Some of the parameters support the communication with database or the caching behaviour and others influence the management of connections. Each case is different and you have to bring some experience as well as experiments to the setting right for your application. Here are some links to find more details on JAVA connections.
In general - but this is valid for all languages - the use of prepare statements will typical improve the performance. Yes, it is a bit more overhead for the application but you get the effort back by better responding application. Of course there are also exceptions where a prepare statement is less effective.
Find here a collection of settings that you might want to consider for your application. This is a list of parameter that was valid for this particular application. Here we want to show up the possibilities you have to optimise the performance of your application. It may also happen that you decrease the applications performance having the this parameters. But you should know that you have them.
nonBlockingIO =false link
timeZonePerObject =false link
packetSize =130000 link
closeHandlesByCleaner =false link
transactionalLobs =false link
maxLazyDroppedStatements =100 link
statementCacheSize =500 link
deferredPrepare =true link