----- Original Message -----
Sent: Monday, September 15, 2003 3:56
PM
Subject: Re: [JAVA3D] Loading shapes from
databases
I see no problems to store geometries in a
DB.
Geometries are usualy big files, so varchar2 my
not fit your needs. DB LONG, CLOB and BLOB my help here.
about what kind of info will be
stored:
The database format LONG is used to store large
strings, but you can store binary data as explained below;
There also CLOB and BLOB DB formats but I never
use it, maybe a skilled DBA can help you.
Using DB LONG fields to store binary
data
================================
(You can use the below routine to store data in
ASCII format too. Just use String.getBytes() to get the byte[] .
)
* put your binary data in array of
bytes
* of course you will implement the toByteArray()
method ;-)
byte[] mydata =
myGeometry.toByteArray()
* create a String from that byte
array
String strGeomData = new
String(mydata);
* finnaly store you String as used in a DB LONG
colum, by using the setAsciiStream, something like this:
PreparedStatement pstmtDst =
connDst.prepareStatement (" insert into GEOM
(id_geom,geom_data)" +
" values (?, ?)");
StringBufferInputStream is = new
StringBufferInputStream(strGeomData);
pstmtDst.setAsciiStream (2, is,
strGeomData.length());
pstmtDst.setInt
(1, geometryID);
pstmtDst.executeUpdate();
* to
read your data, you can do more or less something like
this:
PreparedStatement pstmtSrc =
connSrct.prepareStatement (" Select id_geom, geom_data from GEOM
" +
" where id_geom
= (?)");
pstmtSrc.setInt(1,
geometryID);
ResultSet rset =
pstmtSrc.executeQuery();
String strGeomData =
null;
while (rset.next()) // expecting more than 1
result handle it here by using Vector, hashtable etc
{
BufferedReader bufferedreader = new BufferedReader(new
InputStreamReader(rset.getAsciiStream(2)));
strGeomData = new
String(bufferedreader.readLine());
}
byte[]
myBinaryGeom = strGeomData.getBytes();
// use your binary data as you wish
;-)
===============
TIP ::
You can compress/decompress your binary
data by using java.util.zip.Inflater/java.util.zip.Deflater classes,
respec.
We use it, and the results are very
impressive.
The above code is not 100% bug free. So code
it with care.
Alessandro Borges
"In principle, everything is a byte array
..."
----- Original Message -----
Sent: Monday, September 15, 2003 7:17
AM
Subject: [JAVA3D] Loading shapes from
databases
Hi people,
is anybody working with this? Loading
geometries from databases? Can you give me any information about this?
Recommendations?
Boby
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