IntelliJ 8 provides 7 new refactorings. One new powerful refactoring is the Introduce Parameter Object. The name speaks for itself: it introduces a parameter object! But what does it really do? The refactoring promotes good encapsulation. It encapsulates fields by introducing a new object for them.
For example, you might encounter or write the following piece of code:
public class Parser { public void parse(String firstName, String lastName) { // firstName and lastName handling here } public void testParser() { new Parser().parse("erik", "pragt"); } }
The method call consists of two Strings, but a better approach might be to encapsulate those fields into a new class, for example ‘Name’. This refactoring does exactly that. Just select the ‘parse’ method, go to Refactor -> Introduce Parameter Object, which will look like:
public class Name { private final String firstName; private final String lastName; public Name(String firstName, String lastName) { this.firstName = firstName; this.lastName = lastName; } public String getFirstName() { return firstName; } public String getLastName() { return lastName; } } public class Parser { public void parse(Name name) { // name handling here } public void testParser() { new Parser().parse(new Name("erik", "pragt")); } }
After refactoring, you’re code will look like this, which is a much better typed version of the previous one!
Eclipse has it 🙂
Select the parameters, Alt+Shft+T –> Introduce Parameter Object
Oh!!! Just wait for the next blog!!
I bet IntelliJ had that feature first 😛 lol
Well, ehhmm,…this is a *new* refactoring… But I guess it’s good that IntelliJ finally borrows something back! 😉
And then you have to introduce another “Parameter Object” to the Name class that will take two parameters:
@Constructor
public Person(PersonParameters parameters) {
this.firstName = parameters.getFirstName();
this.lastName = parameters.getLastName();
}
with resulting code:
parser = new Parser(new Name(parameters));
etc…
is @Re-curse a reserved annotation or a keyword to be filtered?
I love it.
Which version are you using? I am using 8.0M1 and I don’t seem to be able to find it.
Thanks
Never mind. I have just learned that the final 8.0 release is out.