Open Connection Objects

[Puja Agarwal]

Hi All,

I have a small doubt in closing connection objects. If i close the connection objects directly without closing the PreparedStatement and ResultSet object in a method. Will the db connection object be closed or will it become a dangling object waiting for GC to run and claim them.

When i tried sometimes i get the connection object left open and sometimes it get closed. Why does it behaves like this..


hope i make sense


Thanks

[Jeanne Boyarsky]

Puja,
It will usually be closed, but it depends on driver implementation. It is good practice to close all resources yourself though.

[Scott Selikoff]

It's a good practice to always close any database connection you open within a finally block. Leaving connections open is one of the biggest sources of memory leaks in large systems.

[Sunny Jain]

i have one small query :

Suppose i have the following hierarchy of declaration:

Connection Object
PreparedStatement
ResultSet

and following sequence of close :
PreparedStatement.close()
Connection close

i am not closing the resultSet, Can this cause memory leakage in JAVA?

i heard the if I close the preparedStatment, then result set will close automatically. Does this behavior is guaranteed ?

[Jeanne Boyarsky]

Originally posted by Sunny Jain:
i heard the if I close the preparedStatment, then result set will close automatically. Does this behavior is guaranteed ?

Nothing is guaranteed. It depends on the implementation of the driver.

That said, most people have a utility method that closes all the resources. What's the harm in closing the ResultSet in that method too? It's only in one place after all.