Join Point Interfaces

AbstractGrammar.java

JPITypeDecl : TypeDecl ::=
ReturnType:Access Parameters:ParameterDeclaration* Exception:Access*; SuperTypeName:Access SuperArgumentName:Access*;
ExhibitBodyDecl : BodyDecl ::=
ReturnType:Access JPIName:Access Parameter:ParameterDeclaration* Pointcut:PointcutExpr;
CJPAdviceDecl : AdviceDecl;
CJPPointcutExpr: PointcutExpr;
CJPBeforeSpec : BeforeSpec ::= JPIName:Access;
/*the rest of the advice specifications are omitted from this listing*/

CheckingOutJPI.aj

jpi void CheckingOut(double price, Customer cus);

Discount.aj

aspect Discount {
  pointcut CheckingOut(double pPrice, Customer pCustomer):
    execution(* ShoppingSession.checkOut(..))
    && args(*,pPrice,*,pCustomer);

  void around (double aPrice, Customer aCustomer) : CheckingOut(aPrice, aCustomer) {
    double factor = aCustomer.hasBirthdayToday() ? 0.95 : 1;
    proceed(aPrice*factor, aCustomer);
  }
}

DiscountAspectWithJPI.aj

aspect Discount {
  void around CheckingOut(double price, Customer c) {
    double factor = c.hasBirthday()? 0.95 : 1;
    proceed(price*factor, c); }
}

JPIProductions.java

TypeDecl type_declaration = jpi_declaration.d {:return d; :};
BodyDecl class_member_declaration = exhibit_declaration.d {: return d; :};
BodyDecl aspect_body_declaration = cjp_advice_declaration.d {: return d; :};

ModularTypeChecking.java

public static void checkingOut() throws Exception {
  throw new Exception();
}

void around(): call(* checkingOut(..) ) {
  proceed();
  //throw new Exception();
}

NewKeywords.java

public void initLexerKeywords(AbcLexer lexer) {
  lexer.addGlobalKeyword(
    "jpi", //"exhibits"
    new LexerAction_c(
      new Integer(Terminals.JPI), //Terminals.EXHIBITS
      new Integer(lexer.pointcut_state())
    )
  );
}

ShoppingSession.java

class ShoppingSession {
  ShoppingCart cart;
  double totalValue;
  
  void checkOut(Item item, double price, int amount, Customer cus){
    cart.add(item, amount); //fill shopping cart cus.charge(price); //charge customer
    totalValue += price; //increase total value of session
  }
}

ShoppingSessionWithJPI.java

class ShoppingSession {
  exhibits void CheckingOut(double price, Customer c):
    execution(* checkOut(..))
    && args(*, price, *, c);

  void checkOut(Item item, double price, int amount, Customer cus){
    cart.add(item, amount); //fill shopping cart cus.charge(price); //charge customer
    totalValue += price; //increase total value of session
  }
}