Why do software engineers and software developers prefer Eclipse, and not Java?

Java is a programming language and eclipse is the IDE to write java . Most developers use it because it has a lot of plugins and mods that support several project types.

Eclipse is a platform where Java is a programming language. Eclipse is used as a tool where all the programming languages can be run and compiled.

Because it is a "free" consoledated tool (IDE) which enable JAVA programmers to have an integrated environment with many other system i.e. Adobe Flex user interface, Hibernate (Database interface), ...etc.

It is so easy to install the ADD-IN file and start using both software under one programming tool.

I think You are in wrong Perception toward java and eclipse, ,  Java is an Programming Language to build Applications and to make ease building/Developing Java Applications , eclipses is used as a tool which is basically a platform.

Without using eclipse also, we can develop java applications.

i think it's not a fair compression because there  a huge differences between tow of them from  my perspective   i see that software engineers are preferred an IDE the offer them an integrated tools for testing and analysis  depends on the tools that are  used by Software developer and the developers try to use the right Programming language  which is Compatible,Reliable and meet the project requirements

Java is the language that is written using Eclipse. Eclipse being a tool it only helps along writing Java code so no such comparision can be made. 

Your topic could have been Why software Engineers and Software developers prefer Eclipse and not notepad?

Eclipse is the Platform or IDE to build applications with help of the programming language JAVA . Java is platform independent and  can even run without eclipse platform. Eclipse is a much easier tool for developing android applications with help of Java codes

Java is the language that is written using Eclipse. Eclipse being a tool it only helps along writing Java code so no such comparision can be made. 

Your topic could have been Why software Engineers and Software developers prefer Eclipse and not notepad?

Eclipse is the Platform or IDE to build applications with help of the programming language JAVA . Java is platform independent and  can even run without eclipse platform. Eclipse is a much easier tool for developing android applications with help of Java codes

Perhaps Eclipse more towards physics and mathematics, while Java is more to programming language. Thus, Eclipse matches Reservoir Engineer as an applicable tools for their engineering evaluation and physic-math basis.

well i think you have misunderstanding here

java is a programming language, from the other hand eclipse is platform use java language  

so basically  when you use eclipse  you will be writing a program using java  language