• Calling Conventions:
  • A calling convention is a protocol governing the calling of and returning from "subprograms"
• Some Observations:
  • A calling convention needs to consider information that needs to be saved/restored, parameters, return values, and the transfer of control
  • Many such protocols are possible
• An Abstraction:
  • We can ignore the details and consider an abstract activation record (or invocation record or stack frame)

• StackTraceElement :
  • An encapsulation of a stack frame
• Organization:
  • StackFrameElement objects are organized into a last-in, first-out (LIFO) "collection" (called a stack)
  • Each StackFrameElement object (except, perhaps, the top-most) represents a method invocation
  • The top-most StackFrameElement object can represent an execution point (e.g., the point at which a Throwable was created)

• Recall:
  • When an exception is never caught (e.g., re-thrown by every method including main()), the program terminates and a message is printed
• The Contents of the Message:
  • The LIFO "collection" of StackFrameElement objects

• Obtaining a Stack Trace:
  • The static getStackTrace() method in the Throwable class will return the stack trace (i.e., the LIFO StackTraceElement[]) that was created when the Throwable was created
  • The getStackTrace() method belonging to a Thread object returns its current stack trace and the current Thread (loosely, the current sequence of instructions) can be obtained using the static currentThread() method in the Thread class
• Useful Methods:
  • getClassName()
  • getFileName()
  • getLineNumber()
  • getMethodName()

The Stack Trace:

  OverdraftAccount.amountAvailable(OverdraftAccount.java:20)
  Account.withdraw(Account.java:59)
  Driver.main(Driver.java:36)