java barcode reader api open source An Overview of CWM in Java

Generator qr bidimensional barcode in Java An Overview of CWM

From the discussion above, it should be clear that there are really only two important elements in the Internet architecture: Hosts are the endpoints of communications. Network applications run on hosts. Hosts are responsible for maintaining the state involved in their communications with other hosts. Routers are packet switches that route packets between hosts. Routers exchange information about the reachability of hosts but do not maintain any state associated with a speci c host communication. The routers that perform packet forwarding constitute the routing fabric of the Internet. The original IP assumed that the connections between routers and hosts were always available and that the connections had a certain capacity or bandwidth. The bandwidth of the connections was assumed not to be of particular concern to hosts, just to routers that wanted to optimize their packet-forwarding performance. Also, the character of the communication between hosts and routers was assumed to be independent of the underlying link characteristics. As will become apparent later, these assumptions turn out to be largely incorrect for wireless networking.

ible value proposition in any of the 18 markets it targeted. Boo did too much, too fast, and too expensively. Following its crash-and-burn demise in the spring of 2000, a British Internet technology rm bought Boo s back-of ce infrastructure for a mere US$400,000, and fashionmall.com acquired Boo s customer list, content, trademark, and domain names for an undisclosed sum. Even more moderate efforts can run into big troubles. Despite its obvious business model and easily explained value proposition, the United Kingdom s LastMinute had trouble keeping its Italian and Spanish af liates adequately funded. American travel site Travelocity experienced another kind of international problem when it launched its Italian site several years ago. Volatile content in a consumer market forever demanding to be entertained meant that the Italian variant quickly looked less and less like its branded counterpart, both undermining the brand and causing Travelocity eventually to pull the plug and start over. The problem that many companies face as they go international is that they forget two things: (1) It s not enough simply to translate your content, and (2) a successful international business requires making a long-term commitment. Boo had the right idea about what would appeal to buyers in France and Italy, but not the temperance to take a less ambitious bite. Most companies lack Boo s understanding of the challenge, so they start by simply translating their domestic site into French and Italian this quarter, then into German and Dutch next quarter, and they never look back. Without active work on a site to keep it up to date, the experience gets stale, uninteresting, and out of sync with the corporate site. The result is that visitors to a derived site cannot count on the information that they nd; it may be inaccurate, out of date, and inconsistent because of the cobbledtogether processes used by most companies that do have international sites. This can be a disaster as bilingual customers arbitrage the net for the best experience and current information. Even if your prospects in other countries do not speak your home-country language, they can see easily see the difference between an expensively produced headquarters site and a low-rent effort served up in their market. To paraphrase the international strategist at State Street Global Advisors, Don t advertise a work in progress, and don t show something that you yourself wouldn t want to use. Just as you cannot stand still with site content, you must look ahead with regard to technology and design. While the conventional wisdom is that the United States leads the rest of the world in Web technology, the reality is that markets in Scandinavia outpace the United States in certain respects

Positive Test Cases Should Return Expected Responses: Positive test cases should return expected values. For example, a potential customer in Pasadena may want to nd a home in Pasadena. If the realtor has an of ce branch in Pasadena, the customer should receive a response listing the location of this branch. In this instance, a number of different positive test cases should be constructed to ush out any bugs in the web service. The SOAP responses from the web service should be captured and compared with the expected responses. These comparisons should be saved as regression tests. Responses Should be XML Valid and Pass Interoperability Checks: The captured responses should be veri ed by an XML validator. They should also be conformant to WS-I Basic Pro le 1.0. Web Services Should Gracefully Handle Negative Test Cases that Simulate Abnormal and Malicious Uses: Negative test cases can be divided into several categories. The rst set of negative test cases contains transporlevel errors. The web service should be able to handle various HTTP header errors, such as wrong SOAPAction values (when applicable), wrong Content-Types, and wrong Content-Lengths. In each case, the web service should not fail, but instead return appropriate HTTP-level error messages, or ignore the errors and process the XML request. These return values should be captured and compared against expected results. A negative test case is said to succeed when its comparison succeeds. Another set of negative test cases contains XML-level errors. These may involve sending invalid XML or XML with deliberately bad values. In such cases, the expected response is a SOAP fault with a reason for the fault. Feedback from the Test Cases Should be Used to Modify/Fix/Upgrade Elements of the Web Service as Well as the Development Process: By testing the submitRequest() operation with the tool, we were able to nd several problems with our web service. The rst problem was that the server could not deserialize the XML request into the appropriate Java objects. As a result, the web service returned a SOAP fault. This often happens when the Java object does not implement all of the methods that a typical bean object should that is, it does not have all the get and set methods for all of its elds. The obvious x is to change the Java class that is responsible for the problem. However, a further step should be taken so that this problem can be avoided in the future. This

This leads to a fundamental question: when several transitions become firable in the same marking, therefore firable in parallel, how is the next state defined In fact, this choice is called and defined the semantics of parallelism . b) The traditional choice: interleaving Several possibilities exist for defining the next marking, for example: all transitions are fired at the same time; only one transition is fired at a time; a subset of the enabled transitions is fired; all possible subsets of the set of transitions are fired. It is clear that the first and the last cases are extremes, as: in the first one, only one next marking is obtained; in the last one, 2n 1 markings are obtained, one for each subset of the set (each transition, then 2 amongst n, then 3 amongst n, etc). Most importantly, in the second case, each enabled transition will lead to a marking (with n next markings for n enabled transitions). In fact, this second solution provides the usual choice taken for defining the semantics of parallelism: it is called interleaving semantics . In interleaving semantics, the next markings are obtained by considering all the possible firings of all transitions, one after the other, starting from the same state, and leads to n next markings when n transitions are enabled in parallel. This choice is also fully justified for PNs, as we will see later, because: it leads to a small number of next markings, which simplifies the model of behavior; and in spite of this simplification, it provides all possible behaviors. Nevertheless, such a choice still leads to an exponential number of markings for very parallel behaviors, as will be seen later.