Conference Management System Essay Example for Free

Conference Management System EssayIn Java EE 6, JAX-WS provides the functionality for titanic meshwork serve, which are described in Chapter 19, Building nett go with JAX-WS. Big entanglement attend tos function XML mental objects that follow the Simple Object Access Protocol (SOAP) standard, an XML language defining a message architecture and message initialises. Such systems often double back a machine-readable description of the operations offered by the aid, pen in the Web attends Description Language (WSDL), an XML language for defining interfaces syntactically. The SOAP message format and the WSDL interface definition language harbour gained widespread bankers acceptance. Many development tools, much(prenominal) as NetBeans IDE, displace reduce the complexity of developing meshing service occupations. A SOAP-based design es directialinessiness include the next elements. A formal contract must be established to describe the interface that the clea r service offers. WSDL potty be enjoymentd to describe the details of the contract, which whitethorn include messages, operations, bindings, and the view of the weathervane service. You whitethorn also bear upon SOAP messages in a JAX-WS service without publishing a WSDL. The architecture must address complex nonfunctional conveyments. Many web service specifications address much(prenominal) readments and establish a common vocabulary for them. Examples include transactions, security, addressing, trust, coordination, and so on. The architecture needs to handle asynchronous exhibiting and invocation. In such cases, the infrastructure provided by standards, such as Web Services Reliable Messaging (WSRM), and APIs, such as JAX-WS, with their client-side asynchronous invocation support, can be leveraged out of the box. restful Web ServicesIn Java EE 6, JAX-RS provides the functionality for representational State Transfer ( reposeful) web go. alleviation is well suited for b asic, ad hoc integration scenarios. RESTful web work, often better integrated with HTTP than SOAP-based service are, do non require XML messages or WSDL serviceAPI definitions. Project Jersey is the production-ready reference implementation for the JAX-RS specification. Jersey implements support for the annotations defined in the JAX-RS specification, making it easy for developers to build RESTful web work with Java and the Java Virtual elevator car (JVM). Because RESTful web run use existing well-kn declare W3C and Internet Engineering Task furiousness (IETF) standards (HTTP, XML, URI, MIME) and have a lightweight infrastructure that allows services to be built with minimal tooling, developing RESTful web services is inexpensive and thus has a very low barrier for adoption. You can use a development tool such as NetBeans IDE to further reduce the complexity of developing RESTful web services. A RESTful design may be appropriate when the pursuance conditions are met. The web services are altogether articulateless. A good test is to consider whether the interaction can kick the bucket a re uprise of the server. A caching infrastructure can be leveraged for performance. If the entropy that the web service returns is not dynamically generated and can be cached, the caching infrastructure that web servers and other intermediaries inherently provide can be leveraged to improve performance. However, the developer must take care because such caches are special(a) to the HTTP constitute method for well-nigh servers. The service producer and service immerser have a vernacular dread of the context and content cosmos passed along. Because there is no formal way to describe the web services interface, some(prenominal) parties must fit in out of band on the schemas that describe the data being exchanged and on ways to process it meaningfully. In the real world, most commercial practical applications that expose services as RESTful implementations als o pass out so-called value-added toolkits that describe the interfaces to developers in popular programming languages. Bandwidth is in particular important and needs to be limited. REST is particularly useful for limited-profile devices, such as PDAs and mobile phones, for which the overhead of headers and additional layers of SOAP elements on the XML payload must be restricted. Web service delivery or aggregation into existing web sites can be enabled easily with a RESTful style. Developers can use such technologies as JAX-RS and asynchronous JavaScript with XML (AJAX) and such toolkits as Direct Web Remoting (DWR) to consume the services in their web applications.Rather than starting from scratch, services can be exposed with XML and consumed by HTML pages without significantly refactoring the existing web site architecture. quick developers will be more productive because they are adding to something they are already familiar with rather than having to start from scratch wit h unfermented technology. RESTful web services are discussed in Chapter 20, Building RESTful Web Services with JAX-RS. This chapter contains information about generating the skeleton of a RESTful web service using some(prenominal) NetBeans IDE and the Maven project wariness tool.Deciding Which Type of Web Service to UseBasically, you would want to use RESTful web services for integration over the web and use big web services in enterprise application integration scenarios that have advanced quality of service (QoS) requirements. JAX-WS addresses advanced QoS requirements ordinarily occurring in enterprise computing. When compared to JAX-RS, JAX-WS makes it easier to support the WS-* set of protocols, which provide standards for security and reliability, among other things, and interoperate with other WS-* conforming clients and servers. JAX-RS makes it easier to drop a line web applications that apply some or all of the constraints of the REST style to induce desirable propert ies in the application, such as loose coupling (evolving the server is easier without breaking existing clients), scalability (start small and grow), and architectural ease (use off-the-shelf components, such as proxies or HTTP routers). You would recognize to use JAX-RS for your web application because it is easier for many compositors cases of clients to consume RESTful web services while enabling the server side to evolve and scale. Clients can choose to consume some or all aspects of the service and mash it up with other web-based services.Types of Web servicesYou can host mere(a) Web services without the needing complex setup. In addition, experienced Web service developers can host more complex services by handling the positionment details themselves. Types of Web services include simple and complexSimple Web servicesFor simple Web services, only simple data types (string, int, and other types) are sent or filld as arguments and values that are returned from methods. You must specify the Java class that provides the implementation for the Web service. InfoSphere MDM Server for PIM handles generating any WSDL, and creating any WSDD (Web Services Deployment Descriptor) for the deployment of the service. entangled Web servicesFor more complex Web services, you provide WSDD to configure the ability to send and receive more than simple types. You author and provide the WSDD in the WSDD field in the Web Service Console, or through the WebServicesetWsddDocPath() script operation. IBM InfoSphere Master Data Management Server for ware Information Management uses the WSDD to deploy the defined service instead of using default WSDD for IBM InfoSphere Master Data Management Server for Product Information Management. You must have a good understanding of Web services to author your WSDD. You must also know the Java2WSDL, and WSDL2Java tools in case you break your deployment with the complex Web service.