DB Pool Connection Issue

hi experts,

I'm using
 
DB Class
..
static public Connection getConnection() ..{
        try {
            Context env = (Context) new InitialContext().lookup("java:comp/env");
            DataSource ds = (DataSource) env.lookup("aacc");
            return  ds.getConnection();
        }
catch {}
}

In my JSPs:
...
try {
Connection conn = DBClass.getConnection();
...
}
catch { ..}
finally {
                if (conn != null) try { conn.close(); }
            }

But still I see soo many connections opened in DB tool. Technically all connection will be closed. I was told still they r dozens of connections opened ? Any Idea why ? I double checked all JSPs all has closed connection in finally block.

thx,
PH
princehyderabadAsked:
Who is Participating?
 
Weiping DuConnect With a Mentor Senior Web DeveloperCommented:
when using dataSource, getConnection() gets an already open connection from the pool, and close() simply releases the connection object back to the pool.
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Weiping DuSenior Web DeveloperCommented:
This page explains the connection difference between DataSource (JDBC 2.0) and DriverManager (JDBC 1.0) using figures in detail.

http://www.javaworld.com/javaworld/jw-10-2000/jw-1027-pool.html
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Ajay-SinghCommented:
> But still I see soo many connections opened in DB tool. Technically
> all connection will be closed. I was told still they r dozens of
> connections opened ? Any Idea why ? I double checked all JSPs all has
> closed connection in finally block.

because connection pool is used. The connection you get from datasource is wrapper over actual connection. When this connection is closed - the connection is returned back to pool.
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princehyderabadAuthor Commented:
So does it means its okay to have dozens of connection opened. It will not caused any DB delay or so..... as I hv used connection close in all of my JSPs.
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Weiping DuSenior Web DeveloperCommented:
Yes,  at startup, A pool manager creates the connection objects upfront and optimizes resource usage by dynamically altering the pool size. The benefit to use pool connection is connect to DB without causing overheads on the database resource manager. The connections aren't closed until your application is closed.
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princehyderabadAuthor Commented:
thx Owenli27 !

But still why is that even after all my JSPs have closed connection stmt, still it shows dozens of connection opened ?
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Ajay-SinghConnect With a Mentor Commented:
> But still why is that even after all my JSPs have closed connection
> stmt, still it shows dozens of connection opened ?

because pool never closes the connection. Is no of open connections growing beyound the configured limit of pool
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Weiping DuSenior Web DeveloperCommented:
When you are directly creating a connection by calling Drivermanager.getConnection(..) , you are creating a connection by yourself and when you call close() on it, the link to database is lost.

But when you get a connection from a Datasource, when you call the close() on it, it will NOT close the link to database, it only return to a connection pool where it can be reused by some other classes.
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