I want to use the pattern Chain of Responsibility to check if a location (Latitude and Longitude) is on a distance. For this purpose I got a boolean which should be true if location is on distance and false if not. Before the pattern - my code looked like this:
public static boolean OnDistance(MyLocation a, MyLocation b, MyLocation queryPoint) {
// wenn x von a kleiner ist als b´s
if (a.mLongitude < b.mLongitude) {
// nd query dazwischen liegt
if (b.mLongitude >= queryPoint.mLongitude && queryPoint.mLongitude >= a.mLongitude) {
if (a.mLatitude > b.mLatitude) {
if (queryPoint.mLatitude <= a.mLatitude && queryPoint.mLatitude >= b.mLatitude) {
System.out.println("ja!");
return true;
}
}
if (a.mLatitude < b.mLatitude) {
if (queryPoint.mLatitude >= a.mLatitude && queryPoint.mLatitude <= b.mLatitude) {
System.out.println("ja!");
return true;
}
}
}
{
}
}
// wenn x von b kleiner ist als a´s
if (b.mLongitude < a.mLongitude) {
if (queryPoint.mLongitude >= b.mLongitude && queryPoint.mLongitude <= a.mLongitude) {
if (a.mLatitude > b.mLatitude) {
if (queryPoint.mLatitude <= a.mLatitude && queryPoint.mLatitude >= b.mLatitude) {
System.out.println("ja!");
return true;
}
}
if (a.mLatitude < b.mLatitude) {
if (queryPoint.mLatitude <= b.mLatitude && queryPoint.mLatitude >= a.mLatitude) {
System.out.println("ja!");
return true;
}
}
}
}
System.out.println("leider nichts geworden! . lauf weiter!!!!");
return false;
}
part of my Chain of Responsibility code (I got four classes like this one):
public boolean check(MyLocation a, MyLocation b, MyLocation queryPoint) {
// TODO Auto-generated method stub
if ((a.mLongitude < b.mLongitude)
&& (b.mLongitude >= queryPoint.mLongitude && queryPoint.mLongitude >= a.mLongitude)
&& (a.mLatitude > b.mLatitude)
&& (queryPoint.mLatitude <= a.mLatitude && queryPoint.mLatitude >= b.mLatitude)) {
System.out.println("ja, gerne!");
onDistance = true;
return true;
}
else {
onDistance = false;
System.out.println("weiter, lauf doch weiter");
nextInChain.check(a, b, queryPoint);
}
return false;
}}
the code works but because of the "boolean return" it walks through the chain and after that it walks the complete way back to execute this returns.
My Question: First of all - is Chain of Responsibility a suitable way to "replace" this if-statments. And is there a way to stop the chain go back all the way to execute all the returns or rather what can I use instead of this boolean?
Thanks!
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