Wrap return value
The Wrap Return Value refactoring allows you to select a method, and either create a wrapper class for its return values, or use an existing, compatible wrapper class. All returns from the method selected will be appropriately wrapped, and all calls to the method will have their returns unwrapped.
Wrapping a method's returns are useful, if your design changes in such a way that you want a method to return more information than originally planned. After wrapping, the wrapper class can be extended, allowing more data to be returned from the method. Also, it is common to wrap primitive return values, thus allowing interface and implementation to be decoupled as needed.
Open the desired class in the editor and place the caret at the method whose returns you wish to wrap.
Select on the main menu, or on the context menu.
In the dialog that opens, specify the name and package for the new wrapper class, or select an existing compatible wrapper class.
Preview and apply changes.
Example
Before | After |
|---|---|
class Order {
String customer;
String getCustomer() {
return customer;
}
}
|
class Order {
String customer;
Wrapper getCustomer() {
return new Wrapper(customer);
}
}
public class Wrapper {
private final String value;
public Wrapper(String value) {
this.value = value;
}
public String getValue() {
return value;
}
}
|
Wrap Return Value dialog
Use this refactoring to create a wrapper class around the return values of a method, or use a compatible existing class as a wrapper.
Item | Description | |
|---|---|---|
Method to wrap returns from | This read-only field shows the name of the selected method. | |
Create new class | Click this radio-button to create a new wrapper class. If this option is selected, specify the class and destination package name in the fields below. | |
Class name | Type the name of the new wrapper class. | |
Package name | By default, the current package name is displayed. You can type a different package name in the text field, or click the ellipsis button and select the destination package from the tree view. If the desired package doesn't exist, click | |
Target destination directory | Use this field to select the target destination directory. By default, the current destination directory is displayed. You usually choose the target destination based on a current package. If this package exists in multiple roots, you can click arrow button and select Leave in same source root from the list. In this case, wrapper would be placed near the initial class. You can click the ellipsis button to open Choose Destination Directory window. You can choose Directory Structure tab to select another destination directory or choose Choose By Neighbor Class tab to place a wrapper near the neighbor class if, for example, you want to put the wrapper in util directory near your Pair or Triple classes and you do not remember the exact package, putting wrapper near the Pair class would save you time. | |
Use existing class | Click this radio-button to use an existing class of your choice as a wrapper. | |
Name | Specify the name of the desired wrapper class. Note that such class should contain a constructor with a parameter of the same type as the return value in question. You can type the fully-qualified class name in the text field, or click the ellipsis button and choose the desired class in the Select parameter class dialog box. Note that you can select the desired wrapper class both from the project and non-project classes. | |
Wrapper field | Select the field that will store the return value, from the list of fields, encountered in the specified wrapper class. | |
Inner class | Click this radio-button to create an inner class. You might want to do that if, for example, you have a private method. In this case you can leave everything in the same class. | |
Name | Specify the name of the inner class. |
to create a new one.>