Here is the Exception:
rg.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544332. invalid transaction handle (expecting explicit transaction start)
    at org.firebirdsql.jdbc.AbstractPreparedStatement.<init>(AbstractPreparedStatement.java:141)
    at org.firebirdsql.jdbc.FBPreparedStatement.<init>(FBPreparedStatement.java:40)
    at sun.reflect.GeneratedConstructorAccessor3.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at org.firebirdsql.jdbc.FBStatementFactory.createPreparedStatement(FBStatementFactory.java:89)
    at org.firebirdsql.jdbc.AbstractDatabaseMetaData.getStatement(AbstractDatabaseMetaData.java:6222)
    at org.firebirdsql.jdbc.AbstractDatabaseMetaData.doQuery(AbstractDatabaseMetaData.java:6250)
    at org.firebirdsql.jdbc.FBResultSetMetaData.getExtendedFieldInfo(FBResultSetMetaData.java:836)
    at org.firebirdsql.jdbc.FBResultSetMetaData.getExtFieldInfo(FBResultSetMetaData.java:675)
    at org.firebirdsql.jdbc.FBResultSetMetaData.getPrecision(FBResultSetMetaData.java:309)