Java – what is a component

I listen to podcast Java pose. There are often discussions about components here (note that components are not (clear) objects) They regret that Java has no components, unlike Net Components obviously make it easier to develop applications, not just GUI applications

I can learn from the discussion that a component has some characteristics related to decoupling (replacing one component with another is just a pipe problem) It has nothing to do with the property. It is absolutely related to events and representatives

So the question is:

Anyone can explain to me what a component is Why Java beans are not components

Anyone can explain how they help develop

./ Anyone can explain why Java doesn't have them if they are so useful

Solution

Software engineering radio has an episode on this topic: http://se-radio.net/podcast/2008-02/episode-87-software-components

The general idea is that a software component can describe its own dependencies and services in the form of metadata I don't know why you might hear that Java has no components, because you can imagine an architecture in Java, in which components describe themselves through metadata I think this is just the Java platform definition itself, and there is no real component architecture

Update: in fact, don't imagine such an architecture, because as others pointed out, Java beans or servlets can certainly be considered component-based architecture