Hi,
here is a sample program given in weblogic examples.
Cheers,
Vinod
package examples.jdbc.oracle20;
import java.sql.*;
import java.io.*;
import weblogic.jdbc.common.*;
import weblogic.jdbc20.common.*;
import java.util.Properties;
/**
* This example demonstrates the use of Oracle Blob and Clob datatypes.
* <p>To run this example:
* <ol>
* <li>Set up your development shell as described in <a
* href=http://www.weblogic.com/docs51/techstart/environment.html>Setting up
your environment</a>.
* <p>
* <li> This example also requires the following:
* <ul>
* <li> You must run and compile the example under JDK 1.2.x.
* <li> An Oracle server version 8
* <li> Oracle client libraries version 8.0.5 or later
* </ul>
* <p>
* <li> Change connection parameters to correspond to your Oracle
configuration.
* If you need more help, check the section on connecting
* to a database in the Developers Guide, <a
* href=http://www.weblogic.com/docs51/classdocs/API_joci.html>Using
WebLogic jDriver for Oracle</a>.<p>
*<li>Compile this example by executing the following command in your
development shell:
*
*<p>
*
*<font face="Courier New"><b>$ javac -d %CLIENT_CLASSES%
OracleBlobClob.java</b></font>
*<p>
*
*<li>Run this example by executing the following command in your
development shell:
*
*<p>
*
*<font face="Courier New"><b>$ java
examples.jdbc.oracle20.OracleBlobClob</b></font>
*
*</ol>
* @author Copyright (c) 2000 by BEA Systems, Inc. All Rights Reserved.
*/
public class OracleBlobClob {
public static void main(String argv[])
throws Exception
{
java.sql.Blob myBlob = null;
java.sql.Clob myClob = null;
// get a connection to the Oracle DBMS
// substitute the name of the machine hosting your
// Oracle server for myOracle8Server
Properties props = new Properties();
props.put("user","scott");
props.put("password","tiger");
props.put("server","myOracle8Server");
Driver myDriver = (Driver)
Class.forName("weblogic.jdbc20.oci.Driver").newInstance();
Connection conn = myDriver.connect("jdbc20:weblogic:oracle" , props);
// set Oracle's Auto Commit feature to false.
// This is necessary when manipulating Blobs and Clobs.
conn.setAutoCommit(false);
// ============== Create Table ==================
// Create a table with a Blob and Clob column
try {
// if table does not exist, create it.
Statement crstmt = conn.createStatement();
System.out.println("\nCreating table with Blobs and Clobs...");
crstmt.execute("create table lobtest (id int, blobcol Blob,
clobcol Clob)");
crstmt.close();
}
catch (Exception e) {
System.out.println("Exception: " + e);
System.out.println("Table already exists. Dropping it and
re-creating...");
Statement crstmt2 = conn.createStatement();
crstmt2.execute("drop table lobtest");
crstmt2.execute("create table lobtest (id int, blobcol Blob,
clobcol Clob)");
crstmt2.close();
}
System.out.println("Table created.");
// ============== Initializing blob and clob values ==================
Statement stmt = conn.createStatement();
System.out.println("\nInserting row with blank blob and clob
columns...");
stmt.execute("insert into lobtest values
(44,EMPTY_BLOB(),EMPTY_CLOB())");
System.out.println("Row has been inserted.");
// ============== Manipulating the Blob column ======================
// get a reference to the Blob column
stmt.execute("select * from lobtest where id=44");
ResultSet rs = stmt.getResultSet();
while ( rs.next() ) {
myBlob = rs.getBlob("blobcol");
}
// Create a byte array and store some data in it
System.out.println("\nCreating the following byte array:");
int STREAM_SIZE = 10;
byte[] b = new byte[STREAM_SIZE];
for (int i=0; i < STREAM_SIZE; i++) {
b[i] = (byte)(40 + (i%20)); // range 40-60
System.out.println("byte[" + i + "] = " + b[i]);
}
// Write the byte array to a stream and store it in the Blob column
System.out.println
("\nWriting the byte array to a stream" +
" and storing it in the table as a blob...");
InputStream is = new ByteArrayInputStream(b);
java.io.OutputStream os =
((weblogic.jdbc20.common.OracleBlob)
myBlob).getBinaryOutputStream();
byte[] inBytes = new byte[STREAM_SIZE];
int numBytes = is.read(inBytes);
// write the input stream to the output stream
while (numBytes > 0) {
os.write(inBytes, 0, numBytes);
numBytes = is.read(inBytes);
}
// The flush() method causes the data to be written to the table
os.flush();
// read back the blob
System.out.println("\nReading the blob back from the table and
displaying:");
Statement readblob = conn.createStatement();
readblob.execute("select * from lobtest where id=44");
ResultSet rsreadblob = readblob.getResultSet();
// read the blob into a byte array and display
byte[] r = new byte[STREAM_SIZE];
while ( rsreadblob.next() ) {
Blob myReadBlob = rsreadblob.getBlob("blobcol");
java.io.InputStream readis = myReadBlob.getBinaryStream();
for (int i=0 ; i < STREAM_SIZE ; i++) {
r[i] = (byte) readis.read();
System.out.println("output [" + i + "] = " + r[i]);
}
}
// create some character data to work with
String ss = "abcdefghijklmnopqrstuvwxyz";
System.out.println("\nCreated the following string to be stored as a
clob:\n" +
ss);
// ============== Manipulating the Clob column ======================
// get a reference to the clob column
stmt.execute("select * from lobtest where id=44");
ResultSet crs = stmt.getResultSet();
while ( crs.next() ) {
myClob = crs.getClob("clobcol");
java.io.OutputStream osss =
((weblogic.jdbc20.common.OracleClob)
myClob).getAsciiOutputStream();
byte[] bss = ss.getBytes("ASCII");
osss.write(bss);
osss.flush();
}
conn.commit();
// read back the clob
System.out.println("\nReading the clob back from the table and
displaying:");
Statement readclob = conn.createStatement();
readclob.execute("select * from lobtest where id=44");
ResultSet rsreadclob = readclob.getResultSet();
// read the clob in as and ASCII stream, write to a character array,
and display
while ( rsreadclob.next() ) {
Clob myReadClob =rsreadclob.getClob("clobcol");
java.io.InputStream readClobis = myReadClob.getAsciiStream();
char[] c = new char[26];
for (int i=0 ; i < 26 ; i++) {
c[i] = (char) readClobis.read();
System.out.println("output [" + i + "] = " + c[i]);
}
}
// Drop the table and clean up connections
System.out.println("\nDropping table...");
Statement dropstmt = conn.createStatement();
dropstmt.execute("drop table lobtest");
System.out.println("Table dropped.");
conn.close();
/*
}
catch (Exception e) {// the catch was NamingException;
// a failure occurred
System.out.println("catching naming exception"+ e);
}
finally {
try {
ctx.close();
System.out.println("finally try");
}
catch (Exception e) {
// a failure occurred
System.out.println("finally try catch exception" + e);
}
}
*/
}
}
-----Original Message-----
From: Ritu Kamboj [mailto:[EMAIL PROTECTED]]
Sent: Monday, August 21, 2000 2:18 PM
To: [EMAIL PROTECTED]
Subject: how to fetch blobs from the oracle database using java.
Hi All,
i have created a table in my database as
create table a
( name blob,
id number);
and i have stored some images in the blob column, and their corresponding
id's
can anybody tell me how i should go about retrieving these images from the
database and
display them !!
Thanks
Ritu
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