Under what circumstances is node.js suitable?

  node.js, question

1. As a java programmer, especially in China, this kind of software is multi-habitat, if not full stack. I’ve heard too much about node.js before, but I didn’t bother to study it.
2. Recently, I began to study node.js slowly, because it is a small white, but also because I am a back-end development. Looking at it, I am somewhat confused. In the actual business scenario, what kind of situation is more reasonable to adopt node.js.
3. I hope experienced great gods can give me some classic cases (I know node.js can do a lot of things, but why should I give up the familiar java language and choose it, which may be extreme, but I like to have a strong persuasion point on technology selection)

Park Ling said in “Node.js” that:
Node’s application scenarios are

  1. I/O intensive

  2. Central Processor intensive business

  3. There are legacy systems

  4. Distributed application

Getting Started Case:A simple Node.js microblog

Also, why give up Java?