Netzwerg — Above, Below, and Beyond Tech Talk

Wednesday, January 04, 2006 3:46 PM | rahel luethy | 4 comment(s)

inline refactoring trick

consider the following scenario: you have a class Foo which offers a non-static method getFoo():

public class Foo {
 
 public String getFoo() {
  return "foo";
 }

}

you're wearing the refactoring hat and have decided to change the method to be static. of course you could just add a static modifier and fix all compile errors, but let's assume that your method is used a gazillion times in your project, so this is not really an option...

tada! here comes the inline refactoring trick (I haven't invented it, but somehow I can't find the original article anymore):

perform a rename method refactoring and change getFoo() to getBar():

public class Foo {
 
 public String getBar() {
  return "foo";
 }

}

duplicate the method, rename one of the duplicates back to getFoo(), and add the static modifier to the one still called getBar():

public class Foo {
 
 public String getFoo() {
  return "foo";
 }

 public static String getBar() {
  return "foo";
 }

}

replace the complete contents of getFoo() with a static call to getBar():

public class Foo {
 
 public String getFoo() {
  return Foo.getBar();
 }
 
 public static String getBar() {
  return "foo";
 }

}

here comes the magic: perform an inline refactoring on the getFoo() method, which will change all former callers of getFoo() to now invoke Foo.getBar()
rename getBar() back to getFoo()
take off that STUPID HAT

note that the same magic works for more complicated scenarios, like refactoring a class with static methods into a singleton.