Re: change ISO8859-1 to GB2312

From:
Lew <noone@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 19 May 2010 12:50:50 -0400
Message-ID:
<ht14tb$7fd$1@news.albasani.net>
On 05/19/2010 02:40 AM, moonhkt wrote:

Our database codepage is iso8859-1. Some data input with GB2312 data.
When export data to iso8859-1 format with GB2312 data, Is it possible
to change iso8859-1 to GB2312 format ?

Machine AIX.

I try below coding not work.

import java.nio.charset.Charset ;
import java.io.*;
import java.lang.String;
public class read_iso {


You should follow the Java naming conventions.

public static void main(String[] args) {
File aFile = new File("abc.txt");
try {


.... and indentation conventions.

     String str = "";


And not initialize to values that are never used, only discarded.

     BufferedReader in = new BufferedReader(
         new InputStreamReader(new FileInputStream(aFile),
"iso8859-1"));

    while (( str = in.readLine()) != null )
    {
        System.out.println(str);
        System.out.println(new String (str.getBytes("iso8859-1")));


Didn't you say the data was input in GB2312 encoding?

Whatever, this constructs a string using the platform native encoding from
bytes encoded using ISO-8859-1. If that isn't the native encoding, you got
worries.

        System.out.println(new String
(str.getBytes("iso-8859-1"),"GB2312")); /* not */


Now you're decoding bytes using GB2312 from bytes encoded using ISO-8859-1.
That can't work.

System.out always uses the platform default string encoding.

    }
} catch (UnsupportedEncodingException e) {
} catch (IOException e) {
}


Don't silently eat exceptions.

}
}


My approach to the encoding would be a lot more straightforward. None of this
wacky "new String()" stuff.

<sscce source="eegee/FooCoder.java">
  package eegee;

  import java.io.*;
  import org.apache.log4j.Logger;
  import static org.apache.log4j.Logger.getLogger;

  public class FooCoder
  {
    private transient final Logger logger = getLogger( FooCoder.class );

    public static void main( String[] args )
    {
     new FooCoder().recode();
    }

    public void recode()
    {
     final BufferedReader rin;
     final BufferedWriter owt;
     try
     {
       rin = new BufferedReader( new InputStreamReader(
         getClass().getResourceAsStream( "temp.txt" ),
         "ISO-8859-1" ));
       owt = new BufferedWriter( new OutputStreamWriter(
         System.out, "GB2312" ));
     }
     catch ( IOException exc )
     {
       logger.error( exc );
       return;
     }
     try
     {
       for ( String str; (str = rin.readLine()) != null; )
       {
         owt.write( str );
         owt.newLine();
       }
       owt.flush();
     }
     catch ( IOException exc )
     {
       logger.error( exc );
     }
     finally
     {
       try
       {
         rin.close();
         owt.close();
       }
       catch ( IOException exc )
       {
         logger.error( exc );
       }
     }
  }
}
</sscce>

--
Lew

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