Author: saqibkhan
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Creating a MAC
MAC (Message Authentication Code) algorithm is a symmetric key cryptographic technique to provide message authentication. For establishing MAC process, the sender and receiver share a symmetric key K. Essentially, a MAC is an encrypted checksum generated on the underlying message that is sent along with a message to ensure message authentication. The process of using MAC for…
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Message Digest
Hash functions are extremely useful and appear in almost all information security applications. A hash function is a mathematical function that converts a numerical input value into another compressed numerical value. The input to the hash function is of arbitrary length but output is always of fixed length. Values returned by a hash function are…
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Introduction
Cryptography is the art and science of making a cryptosystem that is capable of providing information security. Cryptography deals with the actual securing of digital data. It refers to the design of mechanisms based on mathematical algorithms that provide fundamental information security services. You can think of cryptography as the establishment of a large toolkit…
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Transfer Object Pattern
The Transfer Object pattern is used when we want to pass data with multiple attributes in one shot from client to server. Transfer object is also known as Value Object. Transfer Object is a simple POJO class having getter/setter methods and is serializable so that it can be transferred over the network. It does not…
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Service Locator Pattern
The service locator design pattern is used when we want to locate various services using JNDI lookup. Considering high cost of looking up JNDI for a service, Service Locator pattern makes use of caching technique. For the first time a service is required, Service Locator looks up in JNDI and caches the service object. Further…
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Intercepting Filter Pattern
The intercepting filter design pattern is used when we want to do some pre-processing / post-processing with request or response of the application. Filters are defined and applied on the request before passing the request to actual target application. Filters can do the authentication/ authorization/ logging or tracking of request and then pass the requests…
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Front Controller Pattern
The front controller design pattern is used to provide a centralized request handling mechanism so that all requests will be handled by a single handler. This handler can do the authentication/ authorization/ logging or tracking of request and then pass the requests to corresponding handlers. Following are the entities of this type of design pattern.…
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Data Access Object Pattern
Data Access Object Pattern or DAO pattern is used to separate low level data accessing API or operations from high level business services. Following are the participants in Data Access Object Pattern. Implementation We are going to create a Student object acting as a Model or Value Object.StudentDao is Data Access Object Interface.StudentDaoImpl is concrete class implementing Data Access…
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Composite Entity Pattern
Composite Entity pattern is used in EJB persistence mechanism. A Composite entity is an EJB entity bean which represents a graph of objects. When a composite entity is updated, internally dependent objects beans get updated automatically as being managed by EJB entity bean. Following are the participants in Composite Entity Bean. Implementation We are going…
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Business Delegate Pattern
Business Delegate Pattern is used to decouple presentation tier and business tier. It is basically use to reduce communication or remote lookup functionality to business tier code in presentation tier code. In business tier we have following entities. Implementation We are going to create a Client, BusinessDelegate, BusinessService, LookUpService, JMSService and EJBService representing various entities of Business Delegate patterns. BusinessDelegatePatternDemo, our demo class,…