RE: getting exception when trying to close connection
I read in the javadoc of the .close() method, that when the garbage collector runs, it
closes the connections.
Well, this isn't working obviously... the thing that's keeping me from solving the
problem is the frequency it happens... I can't understand why a connection can't be
closed... I know of no timeouts set on oracle,and if it had... the connection AND the
socket would be closed, don't u think? And I still have dozens of open INACTIVE
connections on oracle...
A timeout on the Connection obj is also hard to believe... even because when I
debugged it with a page opening 10 connections (just for testing, I don't have such a
page)... 3 of them didn't close... and it was not the last three... just some random
conns...
and I guess when the finalize() method runs, its because there's no use for that
object (in this case the DAO) anymore, right? So what would cause the exception? I'll
try to focus on the booleans, but I don't think it'll help, since everytime I debugged
it, the error is always on the con.close(), meaning the booleans are ok.
I'm hopeless!
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
[EMAIL PROTECTED] 11/06/02 18:17
OK well, a couple answers first. The socket that is being referred to is the
underlying (usually tcp/ip) socket that your driver uses to connect to the
database. A connection is an abstraction from what the implementation socket
is. A couple things could be happening with your oracle driver. First, there
can be an inactive timeout set on your oracle database, where connections
are closed after a timeout period to free up resources. You would get the
same error if for instance the server on the other end lost power, and
therefore closed the connection by being turned off. The other thing is,
your driver could have a timeout set. I haven't used the oracle driver
extensively, so i'm not really sure how you configure it. Look in the docs.
The other thing you want to do is separate out those three boolean
statements so you can determine which one is failing. Checking for null is
not going to throw the exception so pretty much focus on your last two. (and
look at your driver configuration docs) you may want to try this method
instead.
static Connection getConnection(String url, Properties info);
//Attempts to establish a connection to the given database URL.
In properties, you can specify driver settings.
Zak
-Original Message-
From: Christian J. Dechery [ mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 12:03 PM
To: [EMAIL PROTECTED]
Subject: RE: getting exception when trying to close connection
ok... there you go:
public DAOFundos(Esquema esq) {
if( esq==null ) {
esq = esquemaDefault;
}
try {
Class.forName( esq.getDriver() );
con = DriverManager.getConnection(esq.getUrl(), esq.getUser(),
esq.getPassword());
}
catch(ClassNotFoundException cnf) {
System.out.println (Erro: driver nao encontrado! +cnf.getMessage());
}
catch(SQLException sql) {
System.out.println(Erro ao obter conexão! +sql.getMessage() );
}
}
this is the code for the default constructor... in this case the class
Esquema contains info about: drivers, user, url and pwd.
the driver is always oracle.jdbc.driver.OracleDriver
thanks again
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
[EMAIL PROTECTED] 11/06/02 16:03
It would be halpful to see the declaration of con, and the type of driver
you are using
-Original Message-
From: Christian J. Dechery [ mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 11:41 AM
To: [EMAIL PROTECTED]
Subject: getting exception when trying to close connection
I know my implementation isn't the best there is... take a look at this
code:
protected void finalize()
try
if( con!=null !con.isClosed() con.getAutoCommit() )
con.close();
}
}
catch(SQLException sqle)
System.out.println([+this.getClass().getName()+] Não foi possível
fechar a conexão. +sqle.toString()+\n);
// sqle.printStackTrace();
}
}
that's what I use to TRY to close all connections... this code is in my DAO
class. Sometimes I have up to four DAO classes instantiated in a single
JSP... I debugged it... at least one always fails to close giving me this
exception: I/O error: socket closed
what does that mean? what socket? And why did all the other connections
closed and this didn't?
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
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RE: getting exception when trying to close connection
It would be halpful to see the declaration of con, and the type of driver
you are using
-Original Message-
From: Christian J. Dechery [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 11:41 AM
To: [EMAIL PROTECTED]
Subject: getting exception when trying to close connection
I know my implementation isn't the best there is... take a look at this
code:
protected void finalize() {
try {
if( con!=null !con.isClosed() con.getAutoCommit() ) {
con.close();
}
}
catch(SQLException sqle) {
System.out.println([+this.getClass().getName()+] Não foi possível
fechar a conexão. +sqle.toString()+\n);
// sqle.printStackTrace();
}
}
that's what I use to TRY to close all connections... this code is in my DAO
class. Sometimes I have up to four DAO classes instantiated in a single
JSP... I debugged it... at least one always fails to close giving me this
exception: I/O error: socket closed
what does that mean? what socket? And why did all the other connections
closed and this didn't?
