How to acces BLOB field in postgres with JAVA ?

Hello? Please help me.
I have some problems using postgres SQL server.
Could you please help me ?

I will brefly explain my situation.

1) I am testing postgress ver 7.1.2

2) I am using
JDK1.3,
pgsql/jdbc/jdbc7.0-1.2.jar,
pgsql/share/java/postgresql.jar

3) I have created a table 'message like below

CREATE TABLE message (
mid int PRIMARY KEY,
message oid
);

4) I have prepared a program to access the table 'message' in JAVA.

ResultSet rs = s.executeStatement("SELECT * FROM message");

// Question ?
// How to access the field 'message' after executing the above statement
?
// As you know the field-type of 'message' is binary large object
type(BLOB).
// I have tested with rs.getBinaryStream(2), rs.getCharacterStream(2),
rs.getBytes(2)
// ,but all of them don't work well.
// Help me !

// If you know about question, please tell me how to read/write data to
BLOB field.