How to extract a method across files?

Question

In all my java files of my project, I want to replace occurrences of this:

myObject.getName() == null

With that:

myObject.hasName()

Is there any action or strategy to do this with IntelliJ IDEA?

• I want it to be specific to the getName method of my class MyClass and not to replace code, that refers to methods called getName of other classes.
• I want it to find as many matches as possible. It should not care about additional spaces, linebreaks, etc. If the variable has another name (like myObj or objX) it should also work. Calls like getObject().getName() should also be found. (The search has to care about semantics).
• I want it to be fast and not to require me to go through the hundreds of matches one by one.

Answer 1

Use Find and Replace Code Duplicates.

1. Create the instance method:

   public boolean hasName() {
       return getName() == null;
   }
   

   • To do that, I would suggest selecting myObject.getName() == null, then using actions Refactor | Extract | Method... and Refactor | Move..., so you don't have to type any code.

2. Click on the method and use Refactor | Find and Replace Code Duplicates.

   • However it will not refactor usages like these:

     String name = myObject.getName();
     if (name == null) {
         ...
     }
     

   • You can also use this action on a non-instance method:

     private boolean hasName(MyClass myObject) {
         return myObject.getName() == null;
     }
     

     which will result in making the method static, then use Refactor | Convert To Instance Method. Same result.

Answer 2

Use Structural Search & Replace (Edit | Find | Replace Structurally...), it is designed for use cases like this.

Use Search template:

$x$.getName() == null

Replacement template:

$x$.hasName()

Click the Edit Variables... button and specify Expression type (regexp) as MyClass. When searching this will also find your example of getObject().getName() == null