Verificare şi Validarea Sistemelor Soft Tem ă Laborator 1 ESC/Java2 Extended Static Checker for Java Dat ă primire laborator: Lab 1 Dat ă predare laborator: Lab 1 si Lab 2

Verificare şi Validarea Sistemelor Soft Software engineering problem: building/maintaining correct systems. How? Specification Tools Contract between caller (~user) and implementation (~provider). What the implementation can expect from the caller. What the caller can expect from the implementation. You don’t brake contract, that’s illegal!

Verificare şi Validarea Sistemelor Soft Precondition Specifies “caller’s responsibility” Constraints on parameter values and target object’s state. Valid object’s states, in which a method can be called. Intuitively Expression that must hold at the entry to the method. Method contract Postcondition Specifies “implementation’s responsibility” Constraints on the method’s return value and side effects. Relation between initial and final state of the method. Intuitively Expression that must hold at the exit from the method. Invariant Specifies caller’s responsibility at the entry to a method and implementation’s responsibility at the exit from a method. Valid states of class instances (values of fields). Intuitively Expression that must hold at the entry and exit of each method in the class. Class contract

What is ESC/Java2? A programming tool that attempts to find common run-time errors in Java programs by static analysis of the program text. ESC/Java versions are based around the Java Modeling Language (JML). – JML follows the design by contract paradigm. It is a specification language for Java programs, using Hoare style pre- and postconditions and invariants. The specifications are added as Java annotation comments to the Java program, which hence can be compiled with any Java compiler. – Users can control the amount and kinds of checking that ESC/Java2 performs by annotating their programs with specially formatted comments called pragmas.

ESC/Java2 - installation See – The txt file with information about installation. –

Demo 01: Fast exponentiation Demo 02: MyArray Demo 03: MySet ESC/Java2 – by example

Verificare şi Validarea Sistemelor Soft Tem ă Laborator 1 ESC/Java2 - Extended Static Checker for Java Dată primire laborator: Lab 1 Dată predare laborator: Lab 1 si Lab 2 A se vedea fişierul TemaLab01_ESCJava2.pdf