception reading attributes Mail1308818378708-0-to-163.com in spool
java.io.InvalidClassException: [Ljava.lang.StackTraceElement;; enum descriptor has non-zero serialVersionUID: 163864874655243298
at java.io.ObjectStreamClass.readNonProxy(ObjectStreamClass.java:620)
at java.io.ObjectInputStream.readClassDescriptor(ObjectInputStream.java:789)
at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1534)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1466)
at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1591)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1299)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1910)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1834)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at java.util.HashMap.readObject(HashMap.java:1067)
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:592)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:946)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1812)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1719)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.apache.james.mailrepository.JDBCMailRepository.retrieve(JDBCMailRepository.java:846)
at org.apache.james.mailrepository.JDBCSpoolRepository.accept(JDBCSpoolRepository.java:203)
at org.apache.james.mailrepository.JDBCSpoolRepository.accept(JDBCSpoolRepository.java:126)
at org.apache.james.mailrepository.MailStoreSpoolRepository.accept(MailStoreSpoolRepository.java:105)
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:592)
at org.apache.avalon.phoenix.components.application.BlockInvocationHandler.invoke(BlockInvocationHandler.java:134)
at $Proxy5.accept(Unknown Source)
at org.apache.james.transport.JamesSpoolManager.run(JamesSpoolManager.java:299)
at java.lang.Thread.run(Thread.java:595)
How to solve this issue?
Thanks!

I have spent 3 hours on testing with different databases,such as mysql 5.0 and oracle.It workes well on oracle but not on mysql.It seems it's the issue of mysql, not james.