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Re: unnecessary code in Oracle example?

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From	markspace <markspace@nospam.nospam>
Newsgroups	comp.lang.java.programmer
Subject	Re: unnecessary code in Oracle example?
Date	Wed, 09 Oct 2013 12:27:29 -0700
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On 10/9/2013 12:08 PM, Jim Janney wrote:
>
> Thanks.  But that looks like a good idiom to avoid.  I prefer
>
>     MyResource r1 = openResource();
>     try {
>        MyResource r2 = openResource2();
>        try {
>          //  do something
>        } finally {
>          r2.close();
>        }
>     } finally {
>       r1.close();
>     }
>
> Not as pretty syntactically, perhaps, but much clearer semantically.
>

I don't like either one.  Why not take advantage of the fact that 
resources are specified to be closed in the opposite order that they are 
declared in a try-with-resources?

The following demonstrates this by closing the named streams in the 
order C-B-A:


package quicktest;

import java.io.IOException;
import java.io.InputStream;

public class TryResourcesTest
{
    public static void main( String[] args ) throws Exception
    {
       try(
           MyTestStream a = new MyTestStream( "A" );
           MyTestStream b = new MyTestStream( "B" );
           MyTestStream c = new MyTestStream( "C" )
       ) {
          System.out.println( a.read()+b.read()+c.read() );
       }
    }
}

class MyTestStream extends InputStream {

    private final String name;

    public MyTestStream( String name )  {
       this.name = name;
    }

    @Override
    public int read() throws IOException  {
       return 42;
    }

    @Override
    public void close() {
       System.out.println( getClass().getSimpleName()+
        ":"+name+" closed." );
    }
}

Thread

unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 10:38 -0600
  Re: unnecessary code in Oracle example? Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2013-10-09 11:19 -0700
    Re: unnecessary code in Oracle example? ram@zedat.fu-berlin.de (Stefan Ram) - 2013-10-09 19:04 +0000
    Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 13:08 -0600
      Re: unnecessary code in Oracle example? markspace <markspace@nospam.nospam> - 2013-10-09 12:27 -0700
        Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 14:21 -0600
          Re: unnecessary code in Oracle example? markspace <markspace@nospam.nospam> - 2013-10-09 14:56 -0700
            Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-09 20:56 -0600
              Re: unnecessary code in Oracle example? Arivald <NOSPAMarivald@interia.pl> - 2013-10-10 06:42 +0200
                Re: unnecessary code in Oracle example? Sebastian <news@seyweiler.dyndns.org> - 2013-10-10 07:47 +0200
                Re: unnecessary code in Oracle example? Arivald <arivald_@AT_interia_DOT_.pl> - 2013-10-10 10:26 +0200
                Re: unnecessary code in Oracle example? Jim Janney <jjanney@shell.xmission.com> - 2013-10-10 08:47 -0600
    Re: unnecessary code in Oracle example? Robert Klemme <shortcutter@googlemail.com> - 2013-10-09 21:11 +0200
      Re: unnecessary code in Oracle example? cuzdav@gmail.com - 2013-10-10 08:49 -0700

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