Well. You're right that almost all java code is written this way. The reason it's an anti pattern is that one of the main principles of object oriented design is to combine data and the functions that operate on it into a single object. For example when I was writing old school c code, we would mimic object oriented design like this:
struct SomeStruct {
int x;
float y;
};
void some_op_i(SomeStruct* s, int x) {
// do something
}
void some_op_f(SomeStruct* s, float y) {
// something else
}
Which is to say that the language didn't allow us to combine the functions to operate on SomeStruct inside of the struct, so we created a group of free functions that by convention took SomeStruct as a first param.
When c++ came along, the struct became a class, and it allows you to put functions into the struct (class). Then the struct is implicitly passed as the this pointer, so instead of creating a struct and passing it to functions, you create the class and call methods against it. The code is more clear and easier to understand this way.
Then I moved to the java world, and everyone separates the model from the service, which is to say the model is a glorified struct, and the service, being stateless as it is, becomes a collection of functions that operates on a model. Which to me, sounds suspiciously like a c language idiom. It's pretty funny because in c it was done because the language didn't offer anything better, and in java it's done because the programmers don't know any better.
