I will try to give you my sense of these answers.
There are no exact answers because programming  and
computing in genereal is an unregulated area of employment,
as opposed to a licensed engineer or architect, for
example.1. The training is determined by the employer. Some
are willing to take minimal training if they know the
individual. Others require 2year and 4year degrees. Others
only need formal training at a technical institute.
Many accept on-the job training. Expect to receive
more money for more training.2. Some employers
only consider degreed applicants. Others don't care
about degrees. You can get into the field  without
college level  courses. Some jobs require a certification
for the specific area. Many employers would like to
see a Java certificate and some insist on it. A
programming certificate is relatively easy to obtain (it is a
hard test but you only have to study at your own pace,
if you choose). Some employers will accept that as
an indicator of your ability. Experience adds to
that, as well.2. You must be able to take a
description of a problem and translate that into Java source
code in a manner that is legible and obeys the general
rules for Object-Oriented design. You should understnd
these rules and apply them on the job. You must be able
to operate in the environment where you are
programming, test and document your programs. Communication of
your status is generally expected.4. The
positive aspect is that you generally are free to problem
solve and to use your logic skills. You will be paid
nominally or above, when compared to the general work
force. You get to work  with computers and tell them what
to do, instead of the reverse situation.5.
This is not a rosy occupation. You deal with a lot of
sharp individuals who have strong egoes and elevated
views of their own importance. You are required  to sit
for endless hours before potentially hazardous
radiation sources and spew out countless lines of dull,
boring code, maniputlating dull, boring data. You
genererally work in a cubicle or other space devoid of
privacy and are open to constant interruption.6.
Salary ranges are dependent upon education, training and
experience, generally. They are dependent upon geography, as
well, as this affects the cost of living. In US$ you
can expect to earn anywhere from 10,000$/year up
through 200,000/year. The averages are probably in the
$40-90k/year range for a Java programmer. These are all
guesses, by the way!This is a very competitive
field because it does pay well and it is easy to enter.
Expect to be beat up continuously while getting into it.
But if you have the aptitude to stick with the
hardships, the monetary rewards are possible.