Syntax Semantics UML Java Jan Pettersen Nytun page

Syntax & Semantics UML - Java Jan Pettersen Nytun, page no. 1

Syntax From Wikipedia, the free encyclopedia: “…the syntax of a computer language is the set of rules that defines the combinations of symbols that are considered to be a correctly structured document or fragment in that language. ” Java has textual syntax. The If-sentence bellow is syntactically correct: First code word if followed by token ( , etc. … int age = 10; if (age >70){ System. out. println(“Can be retired!"); } else { System. out. println("Can not be retired!"); } Jan Pettersen Nytun, UIA, page 2

UML Has a Vusuall Syntax (and also a textual one) If sentence in an activity diagram: age = 10 [age>70] [else] Print: «Can be retired!» Print: «Can not be retired!» Jan Pettersen Nytun, UIA, page 3

Semantics The study of meanings. Used to differentiate the meaning of an instruction from its format. int age = 10; if (age >70){ System. out. println(“Can be retired!"); } else { System. out. println("Can not be retired!"); } Semantics of the if-sentence: If the boolean expression evaluates to true then execute what is between { and }. . . [age>70] age= 10 [else] Print: «Can be retired!» Here the symbol function as a merge (i. e. , not an if) Print: «Can not be retired!» The samantics of a branch is the «same as» the if sentence. Jan Pettersen Nytun, UIA, page 4

Code Generation Semantics of UML constructions expressed with Java expressions package Journal. model; public class Person { private String first. Name; private String last. Name; } package Journal. model; public class Patient extends Person{ private Patient. File has; } package Journal. model; public class Patient. File{ private java. util. List<Patient. Record> contains; private Patient concerns; } Jan Pettersen Nytun, UIA, page 5

Magic. Draw: UML Java public class Patient. File{ private java. util. List<Patient. Record> contains; . . . Introduction to Object-oriented Software Development, J. Pettersen Nytun page no. 6, 3/3/2021

Operations Method public class Person { private String first. Name; private String last. Name; public String get. Name( ){ return null; } public void set. Name( String name ){ } } Jan Pettersen Nytun, UIA, page 7

This was problematic in Magic. Draw. Did some reverse engineering to get this in place. . . package Journal. controller; import Journal. model. Patient. File; public class Journal. App { private java. util. List<Patient. File> patient. Files; public static void main( String[] args ){ } } Jan Pettersen Nytun, UIA, page 8

Magic. Draw - I Meny velg: Tools/Generate Code/Java Jan Pettersen Nytun, UIA, page 9

Software Engineering Ref. : http: //developeriq. in/articles/2013/dec/24/the-myth-of-software-reengineering/ Jan Pettersen Nytun, UIA, page 10