Recoverable applications - Software Development Case Studies in Java - page 495

private String when # null ; // "before" or "after"
private Class[] parameters # null ;
// the list of parameter types
private Object[] arguments # null ;
// the list of argument values
. . .
public Entry(Trackable target, String methodName,
Class[] parameters, Object[] arguments) {
this .methodName # methodName;
this .targetRef # Tracker.getObjectRef(target);
this .parameters # parameters;
this .arguments # arguments;
}
// use reflection to invoke a method on a target object
public Object invoke(Object target) {
Object result # null ;
try {
Class c # target.getClass();
Method m # c.getMethod
( this .methodName, this .parameters);
result # m.invoke(target, this .arguments);
} catch (Exception e) { System.out.println(e); }
return result;
}
}
Class Tracker has two new member variables that are used to enable and
disable the tracking process and to select the tracking type (logical or
physical).
public final class Tracker {
...
private static boolean tracking # false ;
private static boolean logicalRecording # false ;
public static void setLogicalRecording( boolean logical) {
logicalRecording # logical;
}
public static boolean isLogicalRecording() {
return logicalRecording;
}
// opens the tracking log
public static void startTracking() {
try {
if (logicalRecording)
outputFile # new FileOutputStream
("trackerLogical.log");