Re: Using bytea with ResultSet.getBytes("..."). Problem. Help!!

On 19-Jul-07, at 12:20 AM, roman wrote:

> Hello!
> (I use Netbeans 5.5, Jdk 1.6, postgreSql 8.1.5 on linux host).
>
>
> I have a problem with reading big binary data from BYTEA field.
> I write to it about 16MB pdf file (as byte[] array) sucessfully,
> but when I try to read it back I have an exception:
>
> Exception occurred during event dispatching:
> java.lang.OutOfMemoryError: Java heap space
> at org.postgresql.util.PGbytea.toBytes(PGbytea.java:53)
> at org.postgresql.jdbc2.AbstractJdbc2ResultSet.getBytes
> (AbstractJdbc2ResultSet.java:2152)
> at
> org.postgresql.jdbc2.AbstractJdbc2ResultSet.getBinaryStream
> (AbstractJdbc2ResultSet.java:2272)
> at
> org.postgresql.jdbc2.AbstractJdbc2ResultSet.getBinaryStream
> (AbstractJdbc2ResultSet.java:2367)
> I have no problem with files about 1MB.
>
The driver has to take it all into memory, so if you don't have
enough memory for the file, you will run out of memory.
>
> My code for writing object:
> ...
> java.sql.PreparedStatement
> insAttachment=connection.prepareStatement("INSERT INTO \"T_Table
> \" (\"f_InitialDocument\") VALUES (?)"); //f_InitialDocument is a
> BYTEA field
> ...
> public void insertAttachment(String FILENAME) {
> byte[] buf=null;
> try {
> //first read file to buf
> java.io.File f=new java.io.File(FILENAME);
> if(f.exists() && f.canRead()) {
> java.io.RandomAccessFile raf=new
> java.io.RandomAccessFile(f, "r");
> buf=new byte[(int)raf.length()];
> raf.readFully(buf);
> raf.close();
> //Write it to database
> insAttachment.setBytes(1, buf);
> insAttachment.execute();
> } else { ret=false; }
> } catch(Exception e) {
> ret=false;
> }
> }
> My code for reading object:
> ...
> String query="SELECT \"f_InitialDocument\" FROM \"T_Attachments
> \"";
> java.sql.ResultSet rs=database.executeFastQuery(query); //My
> function for executing query which gives java.sql.ResultSet
> if(rs!=null) {
> try {
> if(rs.next()) {
> byte[] buf=rs.getBytes("f_InitialDocument"); //
> HERE I GOT THAT EXCEPTION ABOUT OutOfMemory!!!
> //Create a template file
> String filename=database.getTempFilename(); //
> Function for generating temporary filenames basing on GUID
> java.io.File f=new java.io.File(filename);
> if(f.createNewFile()) {
> java.io.FileOutputStream fos=new
> java.io.FileOutputStream(f);
> fos.write(buf);
> fos.close();
> database.executeCommand(filename); //function
> for opening file in appropiate application
> }
> }
> } catch(Exception e){}
> }
> ...
>
> I tried to launch my program with options: -Xmx800M -Xms1500M, but
> it didn't help...
>
> I tried to use: java.io.InputStream is=rs.getBinaryStream
> ("f_InitialDocument"); but got the same error in this string in
> debugger.
>
> How can I read such big objects???
> Please help me.
>
> Roman.
>
>
>
>