Group items tagged

highly type-safe

consistent

portable

CDI enhances the Java EE programming model in two more important ways

allows you to use EJBs directly as JSF backing beans

CDI allows you to manage the scope, state, life-cycle and context for objects in a much more declarative fashion, rather than the programmatic way

CDI has no component model of its own

set of services that are consumed by Java EE components such as managed beans, Servlets and EJBs.

well-defined create/destroy life-cycle that you can get callbacks for via the @PostConstruct and @PreDestroy annotations.

Managed beans

annotation

CDI also integrates with JSF via EL bean name resolution

CDI does not directly support business component services such as transactions, security, remoting, messaging

JSR 330 defines a minimalistic API for dependency injection solutions and is primarily geared towards non-Java EE environments.

Figure 1 shows how CDI fits with the major APIs in the Java EE platform.

none of this uses string names that can be mistyped and all the code is in Java and so is checked at compile time

are additional pieces of meta-data that narrow down a particular class when more than one candidate for injection exists

If the JPA entities still do not look right, try to apply some JPA tricks like mapping a JPA-entity to several tables, or even map JPA-entities to DB-views, to improve the situation

Rename the classes into some more meaningful. The attribute, class names are in general everything but not fluent

Junit. Purpose: JPA mapping verification

Thinking In Structs Not Objects

12 Tips On JPA Domain Modelling

Execute the "Unit" tests after every change

even better get rid of them

domain objects are

What is next after robustness diagrams? Robustness diagrams often act as bridge from use cases to other models.  For example, it is quite common to create sequence diagrams which represent the detailed design logic required to support the use case

Add an entity for each business concept

Add a use case whenever one is included in the scenario

Add a controller for activities that involve several other elements

Add a controller for each business rule

Add a controller to manage the overall process of the scenario being modeled

Add a boundary element for each major user interface element such as a screen or a report.

for each workspace, in files stored in <workspace>/.metadata/.plugin/org.eclipse.core.runtime/.settings

for each project --for project-level settings -- in files stored in a .settings sub-directory of your project folder

Is there an UML editor for Eclipse? An Eclipse Modelling project-based UML editor can be installed from the Eclipse update site "Modelling > UML2 Tools SDK". See Creating UML 2 diagrams with Eclipse UML2 Tools - Tutorial for an introduction.

How do I debug Eclipse? How can I see what plug-ins are being started? Why aren't the plug-ins I installed showing up in the UI? How do I start the OSGi console?

Debugging OSGi Bundle Loading Issues There are a few flags you can pass to Eclipse on the commandline or in your eclipse.ini file that might help: -consolelog - log everything in workspace/.metadata/.log to the console where you launched Eclipse as well -debug - more verbose console output -console - start the Equinox OSGi console to interact with OSGi directly -noexit - when Eclipse closes, keep the OSGi console running until you type 'exit' or hit CTRL-C so you can keep debugging See Where Is My Bundle? for an overview of how to use the OSGi console for diagnosing problems.

Debugging Eclipse Using Eclipse You can also debug an Eclipse instance from another instance through remote debugging: Start the instance to be debugged with "-vmargs -Xdebug -agentlib:jdwp=transport=dt_socket,server=y,address=8000". You should see a message like "Listening for transport dt_socket at address: 8000" Open Run → Debug Configurations... and create a Remote Java Application configuration with connection type "Socket Attach" and connecting to the client at port 8000. Set the project to a bundle project with the right dependencies for the bundles that you are trying to debug. Launch the configuration. The JDWP agent supports other useful arguments, like "suspend=n" so that the process does not suspend. For more details, see Oracle's Java Debug Wire Protocol (JDWP) connection docs.

I just installed Eclipse on my 64-bit system, but it does not start. What is the problem? Make sure that you have downloaded the 64-bit version of Eclipse (it should have x86_64 somewhere in its name) and have installed a 64-bit JVM. Likewise, if you run a 32-bit JVM, then you should use the 32-bit version of Eclipse.

When I start Eclipse it says "Workspace in use or cannot be created, choose a different one.", what should I do? There are a couple of things you can try. Delete the workspace/.metadata/.lock file. Check your running processes to make sure there aren't any remaining Java or Eclipse processes running. When in doubt, restart your computer. :) Try starting Eclipse on a different workspace (from the workspace selection dialog, or by using a command line argument like -data /home/user/tmp-workspace), then switch back to your original workspace.

How do I uninstall a plug-in? You can view your list of installed software by checking your installation details from about dialog. Help > About > Installation Details

I'm having memory, heap, or permgen problems, what can I do? FAQ How do I increase the heap size available to Eclipse? FAQ How do I increase the permgen size available to Eclipse?

Eclipse seems to be hanging on startup. How can I find out why? If none of the solutions outlined in this section reveal the problem, then you can try debugging an Eclipse instance as a debug target from another Eclipse instance. This is surprisingly easy: Start Eclipse in a "new" blank workspace (e.g., C:\TEMP\WS, or /tmp) Create a new Debug configuration: Run -> Debug Configurations; then click on "Eclipse Applications" and select the New Launch Configuration. If you believe it's something about a particular workspace, then set the workspace to your normal workspace. If you believe the hang is caused by a particular plugin, disable the plugin and verify. Launch and then see. Using this approach, you can break with the debugger to see where hangs are occurring. You can also change the selection of plugins that the instance is launched with.

I was working on a project and doing something or other does not work. Where should I start? Try refreshing your projects. Try cleaning your your projects using the menu item Project/Clean to trigger a rebuild. Try closing/reopening your projects. Try restarting Eclipse.

4.2 Where are Eclipse's log files located?

Where are Eclipse's log files located? <workspace>/.metadata/.log You can view this workspace log as a view if you have PDE installed on your computer (which you would if you have downloaded the Eclipse SDK). You can open that view via Window -> Show View -> Other -> PDE Runtime -> Error Log. <eclipse install>/configuration/<sometimestamp>.log <eclipse install>/configuration/org.eclipse.update/install.log

Where are Eclipse preferences stored?

Where are Eclipse preferences stored?

Where are Eclipse preferences stored?

Where are update site bookmarks stored? It is within an XML file called <user_home>/.eclipse/org.eclipse.platform_3.1.2/configuration/org.eclipse.update/bookmarks.xml. Your Eclipse version may vary.

for GraniteDS users keeping their Java domain model and ActionScript3 domain model in sync via Gas3, the constraints are kept in sync

a couple of gotchas to be aware of

the constraint implementation is in the same class as the constraint declaration (not a problem in a dynamic language) @Pattern has a sightly different semantic because the regexp engine in Flex is a bit different. instead of the features provided by ConstraintValidatorContext, you can define a properties attribute in your constraints to make it belong to several sub-properties. not as flexible but good enough in many cases.

information than the model you use to

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without a time zone to model the domain

but not when adding a Place

FIELD

PROPERTY

Either all annotations must be on the fields, or all annotations on the get methods, but not both (unless the @AccessType annotation is used)

if placed on a get method, then the class is using PROPERTY access

For FIELD access the class field value will be accessed directly to store and load the value from the database

field can be private or any other access type

For PROPERTY access the class get and set methods will be used to store and load the value from the database

PROPERTY has the advantage of allowing the application to perform conversion of the database value when storing it in the object

be careful to not put any side-affects in the get/set methods that could interfere with persistence

Common Problems

Odd behavior

One common issue that can cause odd behavior is

For this reason it is generally recommended to

causing duplicate inserts, missed updates, or a corrupt object model

if you are going to use property access, ensure your property methods are free of side effects