IntelliJ IDEA 2018.2 Help

Type Migration

The Type Migration refactoring lets you automatically change a member type (e.g. from integer to string), and data flow dependent type entries, like method return types, local variables, parameters etc. across the entire project.

It also lets you automatically convert variable or method return type between arrays and collections. If any conflicts are found IntelliJ IDEA displays the appropriate message.

  1. In the editor, highlight or place the caret at a type you want to refactor.
  2. Press Ctrl+Shift+F6 or on the main menu, select Refactor | Type Migration.
  3. In the dialog that opens, specify the new type and scope where to look for the usages.
  4. Preview and apply the changes.

Examples

f: int -> String

BeforeAfter
int f; void bar(int i) {} void foo() { bar(f); }
String f; void bar(String i) {} void foo() { bar(f); }

I<String> -> I<Integer>

BeforeAfter
interface I<T> { T foo(T t); } class A implements I<String> { String myString; public String foo(final String s) { if (s == null) { return myString; } return s; } }
interface I<T> { T foo(T t); } class A implements I<Integer> { Integer myString; public Integer foo(final Integer s) { if (s == null) { return myString; } return s; } }

myResult: ArrayList<String> -> String[]

BeforeAfter
public class ResultContainer { private ArrayList<String> myResult; public String[] getResult() { return myResult.toArray(new String[myResult.size()]); } }
public class ResultContainer { private String[] myResult; public String[] getResult() { return myResult; } }
Last modified: 14 June 2018

See Also