passing a blob as parameter on a java method using Oracle JVM

Question

Hey I'm trying to find a way to get this running. I am using the oracle database 10g where I have blobs stored in a table. I want to be able to read out and pass a blob to a java method in my java code. I loaded my java class in my database via loadjava. The table where I store my blobs is set up, too.

This is my java class and the method I'd like to pass a BLOB

import java.lang.*;
import java.sql.*;
import oracle.sql.*;

public class Test
{

  public static void getWidth(BLOB myBlob) throws Exception
  {
    System.out.println(myblob.length());
  }

};

And this is my Java Stored Procedure (Wrapper) in PL/SQL

CREATE OR REPLACE PROCEDURE testmethod (p_blob  IN  BLOB)
AS LANGUAGE JAVA   
NAME 'Test.getWidth(oracle.sql.BLOB)';

It loads the java class into the database and my wrapper compiles and is stored as well.

When I want to run execute testmethod(testphoto.jpg);

it gives me the error: 'testphoto.jpg must be declared'

Any advice to get this running? Thanks for your time.

This is my PL/SQL BLock from my procedure testmethod:

DECLARE  
  P_FILE VARCHAR2(200);  
  P_BLOB BLOB;  
BEGIN  
  P_FILE := NULL;  
  P_BLOB := NULL;  

  TESTMETHOD(  
    P_FILE => P_FILE,  
    P_BLOB => P_BLOB  
  );  
END;

Doug Porter · Accepted Answer · 2011-01-24 15:17:51Z

3

testphoto.jpg is just the name of a file that you want to pass to the method. You need the contents of that file as a blob to be passed into your procedure. You will need code to actually load the file contents into a blob variable or pull it from a table if it is already in the database. Then you will pass that as the second argument to your procedure.

If you wanted to test it, you can create a temp table and load it with some blob data like so:

create table blobtest (filecontents blob);
insert into blobtest values (utl_raw.cast_to_raw('Test Data'));

Then, you can run some pl/sql from sqlplus to pull that data and pass it to your procedure:

declare
  temp blob;
  filename varchar2(200) := 'Test';
begin

  select filecontents
    into temp
    from blobtest;

  testmethod(filename, temp);

end;
/

Of course, if the data was in a table already and you wanted the length of a blob, you could use the dbms_lob function getLength like so:

select dbms_lob.getLength(filecontents) from blobtest;

edited Jan 24, 2011 at 15:17

answered Jan 24, 2011 at 14:52

Doug Porter

7,9174 gold badges42 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

daniel Over a year ago

Unfortunately I got this error: *Cause: An attempt was made to execute a method in a Java class that had not been previously and cannot now be compiled or resolved successfully. *Action: Adjust the call or make the class resolvable.

daniel Over a year ago

what do I have to put in ('Test Data')

Doug Porter Over a year ago

@DannyRe: You don't, that was just a string value I was converting to a blob for a simple test.

daniel Over a year ago

I put all your code into my db, but didnt work. im so frustrated :( I created a directory in my db. Loaded a jpg into my blob table. its the one i want to send into my java method. I appreciate your help!

daniel Over a year ago

Could you help me there? Damn I need it working by tomorrow... :(

|

Collectives™ on Stack Overflow

passing a blob as parameter on a java method using Oracle JVM

1 Answer 1

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related