double Statement.close() (on AIX 5.1) - Mailing list pgsql-jdbc

From Victor Sergienko
Subject double Statement.close() (on AIX 5.1)
Date
Msg-id 985432687.20040224120756@mail.ru
Whole thread Raw
Responses Re: double Statement.close() (on AIX 5.1)  (Dave Cramer <pg@fastcrypt.com>)
Re: double Statement.close() (on AIX 5.1)  (Kris Jurka <books@ejurka.com>)
List pgsql-jdbc
Gentlemen,

I beg your pardon for incomplete problem description.

On AIX 5.1, IBM Java 1.3.1 I'm using pg74jdbc3.jar dated 24.12.03.
We have a flaw in a legacy program: it calls Statement.close() inside
try() and in finally{} - thus, two times.
On doing that, I get:

java.sql.SQLException: Statement has been closed
        at org.postgresql.jdbc2.optional.PooledConnectionImpl$StatementHandler.invoke(
PooledConnectionImpl.java(Compiled Code))
        at $Proxy1.close(Unknown Source)(Compiled Code)
        at SomeUserClass.someMethod(Something.java:1345)

As JDK java.sql.Statement.close() documentation specifies, calling
Statement.close() on already close()d statement should have no effect.
It's the way Oracle and MS SQL drivers behave, but PG driver throws
this exception.

A pity, I cannot reproduce this statement on my working desk on
Windows XP + Sun Java 1.3.1_02. If I get the possibility to debug on
AIX, I can report more precisely.

Looks like it's postgresql\jdbc2\optional\PooledConnectionImpl.java,
lines ~365:

            // All the rest is from the Statement interface
            if (st == null || con.isClosed())
            {
                throw new SQLException("Statement has been closed");
            }
            if (method.getName().equals("close"))
            {
                try {
                    st.close();
                } finally {
                    con = null;
                    st = null;
                    return null;
                }
            }

  As for me, this should look like:

            // All the rest is from the Statement interface
            if (method.getName().equals("close"))
            {
                try {
                    if (st != null && !con.isClosed()) st.close();
                } finally {
                    con = null;
                    st = null;
                    return null;
                }
            }
            if (st == null || con.isClosed())
            {
                throw new SQLException("Statement has been closed");
            }

  My question is: is it a known bug, an intended feature, or an
OS/JDK-specific bug that was not known before? What's wrong with my
suggestion?

Thank you.

--
Best regards,
 Victor Sergienko


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