Re: [INTERFACES] JDBC:Using Large Objects - Mailing list pgsql-interfaces
From | Steffen Zimmert |
---|---|
Subject | Re: [INTERFACES] JDBC:Using Large Objects |
Date | |
Msg-id | 3770054C.CCCC323B@crcg.edu Whole thread Raw |
In response to | RE: [INTERFACES] JDBC:Using Large Objects (Peter Mount <petermount@it.maidstone.gov.uk>) |
List | pgsql-interfaces |
Hi, > The large object code has been working for some time now, however not > all of the stream methods work fully. > > The best thing is to look at the blobtest and ImageViewer examples in > the src/interfaces/jdbc/example directory, as they show what methods are > currently supported. I looked at the suggested source files and also compiled them. However, I was not able to run neither Bobtest nor ImageViewer because the same exception messages occured as in my own application. In addition, I wrote also a little application based on the source of blobtest and the exception occurs whenever I try to save a LargeObject. Here's the source: // Load the driver Class.forName("postgresql.Driver"); // Connect to database System.out.println("Connecting to Database URL = " + url); db = DriverManager.getConnection(url, usr, pwd); System.out.println("Connected...Now creating a statement"); stat = db.createStatement(); // Also, get the LargeObjectManager for this connection System.out.println("Gaining access to LargeObjectApi."); lom = ((postgresql.Connection)db).getLargeObjectAPI(); // Now create the large object System.out.println("creating blob"); int oid = lom.create(); System.out.println("Opening "+oid); LargeObject blob = lom.open(oid); // Create a new TestObject System.out.println("Creating a new TestObject..."); TestObject tObject = new TestObject(1); // Convert TestObject to Byte array System.out.println("Converting object to byte array..."); byte[] objBytes = objectToBytes(tObject); System.out.println("Size of byte array: " + objBytes.length); // Writing byte array to blob System.out.println("Writing byte array to blob..."); blob.write(objBytes,0,objBytes.length); ^^^^ The following exception occurs here! Exception caught. java.sql.SQLException: IOError while reading from backend: java.io.IOException: The backend has broken the connection. Possibly the action you have attempted has caused it to close. java.sql.SQLException: IOError while reading from backend: java.io.IOException: The backend has broken the connection. Possibly the action you have attempted has caused it to close. at postgresql.PG_Stream.ReceiveChar(PG_Stream.java:183) atpostgresql.fastpath.Fastpath.fastpath(Compiled Code) at postgresql.fastpath.Fastpath.fastpath(Fastpath.java:185) atpostgresql.largeobject.LargeObject.write(LargeObject.java:147) atpostgresql.PreparedStatement.setBytes(PreparedStatement.java:295) at basic.<init>(basic.java:45) at basic.main(basic.java:107) Are there perhaps any parameters you have to specify during the installation process of the database to explicitly allow the storage of large objects? Any help is welcome because I really don't know what to do now! :-(( -- Best Regards, Steffen Zimmert Steffen Zimmert Fraunhofer Center for Research in Computer Graphics Providence, Rhode Island, USA email: szimmert@crcg.edu
pgsql-interfaces by date: