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Hendy Irawan

Getting started with Spring Data JPA | SpringSource Team Blog - 0 views

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    As we have just released the first milestone of the Spring Data JPA project I'd like to give you a quick introduction into its features. As you probably know, the Spring framework provides support to build a JPA based data access layer. So what does Spring Data JPA add to this base support? To answer that question I'd like to start with the data access components for a sample domain implemented using plain JPA + Spring and point out areas that leave room for improvement. After we've done that I will refactor the implementations to use the Spring Data JPA features to address these problem areas. The sample project as well as a step by step guide of the refactoring steps can be found on Github.
Hendy Irawan

Sapphire - 0 views

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    Sapphire - develop UI without wiring individual widgets Little has changed in the way Java desktop UI is written since the original Java release. Technologies have changed (AWT, Swing, SWT, etc.), but fundamentals remain the same. The developer must choose which widgets to use, how to lay those widgets out, how to store the data being edited and how to synchronize the model with the UI. Even the best developers fall into traps of having UI components talk directly to other UI components rather than through the model. Inordinate amount of time is spent debugging layout and data-binding issues. Sapphire aims to raise UI writing to a higher level of abstraction. The core premise is that the basic building block of UI should not be a widget (text box, label, button, etc.), but rather a property editor. Unlike a widget, a property editor analyzes metadata associated with a given property, renders the appropriate widgets to edit that property and wires up data binding. Data is synchronized, validation is passed from the model to the UI, content assistance is made available, etc. This fundamentally changes the way developers interact with a UI framework. Instead of writing UI by telling the system how to do something, the developer tells the system what they intend to accomplish. When using Sapphire, the developer says "I want to edit LastName property of the person object". When using widget toolkits like SWT, the developer says "create label, create text box, lay them out like so, configure their settings, setup data binding and so on". By the time the developer is done, it is hard to see the original goal in the code that's produced. This results in UI that is inconsistent, brittle and difficult to maintain.
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

6. Validation, Data Binding, and Type Conversion - Spring Framework - 0 views

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    "There are pros and cons for considering validation as business logic, and Spring offers a design for validation (and data binding) that does not exclude either one of them. Specifically validation should not be tied to the web tier, should be easy to localize and it should be possible to plug in any validator available. Considering the above, Spring has come up with a Validator interface that is both basic ands eminently usable in every layer of an application. Data binding is useful for allowing user input to be dynamically bound to the domain model of an application (or whatever objects you use to process user input). Spring provides the so-called DataBinder to do exactly that. The Validator and the DataBinder make up the validation package, which is primarily used in but not limited to the MVC framework. The BeanWrapper is a fundamental concept in the Spring Framework and is used in a lot of places. However, you probably will not have the need to use the BeanWrapper directly. Because this is reference documentation however, we felt that some explanation might be in order. We will explain the BeanWrapper in this chapter since, if you were going to use it at all, you would most likely do so when trying to bind data to objects. Spring's DataBinder and the lower-level BeanWrapper both use PropertyEditors to parse and format property values. The PropertyEditor concept is part of the JavaBeans specification, and is also explained in this chapter. Spring 3 introduces a "core.convert" package that provides a general type conversion facility, as well as a higher-level "format" package for formatting UI field values. These new packages may be used as simpler alternatives to PropertyEditors, and will also be discussed in this chapter."
enderson james

Data Integration Solutions - 0 views

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    Aegis Software offering data integration solutions for your enterprise. We collect your enterprise data from different source and integrate them in your enterprise system or platforms through which you can increase your business performance and capabilities.
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.
anonymous

Large scale application development and MVP - Part II - Google Web Toolkit - Google Code - 0 views

  • itself
    • anonymous
       
      The View Implementation
  • @UiHandler("
  • presenter.onAddButtonClicked();
  • ...91 more annotations...
  • onAddButtonClicked
  • eventBus.fireEvent(new AddContactEvent());
  • presenter needs to know more about the view
  • view needs to know more about the data model
  • data types are typically homogeneous within column borders
  • ColumnDefinition abstract class
  • houses the any type-specific code (this is the third party mentioned above)
  • ColumnDefinition
  • ColumnDefinition(s) would be created outside of the presenter
  • we can reuse its logic regardless of what view we've attached ourself to
  • update our views such that we can set their ColumnDefinition(s).
  • setColumnDefinitions
  • this.columnDefinitions = columnDefinitions;
  • so that we can pass in
  • a mocked ContactsView instance when testing our ContactsPresenter
  • in our AppController, when we create the ContactsView,
  • new ContactsViewColumnDefinitions().getColumnDefinitions();
  • we can initialize it with the necessary ColumnDefinition(s).
  • contactsView.setColumnDefiniions(
    • anonymous
       
      Initialize ContactsView with the necessary ColumnDefinition(s)
  • With our ColumnDefinition(s) we can pass the model untouched.
  • As mentioned above we were previously dumbing down the model into a list of Strings
  • current solution
  • List<String> data
  • display.setData(data);
  • how that data type is rendered.
  • use generics
  • third party that abstracts
  • knowledge of a cell's data type
  • stringing together a list of these classes
  • providing the necessary render()
  • and isClickable()/isSelectable() override
  • ContactsViewColumnDefinitions<ContactDetails>
  • columnDefinitions =      new ArrayList<ColumnDefinition<ContactDetails>>()
  • ColumnDefinition<T>
  • ContactsPresenter
  • ContactsViewImpl
  • ColumnDefinition<T> columnDefinition = columnDefinitions.get(j);
  • the presenter can pass the model untouched
  • the view has no rendering code
  • that we would otherwise need to test. And the fun doesn't stop there.
  • presenter.onItemClicked(
  • presenter.onItemSelected
  • ClickEvent
  • cell.getCellIndex()
  • columnDefinition.isClickable()
  • SelectEvent
  • columnDefinition.isSelectable()
  • return shouldFireClickEvent;
  • return shouldFireSelectEvent;
  • respond to user interaction in different ways based upon the cell type that was clicked
  • use them for rendering purposes
  • defining how to interpret user interactions
  • we're going to remove any application state from the ContactsView
  • replace the view's getSelectedRows() with a SelectionModel
  • The SelectionModel is nothing more than a wrapper around a list of model objects.
  • ContactsPresenter holds on to an instance of this class
  • onItemSelected
  • Having the ColumnDefinition create a new widget for each cell is too heavy
  • Replace our FlexTable implementation with an HTML widget
  • calling setHTML()
  • Reduce the event overhead by sinking events on the HTML widget
  • rather than the individual cells
  • update our ContactsView.ui.xml file to use a
  • HTML widget rather than a FlexTable widget.
  • <g:HTML ui:field="contactsTable">
  • Inefficiencies related to inserting new elements via DOM manipulation Overhead associated with sinking events per Widget
  • for each item ask our column definitions to render accordingly
  • each column definition
  • render itself into the StringBuilder
  • rather than passing back a full-on widget
  • calling setHTML on a HTML widget
  • rather than calling setWidget on a FlexTable.
  • This will decrease your load time, especially as your tables start to grow.
  • we're reducing the overhead of sinking events on per-cell widgets
  • instead sinking on a single container
  • ClickEvents are still wired up via our UiHandler annotations
  • get the Element that was clicked on
  • and walk the DOM until we find a parent TableCellElement
  • we can determine the row
  • shouldFirdClickEvent() and shouldFireSelectEvent()
  • to take as a parameter a TableCellElement rather than a HTMLTable.Cell.
  • faster startup times via Code Splitting.
  • runAsync() points
  • split portion of your code is purely segmented
  • not referenced by other parts of the app
  • it will be downloaded and executed at the point that it needs to run
  • Do we really want to download all of that code before the user even logs in?
  • Not really.
  • simply grab the login code, and leave the rest for when we actually need it
  • wrap the code that creates the ContactsView and ContactsPresenter in a runAsync() call
  • as optimizations such as this one become easier and easier to implement.
Hendy Irawan

