Integration of objects including Java bytecodes with legacy 3270 applications

Objects including Java bytecodes are embedded in a 3270 datastream structured field. The 3270 datastream structured field, including the objects so embedded, are passed between a primary logical unit and a secondary logical unit that communicate with each other over a network using 3270 datastream architecture. An initialization protocol sends a Read Partition (Query) structured field from the primary logical unit to the secondary logical unit, to query whether the secondary logical unit supports Java. The secondary logical unit sends a Query Reply structured field to the primary logical unit in response to receipt of the Read Partition (Query) from the primary logical unit if the secondary logical unit supports Java. In response to receipt of the Query Reply structured field from the secondary logical unit, the 3270 datastream structured field including embedded objects such as Java bytecodes is passed between the primary logical unit and the secondary logical unit. The objects that are embedded in a 3270 datastream structured field may include Java bytecodes, images and audio. Spanning may be used to send objects that exceed structured field length limits. Accordingly, Java and other objects may be integrated with legacy 3270 applications, without requiring the rewriting of legacy applications, and allowing the use of the highly developed 3270 datastream architecture.