Re: field access or property access or both?

[Patrick Linskey]

Hi,




-Patrick

On Jun 17, 2008, at 3:50 PM, Andrei Tchijov wrote:

Note that with OpenJPA, if you were to explicitly enhance the other classes that access the visible persistent fields directly, things would work.

Thanks Mike. It makes perfect sense. I assume this is due to the fact that "@Entity" class gets "enhanced", not all other classes which happen to use it.

On Jun 17, 2008, at 17:16 , Michael Dick wrote:

Hi Andrei,


accessor methods.

From section 2.1 and 2.1.1 of the JPA specification
2.1
. . .

which may correspond to Java-

within the methods of the
entity by the entity instance itself.* Instance variables must not be
accessed by clients of the entity. The
state of the entity is available to clients only through the entity's
accessor methods (getter/setter methods)

or package visibility.

2.1.1 Persistent Fields and Properties

runtime[1] either via JavaBeans

(field or property access) applies

mapping annotations on either

the access type as being either
field- or property-based access respectively.
. . .
[1] The term "persistence provider runtime" refers to the runtime

implementation integrated with it.
. . .


variable.

Hope this helps,

-mike



wrote:

You're not alone, I had the same misconception. Field and property access apply to how the persistence provider runtime accesses the state of an entity. Regardless of the access type the client should use the entity's The persistent state of an entity is represented by instance variables, Beans properties. An instance variable may be directly accessed only from or other business methods*. Instance variables must be private, protected, The persistent state of an entity is accessed by the persistence provider style property accessors or via instance variables. A single access type to an entity hierarchy. When annotations are used, the placement of the the persistent fields or persistent properties of the entity class specifies environment of the persistence implementation. In Java EE environments, this may be the Java EE container or a third-party persistence provider So technically the second option is the more correct way to set a state On Tue, Jun 17, 2008 at 2:27 PM, Andrei Tchijov <[EMAIL PROTECTED] >

I guess I m doing something wrong. Please enlighten me what it is I am

doing wrong.

I have a class with number of fields.  One of which is boolean.

@Entity
class A {
...
@Basic
boolean         foo;
...
}


do "opposite".  Somewhere else in my code I have


...
     _tx.begin();
             A a = getA();
             a.foo = !a.foo;
     _tx.commit();
...


really puzzled is that if I change code like this:


@Entity
class A {
...
@Basic
boolean                foo;
...
public void setFoo( boolean v ) {
this.foo = v;
}
}


...
     _tx.begin();
             A a = getA();
             a.setFoo( ! a.foo );
     _tx.commit();
...


To complete picture, I should mention that I am running "outside of
container" (stand alone application).

Any help will be highly appreciated.

Andrei

OpenJPA doing wonderful job of retrieving "state" of the objects of this class (including 'foo' field). What puzzles me is that it seems to fail to It looks similar enough to examples from documentation, but it does not work. I am quite confident that "a" is in "attached" state when I am trying to change "condition" field (_em.contans(a ) returns true ). What makes me

--
Patrick Linskey
202 669 5907

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