Automatically remove unused parameters from constructor (Eclipse, Java)

Question

I have a bunch of classes which contain constructors with unused parameters. For example this one:

class Book {

    String author;
    String title;

    public Book(String author, String title, int numberOfPages) {       
        this.author = author;
        this.title = title;
    }
}

Does Eclipse offer any way of automatically removing these unused parameters over multiple files? Removing them manually would take hours.

Answer 1

On Eclipse Juno, you can set the compiler to show a warning/error when there's an unused parameter.

1. Open Window -> Preferences
2. Navigate to Java -> Compiler -> Errors/Warnings
3. Find the node called Unnecessary code
4. Set the Value of parameter is not used to Warning or (better) Error .

This way the compiler will show a warning or will even fail to compile if there are unused method/constructor parameters.

In this case, when you navigate to the Problems view, you can apply a Quick Fix with a mouse right-click.

Answer 2

Go to Windows->Preference->Java->Compiler->Errors/Warnings

In that Unnecessary Code tab. Make Value of Parameter is not used as Error from Ignore or Warning .