[DDLUTILS-29] "Stream is already closed" with Oracle

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0 RC1
• Component/s: Core - Oracle
• Environment: Using oracle10g jdbc client driver with oracle 8i server
• Assignee: Thomas Dudziak
• Reporter: Alexandre Borgoltz
• Created: 12/Oct/05 23:11
• Updated: 04/Jun/07 02:33
• Resolved: 30/Oct/05 02:38

Description

I get a SQLException stating that the "stream is already closed".
It occurs in at org.apache.ddlutils.io.JdbcModelReader.getValueAsString
for the "COLUMN_DEF" column.

Here is the stack trace - as you can see, I am using the ant task, with the sample xml provided on DdlUtils' site.

java.sql.SQLException: Le flux de données est déjà fermé
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:125)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:162)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:227)
at oracle.jdbc.driver.LongAccessor.getBytes(LongAccessor.java:166)
at oracle.jdbc.driver.LongAccessor.getString(LongAccessor.java:207)
at oracle.jdbc.driver.T4CLongAccessor.getString(T4CLongAccessor.java:390)
at oracle.jdbc.driver.OracleResultSetImpl.getString(OracleResultSetImpl.java:355)
at oracle.jdbc.driver.OracleResultSet.getString(OracleResultSet.java:1559)
at org.apache.ddlutils.io.JdbcModelReader.getValueAsString(JdbcModelReader.java:494)
at org.apache.ddlutils.io.JdbcModelReader.getColumnsForTable(JdbcModelReader.java:277)
at org.apache.ddlutils.io.JdbcModelReader.getTables(JdbcModelReader.java:205)
at org.apache.ddlutils.io.JdbcModelReader.getDatabase(JdbcModelReader.java:140)
at org.apache.ddlutils.task.DatabaseToDdlTask.readSchema(DatabaseToDdlTask.java:194)
at org.apache.ddlutils.task.DatabaseToDdlTask.execute(DatabaseToDdlTask.java:214)

I have tested it with 8i, 9i and 10g versions of the client oracle driver - same result.

It highly looks like this is a bug in oracle's drivers management of Long fields.

My tests proved that resultset.getString("COLUMN_DEF") :
+can't be called twice (if .next() is not called obviously)
+always fails for primary fields with 9i- drivers
+fails if called after e.g. .getString("IS_NULLABLE") with 10g drivers
+works OK if called first with 10g drivers

So what I did is modify
JdbcModelReader.getColumnsForTable(DatabaseMetaData, String)
and move the call of
getValueAsString(..., "COLUMN_DEF", ...)
to be the first one called. This works perfectly on my platform now.

I'll attach the corresponding patch