What does JAVA really do? Why is the technology actually used very little? __java

The question comes from a netizen's question
I am now engaged in the development of Java,
My Foundation: Java Foundation (not strong, very superficial), JS script sometimes used, struts1. X, simple Oracle operation, simple Linux/unix use,.

My question:
1.java can be engaged in which aspects of the open, from the application areas, such as Web sites, search technology, ERP systems and so on ...
2, engaged in Java, after the feeling of not using too much of the real java-based technology, what multithreading, very little ... The feeling is the frame ...

Because of the superficial understanding of Java technology, as well as work experience only a year, under the banner of technology, mixed for a year, due to limited technology, do not develop projects experience,
General Handyman, now like technology, want to have a vision of the industry,
Hope Master pointing.


Reply 1:
Java can do a lot of work.
Site, now used very much, this is needless to say.
Workflow system, most of it is Java, some foreign strong scientific workflow is also java.
Data-intensive computing, Hadoop is a good implementation, and now there are more and more people.
Search, Lucence.


Reply 2:
True technology is the solution to the problem, not the skill, the skill is easy to master, but the ability to solve the problem is not so easy to improve.
Do not underestimate the jee of those frameworks, you can really understand is also to take some time and energy.
Our job as a programmer is to analyze the problem and then solve the problem.
For the status of the landlord, personal suggestions are:
1, learn a good Java Foundation.
2, learn several mainstream frameworks, such as spring, struts, hibernate, Ibatis and so on.
3, learn good database and SQL, for the mainstream database to have some preliminary understanding, including Oracle, SQL Server, DB2 and so on.
With the above 3 Foundation, you need to do some projects, accumulate experience, this is even getting started.

My personal point of viewJava Century web
1 know what the various parts of Java can do and do not need to know exactly how to do it.
2 when needed, a detailed study of the corresponding section
I think that way, you will not be too confused. which is similar to
I know that some precision instruments have 100 functions, but I currently use only 10 of them, so we know more about these 10, but we have to know there are 90.