Java™ in the Enterprise (From JavaOne conference) n Java™ in the Enterprise n Access to existing systems JDBC™, O/R Mapping n Distributed Java computing (RMI) n Heterogeneous connectivity (JavaIDL) n Enterprise services Java Naming and Directory Interface, Java Management API, Java Message Service n Server platform Servlets, Enterprise JavaBeans™
Java in the Enterprise n Productivity 1. Programming: Power, safety 2. Cost of ownership: Administration, installation 3. Hardware platform independence: NC, PC, server 4. Java Enterprise Platform: "Write Once, Run Anywhere™ n Java Everywhere in 3-Tier Systems 1. Client/Browser 2. Middleware 3. Server
JDBC: Java access to SQL databases n Platform-independence, database-independence JDBC in JDK 1.1 n Multiple styles of JDBC drivers available 100% Pure Java JDBC drivers are best Over 20 already available n Row set manipulation planned
Java Remote Method Invocation (RMI) n Distributed applications written entirely in Java n Enables distributed Java objects to interact n Behavior can move between Java Virtual Machines(VMs) n Distributed polymorphism and garbage collection n In JDK 1.1
CORBA: Common Object Request Broker Architecture n Object management group Over 700 companies n Object Request Broker (ORB) - Client invokes method on server object - ORB middleware transparently handles request Access new or existing applications and servers n Additional services defined based on ORB
OMG CORBA and Java IDL n Object Request Broker (ORB) - Client invokes method on server object - ORB middleware transparently handles request Access new or existing applications and servers n Java IDL API for heterogeneous remote procedure call n Java ORB n IIOP: Standard CORBA network protocol n IDL:Specify object interfaces Generate interface definitions Portable stubs and skeletons
Java Transaction Service n Java API for OMG object transaction service n Ensure transactional interoperability on Java Platform n Targeted at implementers of transaction managers and resource managers; Support transactional standards n Reference spec announced; Collaboration with IBM, Tandem and BEA.
Java Enterprise Services n Java Naming and Directory Interface (JNDI) Unified interface to naming and directory n Java Management API (JMAPI) Standard open interface for network management n Java Message Service New initiative: API and enabling technology for enterprise messaging.
Java Server: services for the web n Servlet API--like applet but for server Java program extending network server n Server Toolkit Constructs for writing services n Java Web Server In beta n Java Application Server Provide back-end services for NCs
Beanstalk n Environment for running service beans n Java API for Transaction Server Manages interaction between service beans and Communications Other service beans Java enterprise services Transaction Server
Network Architecture: HTTP Web Client Browser URL Java Applet Web Server ____ Java Servlets ____ HTML files ____ DB Application Server _____ Programs/ Scripts HTTP (TCP/IP) CGI JDBC Native Driver NSAPI/ ISAPI
TCP/IP Network Architecture Application Layer Telnet, HTTP, FTP, SMTP, SNMP Transport Layer TCP, UDP Network Layer IP Physical Layer Ethernet, X.25, Token Ring, PPP Sending Data Receiving Data
TCP/IP and Networking Terms n Host: An individual machine on a network. Each host on a TCP/IP network has at lease one unique address (IP number). n Hostname: A symbolic name that can be mapped into an IP number. Most host use DNS (Domain Name Service) to do the mapping. n IP number: A unique address for each hosts on the Internet. The IP number is usually referred as the IP address of a host. The number consists of a network part and a host part. IPv4 address is 32-bit long and used to be expressed as four decimal numbers separated by period such as 126.96.36.199 n Packet: A single message sent over a network. Packet usually refers to data at network layer, as the datagram is used to refer to the data at transport layer.
TCP/IP and Networking Terms n Protocol: A set of data formats and messages used to transmit information. n Protocol stack: The set of protocol layers that provides network functionality. Some of the network protocol stack other than TCP/IP are: OSI (Open Systems Interconnection), IBM SNA (System Network Architecture), DecNet, and Novel Netware. n Socket: A communication endpoint. In TCP/IP, a socket usually is identified by a unique pair consists of the source IP address and port number, and destination IP address and port number. n Intranet: A TCP/IP network that connected to the Internet through a firewall.