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Javin Paul

Difference between ConcurrentHashMap and Collections.synchronizedMap and Hashtable in Java - 0 views

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    I just had a java interview and they asked me about difference between ConcurrentHashMap and Collections.Synchronized-map and then again difference between ConcurrentHashMap and Hashtable. I didn't know so I searched the net found this java hashmap tutorial, this site has some really good java hashmap tutorial e..g how hashmap works in java, how concurrentHashmap is different than hashtable etc.
Hendy Irawan

jMock - An Expressive Mock Object Library for Java - 3 views

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    JMock is a library that supports test-driven development1 of Java2 code with mock objects3. Mock objects help you design and test the interactions between the objects in your programs.
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    "JMock is a library that supports test-driven development of Java code with mock objects. Mock objects help you design and test the interactions between the objects in your programs. The jMock library: makes it quick and easy to define mock objects, so you don't break the rhythm of programming. lets you precisely specify the interactions between your objects, reducing the brittleness of your tests. works well with the autocompletion and refactoring features of your IDE plugs into your favourite test framework is easy to extend."
Javin Paul

Java67: Difference between HashSet and TreeSet in Java - 0 views

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    What are differences between HashSet and TreeSet in Java
mahesh 1234

Difference between JDK, JRE and JVM - javatpoint - 0 views

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    Difference between JDK, JRE and JVM. Java Virtual Machine is a specification and implementaion provided by sun microsystem. It is an abstract machine that is used to provide runtime environment for java application or applet.
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    Difference between JDK, JRE and JVM. Java Virtual Machine is a specification and implementaion provided by sun microsystem. It is an abstract machine that is used to provide runtime environment for java application or applet.
Hendy Irawan

Scout/Overview - Eclipsepedia - 0 views

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    The goal of the Eclipse Scout project is making it easy to build distributed enterprise applications based on the Eclipse platform. It consists of a runtime framework providing transparent service communication between the client and backend part and is shipped with a rich set of common user interface components. The user interface is not built for a particular rendering technology but it encapsulates the core functionality into a headless model. GUI factories are available for rendering the client model into a particular target UI platform. SWT and Swing are supported out of the box and an AJAX GUI factory could be easily added. Developing Scout applications is supported by the Scout SDK, a plug-in set built on top of Eclipse PDE and Eclipse JDT. The Scout SDK works directly on the bare Java resources and assists the development task by providing an augmented view on the underlying Java code. Additionally, it comes with a rich set of wizards and operations for modifying the Scout application project just by editing the underlying Java code. There is no meta-data required. Hence a developer can switch between editing resources using Eclipse's standard editors and leveraging the features of Scout SDK at any point in time. Eclipse Scout can be used to create multi-tier client/server applications, standalone client applications or OSGi-based server applications. Basically, there are three main advantages when choosing Scout as your framework for building such applications. First, the Scout runtime is service oriented by design. Almost every functionality is provided as an OSGi service. Every OSGi bundle may make use of them. Second, Scout provides a rich set of UI elements being uncoupled from a particular GUI technology. And third, building distributed client/server applications is as easy as if both parts would run within the same local JVM.
Javin Paul

Class Variable vs Instance Variable in Java - 0 views

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    Quick guide on class, instance and local variable in Java. major difference between all these three variable is there scope and how do you access it. class variable belongs to class, instance belongs to Object and local variable belongs to local code block.
Arup Vidyerthy

Java for OS X 2013-002: How to re-enable the Apple-provided Java SE 6 web plug-in and W... - 0 views

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    Switching between Apple and Oracle Java plugin
Hendy Irawan

disruptor - High Performance Inter-Thread Messaging Library - Google Project Hosting - 0 views

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    "LMAX aims to be the fastest trading platform in the world. Clearly, in order to achieve this we needed to do something special to achieve very low-latency and high-throughput with our Java platform. Performance testing showed that using queues to pass data between stages of the system was introducing latency, so we focused on optimising this area. "
Hendy Irawan

Comparing Vaadin with Icefaces - Wiki - vaadin.com - 0 views

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    Icefaces is an open source Ajax framework for developing RIA for the web. The applications are structured the same way as JSF applications, but with added Ajax features. In this article there will be a short description of the biggest differences between the IT Mill Toolkit 5.2.0 and Icefaces 1.6.2 based development of RIAs.
Hendy Irawan

The Castor Project - 0 views

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    Castor is an Open Source data binding framework for Java[tm]. It's the shortest path between Java objects, XML documents and relational tables. Castor provides Java-to-XML binding, Java-to-SQL persistence, and more.
anonymous

