Web System error after some time online

I have a web system on a server, I'm using tomcat and the system is working fine, but when it's a while, without someone getting into the system, it stops working. For example I leave the job and leave the system running on the server, when I come back the next day and try to get into the error.

My doubts are as follows: What can this problem be?

Error excerpt in tomcat log:

25-Jun-2015 08:10:38.757 WARN [http-nio-8080-exec-49] org.hibernate.engine.jdbc.spi.SqlExceptionHelper.logExceptions SQL Error: 0, SQLState: 08S01
25-Jun-2015 08:10:38.757 ERROR [http-nio-8080-exec-49] org.hibernate.engine.jdbc.spi.SqlExceptionHelper.logExceptions Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.net.SocketException
MESSAGE: Software caused connection abort: socket write error

STACKTRACE:

java.net.SocketException: Software caused connection abort: socket write error
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(Unknown Source)
    at java.net.SocketOutputStream.write(Unknown Source)
    at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
    at java.io.BufferedOutputStream.flush(Unknown Source)
    at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:2744)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1612)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3283)