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
--
To unsubscribe, e-mail: mailto:[EMAIL PROTECTED]
For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: getting exception when trying to close connection
ok... there you go:
public DAOFundos(Esquema esq) {
if( esq==null ) {
esq = esquemaDefault;
}
try {
Class.forName( esq.getDriver() );
con = DriverManager.getConnection(esq.getUrl(), esq.getUser(),
esq.getPassword());
}
catch(ClassNotFoundException cnf) {
System.out.println (Erro: driver nao encontrado! +cnf.getMessage());
}
catch(SQLException sql) {
System.out.println(Erro ao obter conexão! +sql.getMessage() );
}
}
this is the code for the default constructor... in this case the class Esquema
contains info about: drivers, user, url and pwd.
the driver is always oracle.jdbc.driver.OracleDriver
thanks again
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
[EMAIL PROTECTED] 11/06/02 16:03
It would be halpful to see the declaration of con, and the type of driver
you are using
-Original Message-
From: Christian J. Dechery [ mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 11:41 AM
To: [EMAIL PROTECTED]
Subject: getting exception when trying to close connection
I know my implementation isn't the best there is... take a look at this
code:
protected void finalize() {
try {
if( con!=null !con.isClosed() con.getAutoCommit() ) {
con.close();
}
}
catch(SQLException sqle) {
System.out.println([+this.getClass().getName()+] Não foi possível
fechar a conexão. +sqle.toString()+\n);
// sqle.printStackTrace();
}
}
that's what I use to TRY to close all connections... this code is in my DAO
class. Sometimes I have up to four DAO classes instantiated in a single
JSP... I debugged it... at least one always fails to close giving me this
exception: I/O error: socket closed
what does that mean? what socket? And why did all the other connections
closed and this didn't?
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
--
To unsubscribe, e-mail: mailto:[EMAIL PROTECTED]
For additional commands, e-mail: mailto:[EMAIL PROTECTED]
RE: getting exception when trying to close connection
OK well, a couple answers first. The socket that is being referred to is the
underlying (usually tcp/ip) socket that your driver uses to connect to the
database. A connection is an abstraction from what the implementation socket
is. A couple things could be happening with your oracle driver. First, there
can be an inactive timeout set on your oracle database, where connections
are closed after a timeout period to free up resources. You would get the
same error if for instance the server on the other end lost power, and
therefore closed the connection by being turned off. The other thing is,
your driver could have a timeout set. I haven't used the oracle driver
extensively, so i'm not really sure how you configure it. Look in the docs.
The other thing you want to do is separate out those three boolean
statements so you can determine which one is failing. Checking for null is
not going to throw the exception so pretty much focus on your last two. (and
look at your driver configuration docs) you may want to try this method
instead.
static Connection getConnection(String url, Properties info);
//Attempts to establish a connection to the given database URL.
In properties, you can specify driver settings.
Zak
-Original Message-
From: Christian J. Dechery [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 12:03 PM
To: [EMAIL PROTECTED]
Subject: RE: getting exception when trying to close connection
ok... there you go:
public DAOFundos(Esquema esq) {
if( esq==null ) {
esq = esquemaDefault;
}
try {
Class.forName( esq.getDriver() );
con = DriverManager.getConnection(esq.getUrl(), esq.getUser(),
esq.getPassword());
}
catch(ClassNotFoundException cnf) {
System.out.println (Erro: driver nao encontrado! +cnf.getMessage());
}
catch(SQLException sql) {
System.out.println(Erro ao obter conexão! +sql.getMessage() );
}
}
this is the code for the default constructor... in this case the class
Esquema contains info about: drivers, user, url and pwd.
the driver is always oracle.jdbc.driver.OracleDriver
thanks again
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
[EMAIL PROTECTED] 11/06/02 16:03
It would be halpful to see the declaration of con, and the type of driver
you are using
-Original Message-
From: Christian J. Dechery [ mailto:[EMAIL PROTECTED]]
Sent: Tuesday, June 11, 2002 11:41 AM
To: [EMAIL PROTECTED]
Subject: getting exception when trying to close connection
I know my implementation isn't the best there is... take a look at this
code:
protected void finalize()
try
if( con!=null !con.isClosed() con.getAutoCommit() )
con.close();
}
}
catch(SQLException sqle)
System.out.println([+this.getClass().getName()+] Não foi possível
fechar a conexão. +sqle.toString()+\n);
// sqle.printStackTrace();
}
}
that's what I use to TRY to close all connections... this code is in my DAO
class. Sometimes I have up to four DAO classes instantiated in a single
JSP... I debugged it... at least one always fails to close giving me this
exception: I/O error: socket closed
what does that mean? what socket? And why did all the other connections
closed and this didn't?
.:| Christian J. Dechery
.:| FINEP - Depto. de Sistemas
.:| [EMAIL PROTECTED]
.:| (21) 2555-0332
--
To unsubscribe, e-mail: mailto:[EMAIL PROTECTED]
For additional commands, e-mail:
mailto:[EMAIL PROTECTED]
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For additional commands, e-mail: mailto:[EMAIL PROTECTED]
