RESTful - phrase book

agile –

 

coupling – less coupling between client and server, so server side changes are easier. I think SOAP requires client rebuild.

 

b2b – still dominated by SOAP

 

resource-oriented services –

 

object – each URL logically represents an object, which you can Get (query), POST (create), PUT (update its content) or DELETE

 

entity means ...in ORM lingo

It means an object in memory, backed by a DB record... see [[beginning java EE 7]]

DOM and other components of ajax

[[beginning java ee7]] P372 points out that ajax technology stack includes

• DOM
• xhtml as "final data format" to render the page on browser
• xml or json or plan text as payload

data types in jason

numbers, strings, booleans

 

arrays

 

object – basically associative array of name-value pairs

JPA2 supports stored proc (empty

 

simplest java web server using thread pool

https://github.com/epibook/epibook.github.io/blob/master/solutions/java/concurrency/TaskExecutionWebServer.java Also described in the book [[elements of programming interviews]]

cluster admin server

In Weblogic (perhaps similar elsewhere), a cluster needs an admin server that's not one of the cluster nodes.

 

j4: single point to deploy application, but without admin server, we can have similar convenience?

j4: watch tower to monitor the nodes, but without it, we can monitor them from another place?

j4: single location to store node-configuration

soa AR 4 q&&A

A: corba and dcom. seems like "dist obj" architecture"

A: Traditionally, connections between applications have been tightly coupled, as with CORBA (Common Object Request Broker Architecture). For example, flipping a wall switch to turn on a light is a tightly coupled system. However, making a telephone call to order a book is a loosely coupled system.

A: provider, consumer and a broker, just like JMS. Broker can also be a registry.
provider would PUBLISH its list of services to the registry

A: a Web service is little more than an SOA. However, an SOA doesn't require the use of Web services as we understand them, and some types of Web services can be deployed without an SOA.

Simple SOA block diagram http://www.computerworld.com/computerworld/records/images/story/HowSOAWorks_large.gif

Q: 3 basic roles (processes) for an SOA interaction?

Q: relation to web corba?

Q: relation to web services?

Q: similiar ideas to SOA?

dao-jsp-struts q&&a

q: every browser request would trigger an instantiation of the DAO?
A: i think so, from the DAO factory. In fact, if the request uses 2 tables, then you need 1 DAO intance for each table.

q: at a minimum, how do u keep the dao instance persistent throughout the session?
A: I don't think you want that. If you keep 3000 DAO object in that many sessions, then you need that many connection objects! See also P 360 [[ JSP ]]

q: dao objects are placed in jndi/app/session/request scope?
A: I think you can put in request scope.

[lopri] q: jndi?

q: in a non-trivial system like hib or struts, what are the most basic "interface points" of DAO
- how does a client get a DAO? jndi?
- where does the DAO return result to? in a bean? a value object?
- how does the client receive the result?

core DAO q&&a

q0: every call to the dao creates a new connection?
A0: every DAO instance HAS-A connection object, perhaps from a pool. A connection object is usually open and usable. Before the link is established with the DB, the connection object probably doesn't exist.

q1: methods in the dao object?
get*() like getSomethingByPrimaryKey(int key)
insert*()
special methods? getConnection()?

q2: a single DAO or teacherDAO, departmentDAO, courseDAO, projectDAO.. .?
A2: multiple is more common. Consider CMP.
A2: Even a daoFactory class should be defined for a particular db table like CatalogDAOFactory.getDAO() -- static method

q3: where is sql stored?
a3: a studentDAO would expose many getAge(), setNationality(), updateMatricYear(), insertCourse()... methods. Where do u think the sql is?

q: how is the connection obj created and passed?
a: The connection URL is often harded-coded in the dao (or dao-factory)

[lopri] q: singleton? probably not, we need many instances of DAO

[lopri] q: dao is an iface or ...?
A: We have seen simple cases, where interface is unnecessary.

[lopri] q: dao factory? not always necessary? how about in strusts?