Getting Started with RequestFactory - Google Web Toolkit - Google Code - 0 views

  • Entity Proxies
    • anonymous
       
      Proxy type (on the Client) vs Entity type (on the server)
  • proxy types
  • entity types
  • ...147 more annotations...
  • methods that return service stubs
  • one RequestFactory interface for your application
  • employeeRequest();
  • @Service(Employee.class)
  • extends RequestContext
  • extends RequestFactory
  • service stub
  • RequestFactory service stubs
  • must extend RequestContext
  • The methods in a service stub do not return entities directly
  • return subclasses of com.google.gwt.requestfactory.shared.Request.
  • This allows the methods on the interface to be invoked asynchronously with
  • Request.fire()
  • fire(    new Receiver()
  • onSuccess
  • callers pass an AsyncCallback that implements onSuccess()
  • takes a Receiver which must implement onSuccess()
  • Receiver is an abstract class having a default implementation of onFailure()
  • you can extend Receiver and override onFailure()
  • onViolation()
  • any constraint violations on the server
  • The Request type returned from each method
  • parameterized with the return type of the service method.
  • Methods that have no return value should return type Request<Void>
  • BigDecimal, BigInteger, Boolean, Byte, Enum, Character, Date, Double, Float, Integer, Long, Short, String, Void
  • subclass of EntityProxy
  • List<T> or Set<T>
  • primitive types are not supported
  • methods that operate on an entity itself
  • like persist() and remove()
  • return objects of type InstanceRequest rather than Reques
  • Server Implementations
  • methods defined in an
  • entity's service interface
  • implemented in the class named
  • @Service annotation
  • in these examples, is the entity class
  • service implementations do not directly implement the RequestContext interface
  • server-side implementations use the domain entity types
  • @Entity
  • EntityManager
  • createQuery
  • getResultList();
  • entityManager()
  • createEntityManager()
  • em.persist(this);
  • em.remove(attached
  • em.close();
  • defined in the service's
  • RequestContext interface
  • even though the implementation does not formally implement the interface in Java
  • name and argument list for each method
  • same on client and server
  • Client side methods
  • return Request<T>
  • only T on the server
  • EntityProxy types become the domain entity type on the server
  • Methods that return a Request object in the client interface are implemented as static methods on the entity
  • Methods that operate on a single instance of an entity, like persist() and remove(),
  • eturn an
  • InstanceRequest
  • in the client interface
  • Instance methods do not pass the instance directly, but rather via the
  • using()
  • instance methods must be implemented as non-static methods in the entity type
  • Four special methods are required on all entities
  • as they are used by the RequestFactory servlet:
  • constructor
  • findEntity
  • An entity's getId()
  • is typically auto-generated by the persistence engine (JDO, JPA, Objectify, etc.)
  • "find by ID" method has a special naming convention
  • find()
  • "find" plus the type's simple name
  • On the server
  • getVersion() method is used by RequestFactory to infer if an entity has changed
  • backing store (JDO, JPA, etc.) is responsible for updating the version each time the object is persisted,
  • RequestFactoryServlet sends an UPDATE
  • if an entity changes as
  • Second, the client maintains a version cache of recently seen entities
  • Whenever it sees an entity whose version has changed, it fires
  • UPDATE events on the event bus
  • so that listeners can update the view
  • GWT.create
  • and initialize it with your application's EventBus
  • GWT.create
  • requestFactory.initialize
  • create a new entity on the client
  • EmployeeRequest request
  • EmployeeProxy newEmployee
  • All client-side code should use the EmployeeProxy
  • not the Employee entity itself
  • unlike GWT-RPC, where the same concrete type is used on both client and server
  • RequestFactory
  • designed to be used with an ORM layer like JDO or JPA
  • on the server
  • to build data-oriented (CRUD) apps with an ORM-like interface
  • on the client
  • easy to implement a data access layer
  • structure your server-side code in a data-centric way
  • GWT-RPC, which is service-oriented
  • On the client side, RequestFactory keeps track of objects that have been modified and sends only changes
  • lightweight network payloads
  • solid foundation for automatic batching and caching of requests in the future
  • RequestFactoryServlet
  • RequestFactory uses its own servlet
  • own protocol
  • not designed for general purpose services like GWT-RPC
  • implements its
  • It is designed specifically for implementing a persistence layer on both client and server.
  • In persistence frameworks like JDO and JPA, entities are annotated with
  • client-side representation of an entity
  • known as a
  • DTO (Data Transfer Object)
  • hook used to indicate that an object can be managed by RequestFactory
  • RequestFactory
  • EntityProxy interface
  • automatically populates bean-style properties between entities on the server and the corresponding EntityProxy on the client,
  • send only changes ("deltas") to the server
  • extends EntityProxy
  • interface
  • @ProxyFor
  • reference the server-side entity being represented
  • It is not necessary to represent every property and method from the server-side entity in the EntityProxy
  • EntityProxyId returned by this method is used throughout RequestFactory-related classes
  • while getId() is shown in this example, most client code will want to refer to
  • EntityProxy.stableId() i
  • to represent any type
  • is not required to expose an ID and version
  • often used to represent embedded object types within entities
  • @Embedded
  • Address
  • Address type
  • POJO with no persistence annotations
  • Address is represented as a ValueProxy
  • extends ValueProxy
  • interface
  • extends EntityProxy
  • interface
  • AddressProxy
  • AddressProxy
  • ValueProxy can be used to pass any type to and from the server
  • RequestFactory
  • interface between your client and server code
  • RequestContext interface
  • The server-side service
  • must implement each method
Hendy Irawan

