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Re: Storing and Retrieving PDFs in Oracle
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Posted: Aug 30, 2006 10:53 AM
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import java.sql.Connection;
import java.sql.SQLException;
import java.sql.DriverManager;
import java.sql.CallableStatement;
import oracle.sql.BLOB;
// IO Imports
import java.io.Writer;
import java.io.File;
import java.io.FileInputStream;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileNotFoundException;
public class TestBLOB {
// Variable for reading id value.
static String id = null;
// Variable to read the filename
static String fileName = null;
// Create connection object.
static Connection conn = null;
/*
* Default Constuctor that takes no arguments.
*/
public TestBLOB() {
}
/*
* Constuctor that takes in values of id, filename and streaming flag.
*/
public TestBLOB(String idn, String filename, String flag ) {
id = idn;
fileName = filename;
}
public static void main (String args [])
throws SQLException, FileNotFoundException {
TestBLOB testBlob = new TestBLOB(args[0], args[1]);
testBlob.getConnection();
testBlob.callUpdate(id, fileName);
}
}
/*
* Method that gets database connection and returns the same.
*/
public void getConnection() throws SQLException{
// Load Oracle driver.
DriverManager.registerDriver (new oracle.jdbc.OracleDriver());
try {
// Connect to the database.
conn = DriverManager.getConnection
("jdbc:oracle:thin:@lcw2k7:1531:or920",
"vbasaval", "vbasaval");
} catch (SQLException sqlex) {
System.out.println("SQLException while getting db connection: "+sqlex);
if (conn != null) {
conn.close();
}
} catch (Exception ex) {
System.out.println("Exception while getting db connection: "+ex);
if (conn != null) {
conn.close();
}
}
}
/*
* Method that calls update stored procedure on the database. This will use
* the getCLOB method() and oracle.sql.BLOB class to create the CLOB object
* before passing it to the procedure.
*/
public void callUpdate(String id, String filename)
throws SQLException {
CallableStatement cs = null;
BLOB blob = null;
String blobData = null;
try {
// Read the file whose content has to be updated in the BLOB column.
String lineSep = System.getProperty("line.separator");
BufferedReader br = new BufferedReader(new FileReader(filename));
String nextLine = "";
StringBuffer sb = new StringBuffer();
while ((nextLine = br.readLine()) != null) {
sb.append(nextLine);
sb.append(lineSep);
}
// Convert the content to string.
blobData = sb.toString();
// call Stored DB procedure for updating CLOB column.
cs = (CallableStatement)
conn.prepareCall( "begin updateStory(?,?); end;" );
// create the CLOB object
blob = getCLOB(blobData);
// set id
cs.setObject(1, id );
//set clob data
cs.setObject(2, blob );
// Execute callable statement.
cs.execute();
// Close the Statement object
cs.close();
} catch ( SQLException ex ) {
System.out.println("SQLException status : " + ex.getMessage( ) );
} catch ( Exception ex ) {
System.out.println("some exception " + ex.getMessage( ) );
} finally {
try {
// Close Statement
if ( cs != null ) {
cs.close( );
}
// Free BLOB
if ( blob != null ) {
blob.freeTemporary();
}
// Close connection
if (conn !=null) {
conn.close();
}
} catch ( Exception ex ) {
System.out.println("Some exception in callUpdate method of given "
+ "status : " + ex.getMessage( ) );
}
}
}
/*
* This method creates BLOB object using temporary clob and returns the same.
*/
private BLOB getBLOB( String blobData )
throws Exception {
CLOB tempClob = null;
try {
// create a new temporary BLOB
tempBlob = BLOB.createTemporary( conn, true, BLOB.DURATION_SESSION );
// Open the temporary BLOB in readwrite mode to enable writing
tempBlob.open( BLOB.MODE_READWRITE );
// Get the output stream to write
Writer tempBlobWriter = tempBlob.getCharacterOutputStream( );
// Write the data into the temporary BLOB
tempBlobWriter.write( blobData );
// Flush and close the stream
tempBlobWriter.flush( );
tempBlobWriter.close( );
// Close the temporary BLOB
tempBlob.close( );
} catch ( Exception exp ) {
tempBlob.freeTemporary();
System.out.println("Exception thrown in getBLOB method "
+ "of given status : "
+ exp.getMessage( ) );
}
return tempBlob;
}
}
}
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