patch for character set encoding detection for JDBC

Started by Barry Lindover 25 years ago2 messagespatches

barry@xythos.com

over 25 years ago

In looking at the 7.1beta1 code for JDBC, I noticed that support was
added to support character set encodings. However I noticed that the
encoding that is used isn't obtained from the DB. Since Java uses
unicode UCS2 internally the character set encoding is used to translate
strings from/to the DB encoding. So it seems logical that the code
would get the encoding from the DB instead of the current method of
requiring the user pass it as a parameter.

Attached is a patch that gets the DB encoding from the DB in the same
manner as is done in libpq/fe-connect.c. The patch is created off of
the latest CVS sources (Connection.java version 1.10).

thanks,
--Barry

Bruce Momjian

bruce@momjian.us

over 25 years ago

In reply to: Barry Lind (#1)

Re: [PATCHES] patch for character set encoding detection for JDBC

Thanks. Applied.

*** ./Connection.java.orig	Thu Dec 21 18:20:36 2000
--- ./Connection.java	Thu Dec 21 18:21:49 2000
***************
*** 125,132 ****
      PG_HOST = host;
      PG_STATUS = CONNECTION_BAD;

-     encoding = info.getProperty("charSet");  // could be null
-     
      // Now make the initial connection
      try
        {
--- 125,130 ----
***************
*** 265,274 ****
        // This may cause some clients to break when they assume anything other than ISO,
        // but then - they should be using the proper methods ;-)
        //
        //
        firstWarning = null;

! ExecSQL("set datestyle to 'ISO'");

        // Initialise object handling
        initObjectTypes();
--- 263,346 ----
        // This may cause some clients to break when they assume anything other than ISO,
        // but then - they should be using the proper methods ;-)
        //
+       // We also ask the DB for certain properties (i.e. DatabaseEncoding at this time)
        //
        firstWarning = null;

! java.sql.ResultSet initrset = ExecSQL("set datestyle to 'ISO'; select getdatabaseencoding()");
!
! String dbEncoding = null;
! //retrieve DB properties
! if(initrset.next()) {
!
! //handle DatabaseEncoding
! dbEncoding = initrset.getString(1);
! //convert from the PostgreSQL name to the Java name
! if (dbEncoding.equals("SQL_ASCII")) {
! dbEncoding = "ASCII";
! } else if (dbEncoding.equals("UNICODE")) {
! dbEncoding = "UTF8";
! } else if (dbEncoding.equals("LATIN1")) {
! dbEncoding = "ISO8859_1";
! } else if (dbEncoding.equals("LATIN2")) {
! dbEncoding = "ISO8859_2";
! } else if (dbEncoding.equals("LATIN3")) {
! dbEncoding = "ISO8859_3";
! } else if (dbEncoding.equals("LATIN4")) {
! dbEncoding = "ISO8859_4";
! } else if (dbEncoding.equals("LATIN5")) {
! dbEncoding = "ISO8859_5";
! } else if (dbEncoding.equals("LATIN6")) {
! dbEncoding = "ISO8859_6";
! } else if (dbEncoding.equals("LATIN7")) {
! dbEncoding = "ISO8859_7";
! } else if (dbEncoding.equals("LATIN8")) {
! dbEncoding = "ISO8859_8";
! } else if (dbEncoding.equals("LATIN9")) {
! dbEncoding = "ISO8859_9";
! } else if (dbEncoding.equals("EUC_JP")) {
! dbEncoding = "EUC_JP";
! } else if (dbEncoding.equals("EUC_CN")) {
! dbEncoding = "EUC_CN";
! } else if (dbEncoding.equals("EUC_KR")) {
! dbEncoding = "EUC_KR";
! } else if (dbEncoding.equals("EUC_TW")) {
! dbEncoding = "EUC_TW";
! } else if (dbEncoding.equals("KOI8")) {
! dbEncoding = "KOI8_R";
! } else if (dbEncoding.equals("WIN")) {
! dbEncoding = "Cp1252";
! } else {
! dbEncoding = null;
! }
! }
!
!
! //Set the encoding for this connection
! //Since the encoding could be specified or obtained from the DB we use the
! //following order:
! // 1. passed as a property
! // 2. value from DB if supported by current JVM
! // 3. default for JVM (leave encoding null)
! String passedEncoding = info.getProperty("charSet"); // could be null
!
! if (passedEncoding != null) {
! encoding = passedEncoding;
! } else {
! if (dbEncoding != null) {
! //test DB encoding
! try {
! "TEST".getBytes(dbEncoding);
! //no error the encoding is supported by the current JVM
! encoding = dbEncoding;
! } catch (UnsupportedEncodingException uee) {
! //dbEncoding is not supported by the current JVM
! encoding = null;
! }
! } else {
! encoding = null;
! }
! }

// Initialise object handling
initObjectTypes();
[ Charset UTF-8 unsupported, skipping... ]

[ Charset UTF-8 unsupported, skipping... ]

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

patch for character set encoding detection for JDBC

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