Eclipse/JFace Data Binding - Tutorial - 0 views

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    " This tutorial explains Eclipse JFace Data Binding which can be used to synchronize data between a data model and an user interface. The tutorial uses the properties API which is the recommended way of doing data binding. This tutorial is based on Eclipse 3.6 (Helios) and Java 1.6. "
Hendy Irawan

Chapter 6. HTTP Caching - 0 views

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    HttpClient Cache provides an HTTP/1.1-compliant caching layer to be used with HttpClient--the Java equivalent of a browser cache. The implementation follows the Decorator design pattern, where the CachingHttpClient class is a drop-in replacement for a DefaultHttpClient; requests that can be satisfied entirely from the cache will not result in actual origin requests. Stale cache entries are automatically validated with the origin where possible, using conditional GETs and the If-Modified-Since and/or If-None-Match request headers. HTTP/1.1 caching in general is designed to be semantically transparent; that is, a cache should not change the meaning of the request-response exchange between client and server. As such, it should be safe to drop a CachingHttpClient into an existing compliant client-server relationship. Although the caching module is part of the client from an HTTP protocol point of view, the implementation aims to be compatible with the requirements placed on a transparent caching proxy. Finally, CachingHttpClient includes support the Cache-Control extensions specified by RFC 5861 (stale-if-error and stale-while-revalidate).
Hendy Irawan

Maven - Json-lib::Welcome - 0 views

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    JSON-lib is a java library for transforming beans, maps, collections, java arrays and XML to JSON and back again to beans and DynaBeans. It is based on the work by Douglas Crockford in http://www.json.org/java. The following tables sumarizes the types conversion between java and javascript:
krowddigital

Angular Vs React, which is the best JavaScript Framework? - 1 views

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    Are you unsure which JavaScript is best for your application? Or are you confused between angular Js and js? This article will explain the differences between angular Js and React Js.
krowddigital

Wireframe Vs Mockup Vs Prototype (What is the difference?) - 1 views

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    You can be confused between wireframe, mockup, and prototype, and it is difficult to understand the differences between the three
anonymous

