Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Andreas Leitgeb <avl@logic.at>
Newsgroups: comp.lang.java.programmer
Subject: Re: Testing the functionality of sub classes
Date: Sun, 20 Aug 2017 14:33:13 -0000 (UTC)
Organization: A noiseless patient Spider
Lines: 35
Message-ID: <slrnopj7la.o2q.avl@logic.at>
References: <87fucnh2wu.fsf@munus.decebal.nl> <subclasses-20170819193036@ram.dialup.fu-berlin.de> <87y3qffim5.fsf@munus.decebal.nl> <ona7tq$igi$1@dont-email.me> <87pobrf855.fsf@munus.decebal.nl> <slrnopiu4a.o2q.avl@logic.at> <87ziaue74o.fsf@munus.decebal.nl> <87valie4xz.fsf@munus.decebal.nl> <onc3s5$1ns5$1@gioia.aioe.org>
Reply-To: avl@logic.at
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Injection-Date: Sun, 20 Aug 2017 14:33:13 -0000 (UTC)
Injection-Info: mx02.eternal-september.org; posting-host="cd31f327af7298cb41a335016b661fc8"; logging-data="19323"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/GJ0IK60mh89DlMdGiu1az"
User-Agent: slrn/1.0.2 (Linux)
Cancel-Lock: sha1:I98yzNaGz2fuUBzUEIHa1lw1wFY=
Xref: csiph.com comp.lang.java.programmer:37316

Arne Vajhøj <arne@vajhoej.dk> wrote:
> On 8/20/2017 9:36 AM, Cecil Westerhof wrote:
>> Cecil Westerhof <Cecil@decebal.nl> writes:
>>> Just to satisfy my curiosity I executed (I do not like the formatting,
>>> but that is what Eclipse does):
>>>      try (
>>>              Statement stmt = conn.createStatement();
>>>              ResultSet rsOne = stmt.executeQuery("SELECT 12 AS twelve");
>>>              ResultSet rsTwo = stmt.executeQuery("SELECT 'Hello World!' AS message")
>>>              ) {
>>>          System.out.println(stmt);
>>>          System.out.println(rsOne);
>>>          System.out.println(rsTwo);
>>>      }
>>>
>>> And this gives:
>>>      org.sqlite.jdbc4.JDBC4Statement@685f4c2e
>>>      org.sqlite.jdbc4.JDBC4ResultSet@7daf6ecc
>>>      org.sqlite.jdbc4.JDBC4ResultSet@7daf6ecc
>>>
>>> So yes, it is like you said: the ResultSet is reused. Is also more
>>> logical. I jumped to a conclusion.
>> 
>> With a H2 database I get:
>>      stat0
>>      rs0: null
>>      rs1: org.h2.result.LocalResult@1bc6a36e columns: 1 rows: 1 pos: -1
>
> That is what happens when you try and do unsupported things: you get
> undefined/implementation specific behavior. Bad!

In this particular case the "undefined/implementation specific behavior"
is ResultSet-implementation's toString().  That's why I suggested to use
System.identityHashCode().