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0
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1answer
28 views

DTO and JPA Version

I have DB tables representing Employees and Departments. The server side(JavaEE) contains JPA entities representing the same. The client is a standalone client and communicates with the server using ...
2
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2answers
62 views

What's the correct approach to DAO layer in presence of ORM framework

I'm using JPA/Hibernate but probably it doesn't limit question. Currently I'm writing my data access code in my web controller classes. Thanks to JPA, in most cases this code is very simple, ...
0
votes
1answer
49 views

Can I ditch the persistence.xml file on JBoss?

I have a Spring based app where another programmer is using JPA's persistence.xml file to define the setup of hibernate and to define the entities that are being persisted. The app is using Spring's ...
1
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3answers
194 views

Limiting complexity in JPA programs Java/Hibernate

I've been working on a new application for some months now. It's my first big JPA program, and is still in the early stages. However, the complexity of my JPA object tree is becoming a growing ...
3
votes
1answer
318 views

Is this database design good? What JPA Entities should I create for this design?

I am trying my hands on JPA. For this I am thinking of using the example of a student admission process as shown in the diagram below. Is this design good ? Any suggestions for improvement are ...
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0answers
175 views

Best approach to save relationship mapping of country,state,city in orm

I am building a project in play framework java with jpa and I want set country,state,city dropdown fields in a form to be dynamic(from database).So only admin can increase or decrease the value of ...
0
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1answer
246 views

Producing JSON objects from JPA entities in REST API

I have a REST service producing JSON and consuming JSON. A lot of this are simple CRUD operations. My initial idea was to simply use the DAOs directly in the controller: @ResponseBody() ...
20
votes
5answers
656 views

Is staying implementation agnostic really worth it?

I have a project that I'm working on currently using Tomcat, Spring 4, Spring Security, MySQL, and JPA w/ Hibernate. I picked JPA from the standpoint that it's suppose to make swapping out the ...
0
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1answer
322 views

Where to put JPA annotations? Field, or getter?

version in field: @Column(name = "SAMPLE_STRING") private String sampleString; public String getSampleString(){ return sampleString; } version in getter: private String sampleString; ...
17
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4answers
1k views

How can I use unit tests and TDD to test an app that relies mostly on database CRUD operations?

At work, one of my projects is mostly about taking data passed in from an external client and persisting it in a database. It's a Java enterprise app using JPA and most of our logic revolves around ...
1
vote
1answer
987 views

Is Java's ElementCollection Considered a Bad Practice?

From my understanding, an ElementCollection has no primary key, is embedded with the class, and cannot be queried. This sounds pretty hefty, but it allows me the comfort of writing an enum class which ...
3
votes
1answer
202 views

ORM: Design of the service layer

I'm currently writing a medium sized web-application and find myself asking this question many times. For example, let's say there are users, which have files (one-to-many). How should the UI access ...
0
votes
1answer
639 views

Creating a separate project for JPA entities

Where I work it is a common practice to create a separate for JPA entities and a project for the web application (the WAR). So basically you have (at least) two project for each application - appJPA ...
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2answers
9k views

Entity to DTO Usage

Been trying to come up with a flow for a basic tiered web application, and have been reading conflicting information online. What I'm trying to figure out is if there is an advantage to still using ...
3
votes
3answers
875 views

When Business Object fields should not exactly reflect database columns

Main advantage with Hibernate annotations is the fact that a simple POJO (also called a Business Object the most of time) can become persistent through Hibernate annotations (or actually JPA) . In ...
2
votes
4answers
408 views

Should OO design, or database design, drive the coding of my @Entity classes?

I have two classes that I want related to each other in an JEE application using JPA2. In an OO world, I would say that a Chatroom has an attribute List messages. In the relational world composition ...
6
votes
1answer
4k views

IntelliJ with Maven compilation

I have a project that needs Hibernate jars. I added them as dependencies in the pom.xml and Maven compiles my project well. However, in the IDE, all annotations and calls to Hibernate API are marked ...
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2answers
2k views

Designing complex query builders in java/jpa/hibernate

I need to build complex sql queries programatically, based on large filter conditions. For example, below are few sample/hypothitical filter conditions, based on which i need to fetch users Country: ...
2
votes
1answer
1k views

When using Java Persistence API (JPA), which layer owns the entities?

When working with annotations on entities in JPA, do these entities belong to the model layer or the persistence layer? Does there have to be some kind of clone of the entities (simple JavaBeans) in ...
2
votes
3answers
287 views

in doubt of using code generators

I am now entering the world of java ee 6. And I am supposed to used different technologies like jsf, jpa, different kinds of beans and all that stuff. I am learning using the netbeans IDE, which is, ...
1
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1answer
1k views

Has JPA replaced CMP?

No question too stupid right :) Came across this on wikipedia The Java Persistence API replaces the persistence solution of EJB 2.0 CMP (Container Managed Persistence). My understanding was ...
2
votes
2answers
351 views

When designing data models for JPA, what's the best way to make use of polymorphism?

I've been asked to support a Java EE application. The data model was poorly-designed and will not support several necessary use cases; so I'm developing a new data model using EclipseLink (the old one ...
0
votes
2answers
989 views

Is JSF and JPA worth learning? [closed]

I'm attending a company sponsored training event for JSF and JPA that crams 10 days of training into 5 days. I plan on getting all that I can out of the class, but there is no "final exam".