Re: NullPointer at ResultSet.java:113

From: Hans Deragon <hans(at)deragon(dot)biz>
To: Dave(at)micro-automation(dot)net
Cc: 'pgsql-jdbc' <pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: NullPointer at ResultSet.java:113
Date: 2002-03-14 23:41:34
Message-ID: 3C91352E.2060908@deragon.biz
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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
>
>
> ---------------------------(end of broadcast)---------------------------
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