Re: NullPointer at ResultSet.java:113

From: Barry Lind <barry(at)xythos(dot)com>
To: Hans Deragon <hans(at)deragon(dot)biz>
Cc: "'pgsql-jdbc'" <pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: NullPointer at ResultSet.java:113
Date: 2002-03-27 05:36:32
Message-ID: 3CA15A60.8020803@xythos.com
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Hans,

I have fixed this problem in current sources. next() no longer throws a
null pointer exception in this case. It throws a more specific
SQLException indicating that the ResultSet is closed.

thanks,
--Barry

Hans Deragon wrote:
> Found the problem. I do:
>
> public static void main(String argv[]) throws Exception
> {
> Class.forName("org.postgresql.Driver");
> Connection m_connection =
> DriverManager.getConnection(DATABASEURL, USERNAME, PASSWORD);
>
> ResultSet rs =null;
> {
> Statement st = m_connection.createStatement();
> rs = st.executeQuery("SELECT * FROM stocksymbol");
> st.close(); // <------ Problem!
> }
>
> System.err.println("\nHANS1" + rs);
> rs.beforeFirst();
> System.err.println("\nHANS1b");
> while(rs.next())
> {
> System.err.println("\nHANS2\n");
> }
>
> As you can see, the statement is closed before the ResultSet is used. It
> used to work with old Postgresql drivers, but not the most recent. I
> will simply remove the st.close() statement in my close. I assume that
> there is a finalize() function in the Statement such that the close is
> done automatically when the instance is disposed.
>
> Still, it would be nice if we got a nice exception instead of a
> NullPointer exception. Can someone correct the code to generate such
> exception?
>
> Sorry for the delay for my response. Its a pet project I am working on,
> on spare time.
>
>
> Sincerely,
> Hans Deragon
>
> Dave Cramer wrote:
>
>> Hans,
>>
>> Generally this means that there is nothing in the result set. Can you
>> give me some code which demonstrates this bug?
>>
>> Dave
>>
>> -----Original Message-----
>> From: pgsql-jdbc-owner(at)postgresql(dot)org
>> [mailto:pgsql-jdbc-owner(at)postgresql(dot)org] On Behalf Of Hans Deragon
>> Sent: Saturday, March 09, 2002 6:13 AM
>> To: pgsql-jdbc
>> Subject: [JDBC] NullPointer at ResultSet.java:113
>>
>>
>> Greetings.
>>
>>
>> Upgraded yesterday to the latest pgjdbc2.jar. I am using JDK
>> 1.4.0. My database is postgresql-7.1.3-2. I get:
>>
>> at org.postgresql.jdbc2.ResultSet.next(ResultSet.java:113)
>> at marketmanager.database.StockSymbol.list(StockSymbol.java:93)
>> at
>> marketmanager.datacollection.stocks.YahooCollector.fetchDataFromWeb(Yaho
>> oCollector.java:56)
>> at
>> marketmanager.datacollection.stocks.YahooCollector.fetchData(YahooCollec
>> tor.java:111)
>> at
>> marketmanager.datacollection.FetchData.main(FetchData.java:13)
>>
>> This is a bug for sure. If there is something wrong I am doing, then
>>
>> it should have been caught by an exception and report to me what I was
>> doing wrong. My code works with an older version of the postgresql jdbc
>>
>> driver. And my code is pretty basic.
>>
>> I could not find on the development website the source of this
>> code. Anybody can provide a pointer? May I suggest a direct
>> hyperlink to the code to the development site from the
>> http://jdbc.postgresql.org/?
>>
>>
>> Ciao
>> Hans
>>
>>
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>>
>>
>
>
>
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