+Big web servicesBig web services are based on SOAP standa rd and often contain a WSDL to describe the interface that the web service offers. The details of the contract may include messages, operations, bindings, and the location of the web service. Big web services includes architecture to address complex non-functional requirements standardised transactions, security, addressing, trust, coordination, and also handles asynchronous processing and invocation. The SOAP message format and the WSDL interface definition language have gained widespread adoption in traditional enterprises. SOAP based Web Services is a great solution when you need, Asynchronous processing Reliability Stateful operations If the application needs contextual information and conversational state management then SOAP 1.2 has the additional specification in the WS* structure to support those things (Security, Transactions, Coordination, etc).RESTful Web ServicesRESTful web services are based on the way how our web works. Our very own world wide web (www) the largest distributed application is based on an architectural style called REST Representational State Transfer. REST is neither a standard nor a protocol. It is just an architectural style like say for example client-server architecture (client-server is neither a standard nor a protocol). Web services followers this architectural style are said to be RESTful Web services. So what is this REST? agree to Roy Fielding who coined this term, Representational State Transfer is intended to evoke an image of how a well-designed Web application behaves Presented with a network of web pages (a virtual state-machine), the user progresses through an application by selecting links (state transitions), resulting in the next page (representing the next state of the application) being transferred to the user and rendered for their use. In the web, everything is identified by resources.When we type a universal resource locator in the browser we are actually pick uping a resource present on the server . A representation of the resource (normally a page) is returned to the user which depicts the state of the application. On clicking any other link, the application transfers state with the new representation of the resource. Hence the name Representational State Transfer. REST-style architecture follows this concept and consists of clients and servers. Clients bulge out begs to servers servers process requests and return appropriate responses.Requests and responses are built around the transfer of representations of resources which are identified by URI (Uniform Resource Identifier). RESTful web services are based on HTTP protocol and its methods mainly PUT, GET, office staff, and DELETE. These web services are better integrated with HTTP than SOAP-based services are, and as such do not require XML SOAP messages or WSDL service definitions. Because RESTful web services use existing well-known standards (HTTP, XML, URI, MIME) and have a lightweight infrastructure that allows serv ices to be built with minimal tooling, developing RESTful web services is inexpensive and thus has a very low barrier for adoption.RESTful Web Service HTTP methodsA RESTful web services is a collection of resources. For example, consider an office has deployed a web services to abide a tendency of employees and to get individual employee data for use with other departments. The web service makes operational a URL to a list of employees resource. For example, a client would use this URL to get the employee list http//www.example.com/myoffice/employeesOn sending a request to that particular URL, the client would receive the following document.1 2234 3235 4236 5237 6 The above document contains the links to get detailed info about each employee. This is a key feature of REST. The client transfers from one state to the next by examining and choosing from among the alternative URLs in the response document. To get individual employee information, the web service makes available a URL to each employee resource. For example, to get employee information whose id is 237, the client may send a request to the following URL http//www.example.com/myoffice/employee/237And the response document containing the employee information may be as follows 1 2 237 3 xyz 4 abc 5 123 ABC St 6 3344.56 7 picWe have seen the use of HTTP GET method to get the information. In the same way, we can use the other HTTP methods like POST, PUT and DELETE. The consistent meaning of these HTTP methods for the URL http//www.example.com/myoffice/employees is as follows, When a HTTP POST request is sent to the above URL with an employee data, the data will be added to the employee list. When a HTTP PUT request is sent to the above URL with a list of employees then the original list will be modified with this employee list. When a HTTP DELETE request is sent to the above URL then the entire list of employees will be blue-pencild. Similarly for the URL http//www.example.com/myoffice/empl oyee/237 the actions may be interpreted as follows, When a HTTP POST request is sent to the above URL, treat the turn to member as a collection in its own right and create a new entry in it. o For example consider a situation where the employee works in a particular department and the URL http//www.example.com/myoffice/dept/A1205 represents the list of employees working in department A1205. So a POST request to this URL with employee data will add an employee data to that particular department. When a HTTP PUT request is sent to the above URL then modify that particular employee with the new request data or create if employee does not exist. When a HTTP DELETE request is sent to the above URL then delete that particular employee. In this REST form of communication, the service producer and service consumer should have a mutual understanding of the context and content (XML) being passed along. Because there is no WSDL to describe the web services interface, both parties must agree on the schemas that describe the data being exchanged and on ways to process it meaningfully. A RESTful design may be appropriate when, The web services are completely stateless. The data that the web service returns is not dynamically generated and can be cached. o The caching infrastructure that web servers provide can be leveraged to improve performance. However, the developer must take care because such caches are limited to HTTP GET method for most servers. The service producer and service consumer have a mutual understanding of the context and content being passed along. Bandwidth is particularly important and needs to be limited. o REST is particularly useful for limited-profile devices, such as PDAs and mobile phones, for which the overhead of headers and additional layers of SOAP elements on the XML payload must be restricted. Web service delivery or aggregation into existing web sites is to be enabled.