refactoring : Java Glossary

1. I have a method which has some code that I would like to pull out into its own method.
2. I highlight the offending code.
3. I select Extract Method from a popup menu
4. The Refactoring Browser asks me to name the method and automatically creates it and inserts the highlighted code.
5. In the current method, the highlighted code is replace by an invocation to the newly created method.

Ideally, in a perfectly written computer program, with a perfectly designed computer language, with a perfect SCID/ IDE, it should be possible to change any line/element of the program in isolation without having to make any supporting changes elsewhere. The program should still function in a reasonable way. For example, you should be able to change the allowable bounds on a field variable in one line of code (which might result in it internally being promoted from int to long), without having to manually adjust any other code. The basic principle is you should have to tell a computer any one fact, or decision in only one place. For example, you should have to tell a program which colour scheme to use in precisely one and only one place, and by ‘one place’ I mean one line of code. Real life computer languages and IDEs put up huge roadblocks to getting anywhere close to perfection.

IntelliJ

• Extract Method: I highlight a block of code that might be many line or just an expression. It then turns it into a method, figures out what the parameters need to be, and what type it returns. It then replaces the code with a call to the new method. It then finds similar code snippets and, with permission, also converts them to calls the new method.
• Introduce constant: converts literals to named constants. You have to give it some help to decide which instances to convert.
• Change signature: add, remove, rename, reorder the parameters of a method and automatically modify all invocations to the new rules.
• Global rename: my most common refactoring. Some people would not consider it a refactoring, but I consider it the most important tidying activity partly because it drives the decision of what code belongs where. IntelliJ renames with knowledge of Java syntax, so you don’t accidentally rename unrelated local variables with the same name. Lets you review which comments to rename. Lets you also rename similarly named variables and method in the same pop.
• Pull up: move a method or field from subclass to its superclass and make necessary adjustments. It will let you control just how much of its attached baggage of fields and methods you move with it.
• Push down: move a method or field from a superclass to one of its subclasses.
• Generify: add generics to a class.

Books

	recommend book⇒Refactoring : Improving the Design of Existing Code
		hardcover	kindle
	ISBN13:	978-0-201-48567-7	B000OZ0N4Y
	publisher:	Addison-Wesley
	published:	1999-07-08
	by:	Martin Fowler, Kent Beck (Contributor), John Brant (Contributor), William Opdyke, Don Roberts.
abe books.co.uk abe books.ca amazon.co.uk amazon.ca abe books.de chapters.indigo.ca amazon.de abe books.com abe books.fr amazon.com amazon.fr barnes and noble.com abe books.it powells.com iberlibro.com sony e-books abe books anz

	recommend book⇒Code Complete : A Practical Handbook of Software Construction
		paperback
	ISBN13:	978-1-55615-484-3
	publisher:	Microsoft Press
	published:	1993-05-14
	by:	Steve McConnell
Gives lots of practical advice on optimising. He talks mostly about C with examples in Fortran, Pascal, Basic and Ada. He doesn’t talk about Java. It didn’t exist when the book was written.
abe books.co.uk abe books.ca amazon.co.uk amazon.ca abe books.de chapters.indigo.ca amazon.de abe books.com abe books.fr amazon.com amazon.fr barnes and noble.com abe books.it powells.com iberlibro.com sony e-books abe books anz

	recommend book⇒Refactoring Workbook
		paperback
	ISBN13:	978-0-321-10929-3
	publisher:	Addison-Wesley
	published:	2003-09-06
	by:	William C. Wake
has exercises and real world examples. An emminently practical book.
abe books.co.uk abe books.ca amazon.co.uk amazon.ca abe books.de chapters.indigo.ca amazon.de abe books.com abe books.fr amazon.com amazon.fr barnes and noble.com abe books.it powells.com iberlibro.com sony e-books abe books anz