Attached is a revised patch that removes the static SimpleDateFormat

objects that Thomas pointed out might be a problem.

PPS.  I have included and updated the comments from the original patch
request to reflect the changes made in this revised patch.

> Attached is a set of patches for a couple of bugs dealing with
> timestamps in JDBC.
>
> Bug#1) Incorrect timestamp stored in DB if client timezone different
> than DB.
> The buggy implementation of setTimestamp() in PreparedStatement simply
> used the toString() method of the java.sql.Timestamp object to convert
> to a string to send to the database.  The format of this is yyyy-MM-dd
> hh:mm:ss.SSS which doesn't include any timezone information.  Therefore
> the DB assumes its timezone since none is specified.  That is OK if the
> timezone of the client and server are the same, however if they are
> different the wrong timestamp is received by the server.  For example if
> the client is running in timezone GMT and wants to send the timestamp
> for noon to a server running in PST (GMT-8 hours), then the server will
> receive 2000-01-12 12:00:00.0 and interprete it as 2000-01-12
> 12:00:00-08 which is 2000-01-12 04:00:00 in GMT.  The fix is to send a
> format to the server that includes the timezone offset.  For simplicity
> sake the fix uses a SimpleDateFormat object with its timezone set to GMT
> so that '+00' can be used as the timezone for postgresql.  This is done
> as SimpleDateFormat doesn't support formating timezones in the way
> postgresql expects.
>
> Bug#2) Incorrect handling of partial seconds in getting timestamps from
> the DB
>
> When the SimpleDateFormat object parses a string with a format like
> yyyy-MM-dd hh:mm:ss.SS it expects the fractional seconds to be three
> decimal places (time precision in java is miliseconds = three decimal
> places).  This seems like a bug in java to me, but it is unlikely to be
> fixed anytime soon, so the postgresql code needed modification to
> support the java behaviour.  So for example a string of '2000-01-12
> 12:00:00.12-08' coming from the database was being converted to a
> timestamp object with a value of 2000-01-12 12:00:00.012GMT-08:00.  The
> fix was to check for a '.' in the string and if one is found append on
> an extra zero to the fractional seconds part.
>
>
> I also did some cleanup in ResultSet.getTimestamp().  This method has
> had multiple patches applied some of which resulted in code that was no
> longer needed.  For example the ISO timestamp format that postgresql
> uses specifies the timezone as an offset like '-08'.  Code was added at
> one point to convert the postgresql format to the java one which is
> GMT-08:00, however the old code was left around which did nothing.  So
> there was code that looked for yyyy-MM-dd hh:mm:sszzzzzzzzz and
> yyyy-MM-dd hh:mm:sszzz.  This second format would never be encountered
> because zzz (i.e. -08) would be converted into the former (also note
> that the SimpleDateFormat object treats zzzzzzzzz and zzz the same, the
> number of z's does not matter).
>
>
> There was another problem/fix mentioned on the email lists today by
> mcannon@internet.com which is also fixed by this patch:
>
> Bug#3) Fractional seconds lost when getting timestamp from the DB
> A patch by Jan Thomea handled the case of yyyy-MM-dd hh:mm:sszzzzzzzzz
> but not the fractional seconds version yyyy-MM-dd hh:mm:ss.SSzzzzzzzzz.
> The code is fixed to handle this case as well.

Barry Lind

1 files changed, 38 insertions, 24 deletions

diff --git a/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java b/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
index 76df78c248..59aef99ad5 100644
--- a/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
+++ b/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
@@ -468,33 +468,46 @@ public class ResultSet extends org.postgresql.ResultSet implements java.sql.Resu
     if(s==null)
 	return null;
 
-    // This works, but it's commented out because Michael Stephenson's
-    // solution is better still:
-    //SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
-// Modification by Jan Thomae
-    String sub = s.substring(s.length() - 3, s.length()-2);
-    if (sub.equals("+") || sub.equals("-")) {
-            s = s.substring(0, s.length()-3) + "GMT"+ s.substring(s.length()-3, s.length())+":00";
-    }
-// -------
-       // Michael Stephenson's solution:
+    boolean subsecond;
+    //if string contains a '.' we have fractional seconds
+    if (s.indexOf('.') == -1) {
+      subsecond = false;
+    } else {
+      subsecond = true;
+    }
+
+    //here we are modifying the string from ISO format to a format java can understand
+    //java expects timezone info as 'GMT-08:00' instead of '-08' in postgres ISO format
+    //and java expects three digits if fractional seconds are present instead of two for postgres
+    //so this code strips off timezone info and adds on the GMT+/-...
+    //as well as adds a third digit for partial seconds if necessary
+    StringBuffer strBuf = new StringBuffer(s);
+    char sub = strBuf.charAt(strBuf.length()-3);
+    if (sub == '+' || sub == '-') {
+      strBuf.setLength(strBuf.length()-3);
+      if (subsecond)  {
+        strBuf = strBuf.append('0').append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
+      } else {
+        strBuf = strBuf.append("GMT").append(s.substring(s.length()-3, s.length())).append(":00");
+      }
+    } else if (subsecond) {
+      strBuf = strBuf.append('0');
+    }
+
+    s = strBuf.toString();
+
     SimpleDateFormat df = null;
 
-// Modification by Jan Thomae
-    if (s.length()>27) {
-    df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
-    } else
-// -------
-    if (s.length()>21 && s.indexOf('.') != -1) {
-	df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSzzz");
-    } else if (s.length()>19 && s.indexOf('.') == -1) {
-	df = new SimpleDateFormat("yyyy-MM-dd HH:MM:sszzz");
-    } else if (s.length()>19 && s.indexOf('.') != -1) {
-	df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss.SS");
-    } else if (s.length()>10 && s.length()<=18) {
-	df = new SimpleDateFormat("yyyy-MM-dd HH:MM:ss");
+    if (s.length()>23 && subsecond) {
+      df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSzzzzzzzzz");
+    } else if (s.length()>23 && !subsecond) {
+      df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
+    } else if (s.length()>10 && subsecond) {
+      df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
+    } else if (s.length()>10 && !subsecond) {
+      df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
     } else {
-	df = new SimpleDateFormat("yyyy-MM-dd");
+      df = new SimpleDateFormat("yyyy-MM-dd");
     }
 
     try {
@@ -504,6 +517,7 @@ public class ResultSet extends org.postgresql.ResultSet implements java.sql.Resu
     }
   }
 
+
   /**
    * A column value can be retrieved as a stream of ASCII characters
    * and then read in chunks from the stream.  This method is