1. Working with Spring Data Repositories - 0 views

  • Typically, your repository interface will extend Repository, CrudRepository or PagingAndSortingRepository. Alternatively, if you do not want to extend Spring Data interfaces, you can also annotate your repository interface with @RepositoryDefinition
  • It allows quick query definition by method names but also custom-tuning of these queries by introducing declared queries as needed.
  • CREATE_IF_NOT_FOUND (default)CREATE_IF_NOT_FOUND combines CREATE and USE_DECLARED_QUERY.
  • ...21 more annotations...
  • the first By acts as delimiter to indicate the start of the actual criteria
  • The mechanism strips the prefixes find…By, read…By, and get…By from the method and starts parsing the rest of it
  • you can define conditions on entity properties and concatenate them with And and Or
  • The introducing clause can contain further expressions such as a Distinct to set a distinct flag
  • List<Person> findByEmailAddressAndLastname(EmailAddress emailAddress, String lastname); // Enables the distinct flag for the query List<Person> findDistinctPeopleByLastnameOrFirstname(String lastname, String firstname); List<Person> findPeopleDistinctByLastnameOrFirstname(String lastname, String firstname); // Enabling ignoring case for an individual property List<Person> findByLastnameIgnoreCase(String lastname); // Enabling ignoring case for all suitable properties List<Person> findByLastnameAndFirstnameAllIgnoreCase(String lastname, String firstname); // Enabling static ORDER BY for a query List<Person> findByLastnameOrderByFirstnameAsc(String lastname); List<Person> findByLastnameOrderByFirstnameDesc(String lastname);
  • You can combine property expressions with AND and OR. You also get support for operators such as Between, LessThan, GreaterThan, Like for the property expressions
  • AllIgnoreCase
  • IgnoreCase
  • The resolution algorithm starts with interpreting the entire part (AddressZipCode) as the property and checks the domain class for a property with that name (uncapitalized). If the algorithm succeeds it uses that property. If not, the algorithm splits up the source at the camel case parts from the right side into a head and a tail and tries to find the corresponding property, in our example, AddressZip and Code.
  • he infrastructure will recognize certain specific types like Pageable and Sort to apply pagination and sorting to your queries dynamically
  • Pageable
  • Sort sort
  • The first method allows you to pass an org.springframework.data.domain.Pageable instance to the query method to dynamically add paging to your statically defined query. Sorting options are handled through the Pageable instance too
  • <repositories base-package="com.acme.repositories" />
  • Spring is instructed to scan com.acme.repositories and all its subpackages for interfaces extending Repository or one of its subinterfaces. For each interface found, the infrastructure registers the persistence technology-specific FactoryBean to create the appropriate proxies that handle invocations of the query methods. Each bean is registered under a bean name that is derived from the interface name, so an interface of UserRepository would be registered under userRepository
  • This postfix defaults to Impl.Example 1.12. Configuration example<repositories base-package="com.acme.repository" /> <repositories base-package="com.acme.repository" repository-impl-postfix="FooBar" />The first configuration example will try to look up a class com.acme.repository.UserRepositoryImpl to act as custom repository implementation, where the second example will try to lookup com.acme.repository.UserRepositoryFoo
  • To exclude an interface that extends Repository from being instantiated as a repository instance, you can either annotate it with @NoRepositoryBean or move it outside of the configured base-package.
  • ]In general, the integration support is enabled by using the @EnableSpringDataWebSupport annotation in your JavaConfig configuration class.
  • @Configuration @EnableWebMvc @EnableSpringDataWebSupport class WebConfiguration { }
  • In case you need multiple Pageables or Sorts to be resolved from the request (for multiple tables, for example) you can use Spring's @Qualifier annotation to distinguish one from another
  • Spring HATEOAS ships with a representation model class PagedResources that allows enrichting the content of a Page instance with the necessary Page metadata as well as links to let the clients easily navigate the pages.
Hendy Irawan

Seam Framework - Faces Module Overview - 0 views

  • integration between JSF and CDI
  • @Inject into JSF system event listeners, converters and validators
Gergely Notpublic

StringBuffer versus String - JavaWorld - 1 views

  • The significant performance difference between these two classes is that StringBuffer is faster than String when performing simple concatenations.
    • Gergely Notpublic
       
      This is not true anymore AFAIK
Rinav G

JavaBlogging » What is serialVersionUID? - 2 views

  • private static final long serialVersionUID = 1L
  • and it is still there even after the program finished. Let’s see if we can read that file once again, this time without creating it first.
  • Now, let’s see what happens, when we change the serialVersionUID value and try to deserialize once again our file. Change the line 2 in the class SerializeMe so that serialVersionUID contains now 2 instead of 1:
  • ...13 more annotations...
  • serialVersionUID = 2L;
  • static final
  • Exception in thread "main" java.io.InvalidClassException:
  • As you can see, this time the deserialization didn’t go well. ObjectInputStream complained about the serialVersionUID being changed.
  • How does he know that it changed? If serialVersinUID is static, then it should not have been serialized in the first place, and there should be no information about the previous value 1 during the deserialization, right? Well, serialVersionUID is an exception to the rule that “static fields don’t get serialized”.
  • Moreover, if there is no serialVersionUID officially declared in the class to be serialized, compiler automatically adds it with a value generated based on the fields declared in the class.
  • The deserialization of that object does not necessarily have to occur exactly after serialization. It can occur after a few months or on a completely different JVM
  • there is a chance that the class declaration has changed between serialization and deserialization.
  • It checks if the data read from the input stream is compatible with the current definition of the class.
  • when the visibility of a field changes, the serialVersionUID changes too.
  • sometimes you just want for some reason to forbid deserialization of old serialized objects,
  • you might tend to write it once for every serializable class ( or have it generated by the IDE ) and forget about it. WRONG !!!
  • If you write it once and don’t take care to update it when necessary, you loose all the merits of serialVersionUID.
  •  
    What is serialVersionUID? What is it Used For???
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