Application Authorization - Expert Oracle and Java Security - page 232

We will assure that we have a connection to appver , which we can use. We test whether appVerConn
is null , a reference to the connection we are using to converse with appver . If it is null , one of two
problems exist: either we haven't connected yet as appver (call getAppConnections() ), or we have
overwritten our connection to appver , so it is no longer available to execute the update,
putAppConnections() . The solution is to always call putAppConnections() , if needed, before getting one of
the connection strings from the list for use in the application.
It is a trivial matter to convert a Java object, as long as it implements Serializable , into a byte array.
However, it does look at bit daunting at first. Drilling down into this code, we write our object into an
ObjectOutputStream , oout . The ObjectOutputStream is tied directly to a ByteArrayOutputStream , baos .
After we write our object, we flush oout and close it, assuring that our entire object is delivered to baos . At
that point, we call the toByteArray() method of baos to get our object out as a byte array.
Listing 10-24. Store Connection Strings List in Oracle, putAppConnections()
public static void putAppConnections(){
OracleCallableStatement stmt = null;
try {
if( null == appVerConn ) {
if( null == conn ) {
System.out.println( "Call getAppConnections to establish " +
"connection to AppVer first, " +
"else can not putAppConnections!" );
} else {
System.out.println( "Connection to AppVer overwritten - " +
"can not putAppConnections!" );
}
return;
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oout = new ObjectOutputStream( baos );
oout.writeObject( appClass ) ;
oout.flush() ;
oout.close() ;
byte[] appClassBytes = baos.toByteArray() ;
baos.close();
baos = new ByteArrayOutputStream();
oout = new ObjectOutputStream( baos );
oout.writeObject( connsHash );
oout.flush();
oout.close();
byte[] connsHashBytes = baos.toByteArray();
baos.close();
stmt = ( OracleCallableStatement )conn.prepareCall(
"{? = call appsec.appsec_public_pkg. f_set_decrypt_conns (?,?)}" );
stmt.registerOutParameter( 1, OracleTypes.VARCHAR );
stmt.setBytes( 2, appClassBytes ) ;
stmt.setBytes( 3, connsHashBytes ) ;
stmt.executeUpdate();