AtomServer 2.3.4 - - 0 views

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    "AtomServer is a generic data store implemented as a RESTful web service. It is designed as a GData-style Atom Store. It is based on the following concepts and protocols; REST. REST is a design pattern. It's not a technology like SOAP or HTTP. REST is a proven design pattern for building loosely-coupled, highly-scalable applications. There are important benefits to sticking to the REST design pattern; Simple. REST is incredibly simple to define. There are just a handful of principles and well defined semantics associated with it. Scalable. REST leads to a very scalable solution by promoting a stateless protocol and allowing state to be distributed across the web. Layered. REST allows any number of intermediaries, such as proxies, gateways, and firewalls. Ultimately REST is just a web site, albeit one that adheres to a design pattern, so one can easily layer aspects such as Security, Compression, etc. on an as needed basis. Atom. Fundamentally, Atom is an XML vocabulary for describing lists of timestamped entries. These entries can be anything, although because Atom was originally conceived to replace RSS, Atom lists are Feeds, and the items in the lists are Entries. Atom is a RESTful protocol. AtomServer stands on the shoulders of giants. It is built on top of several open source projects - most notably, Apache Abdera (a Java-based Atom Publishing framework) and Spring. AtomServer is an Atom Store. Thus, it requires a relational database to run. AtomServer currently supports; PostgresSQL, SQLServer, and HSQLDB. Using HSQLDB, AtomServer requires zero configuration and can run out-of-the-box. While this configuration is suitable for many applications, those that see significant load will likely require a database with better transactional semantics, such as PostgreSQL. AtomServer is easy to use. It deploys as a simple WAR file into any Servlet container. Or alternately, can be used out-of-the-box as a standalone server, running with
Javin Paul

Where to Use Assertion in Java with Example - 0 views

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    Quick guide on where to use Assertion in Java with code example. Assertion in java is fairly underused feature but if used carefully can complement both Unit Testing and Exception handling. Since Assertion sits on code its gets more expose than unit testing and can test your function with more real data than one or two test data.
Hendy Irawan

JBoss Transactions - JBoss Community - 0 views

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    "In todays business environment data corruption can have serious consequences for the enterprise including service unavailability, system reconciliation costs, and damage to customer relationships and business reputation. The JBoss Transaction Service (JBossTS) protects businesses from data corruption by guaranteeing complete, accurate business transactions for Java based applications (including those written for the JEE and EJB frameworks) thereby eliminating the risks and costs associated with time-consuming manual reconciliation following failures."
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
Dan Martin

Chronon | Time Traveling Debugger and Recorder for Java - 0 views

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    A "flight data recorder" and correstponding "time traveling debugger" to playback the data. Integrated into Eclipse.
DJHell .

Hades - Übersicht - redmine.synyx.org - 0 views

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    Hades is a utility library to work with Data Access Objects implemented with Spring and JPA. The main goal is to ease the development and operation of a data access layer in application
abuwipp

ResultSet (Java 2 Platform SE 5.0) - 0 views

  • to insert column values into the insert row. An updatable ResultSet object has a special row associated with it that serves as a staging area for building a row to be inserted. The following code fragment moves the cursor to the insert row, builds a three-column row, and inserts it into rs and into the data source table using the method insertRow
  • moveToInsertRow
  • updateString
  • ...1 more annotation...
  • insertRow
  •  
    to insert column values into the insert row. An updatable ResultSet object has a special row associated with it that serves as a staging area for building a row to be inserted. The following code fragment moves the cursor to the insert row, builds a three-column row, and inserts it into rs and into the data source table using the method insertRow.
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. "
mahesh 1234

Encapsulation, Encapsulation in Java, Encapsulation Tutorial, Encapsulation Example- Ja... - 0 views

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    Encapsulation is a process of wrapping code and data together into a single unit. It is a way to achieve data hiding.
mahesh 1234

Array in Java - 0 views

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    Normally, array is a collection of similar type of elements that have contigious memory location. In java, array is an object the contains elements of similar data type. It is a data structure where we store similar elements. We can store only fixed elements in an array.
mahesh 1234

JSP Tutorial, JavaServer Pages Technology (JSP) - javatpoint - 0 views

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    JSP Tutorial - Javatpoint website provides you a complete JSP tutorial with practical programming examples and easy steps using this beginner's tutorial containing basic to advanced knowledge of Java JSP Technology including Form Data, HTTP Request Header, Response Header, Scripting elements, Directive elements, Custom tags, Cookies Handling and Session Tracking.
mahesh 1234

Variable and Data Type in Java - Javatpoint - 0 views

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    Variable and Datatype in Java. Variable is a reserved area allocated in memory.There are three types of variable local,instance and static.There are 8 primitive data types.
henry klingberg

Redirect After Post - 0 views

  • input data, which can change state of server application
  • reloading result page using Refresh/Reload
  • Instead of returning a result page immediately in response to POST request, server responds with redirect to result page. Browser loads the result page as if it were an separate resource
  • ...2 more annotations...
  • When a user tries to refresh the result page, browser resends an "empty" GET request to the server. This request does not contain any input data and does not change server status
  • The vehicle which makes transition from POST to GET possible is redirection.
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