TreeSet of Custom Objects
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I created a TreeSet of custom objects (KCtrSrv) for a project I'm working on, and I'm trying to use .higher(KCtrSrv) and .lower(KCtrSrv). So a KCtrSrv Object would be passed in to compare to the other KCtrSrv objects that are already inside of the TreeSet. I would like to be able to isolate it to only look at the center field, is this possible?
**My tree contains three objects with centers 0.666, 2.0, 3.333 and Currently when I do tree.higher(newRequest) it returns 3.333. newRequest has values center = 0 and serverPosition = 0. It should be returning 0.666.
I'm not 100% positive how .higher() and .lower() operate, I've tried looking through JavaDocs however it hasn't really helped much. I've also thought about making a class for TreeSet and overriding .higher() and .lower(), however I wasn't quite sure where to begin the comparisons for that.
Any help would be greatly appreciated thanks!
My Object:
class KCtrSrv implements Comparable {
private double center;
private double serverPosition;
public KCtrSrv(double center, double serverPosition) {
this.center = center;
this.serverPosition = serverPosition;
}
private void setServerPosition(double position) {
this.serverPosition = position;
}
private double getServerPosition() {
return this.serverPosition;
}
private double getCenter() {
return this.center;
}
public int compareTo(KCtrSrv x) {
return (int) Math.abs(this.serverPosition - x.center);
}
}
java treeset
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
add a comment |
I created a TreeSet of custom objects (KCtrSrv) for a project I'm working on, and I'm trying to use .higher(KCtrSrv) and .lower(KCtrSrv). So a KCtrSrv Object would be passed in to compare to the other KCtrSrv objects that are already inside of the TreeSet. I would like to be able to isolate it to only look at the center field, is this possible?
**My tree contains three objects with centers 0.666, 2.0, 3.333 and Currently when I do tree.higher(newRequest) it returns 3.333. newRequest has values center = 0 and serverPosition = 0. It should be returning 0.666.
I'm not 100% positive how .higher() and .lower() operate, I've tried looking through JavaDocs however it hasn't really helped much. I've also thought about making a class for TreeSet and overriding .higher() and .lower(), however I wasn't quite sure where to begin the comparisons for that.
Any help would be greatly appreciated thanks!
My Object:
class KCtrSrv implements Comparable {
private double center;
private double serverPosition;
public KCtrSrv(double center, double serverPosition) {
this.center = center;
this.serverPosition = serverPosition;
}
private void setServerPosition(double position) {
this.serverPosition = position;
}
private double getServerPosition() {
return this.serverPosition;
}
private double getCenter() {
return this.center;
}
public int compareTo(KCtrSrv x) {
return (int) Math.abs(this.serverPosition - x.center);
}
}
java treeset
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
1
Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43
add a comment |
I created a TreeSet of custom objects (KCtrSrv) for a project I'm working on, and I'm trying to use .higher(KCtrSrv) and .lower(KCtrSrv). So a KCtrSrv Object would be passed in to compare to the other KCtrSrv objects that are already inside of the TreeSet. I would like to be able to isolate it to only look at the center field, is this possible?
**My tree contains three objects with centers 0.666, 2.0, 3.333 and Currently when I do tree.higher(newRequest) it returns 3.333. newRequest has values center = 0 and serverPosition = 0. It should be returning 0.666.
I'm not 100% positive how .higher() and .lower() operate, I've tried looking through JavaDocs however it hasn't really helped much. I've also thought about making a class for TreeSet and overriding .higher() and .lower(), however I wasn't quite sure where to begin the comparisons for that.
Any help would be greatly appreciated thanks!
My Object:
class KCtrSrv implements Comparable {
private double center;
private double serverPosition;
public KCtrSrv(double center, double serverPosition) {
this.center = center;
this.serverPosition = serverPosition;
}
private void setServerPosition(double position) {
this.serverPosition = position;
}
private double getServerPosition() {
return this.serverPosition;
}
private double getCenter() {
return this.center;
}
public int compareTo(KCtrSrv x) {
return (int) Math.abs(this.serverPosition - x.center);
}
}
java treeset
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
I created a TreeSet of custom objects (KCtrSrv) for a project I'm working on, and I'm trying to use .higher(KCtrSrv) and .lower(KCtrSrv). So a KCtrSrv Object would be passed in to compare to the other KCtrSrv objects that are already inside of the TreeSet. I would like to be able to isolate it to only look at the center field, is this possible?
**My tree contains three objects with centers 0.666, 2.0, 3.333 and Currently when I do tree.higher(newRequest) it returns 3.333. newRequest has values center = 0 and serverPosition = 0. It should be returning 0.666.
I'm not 100% positive how .higher() and .lower() operate, I've tried looking through JavaDocs however it hasn't really helped much. I've also thought about making a class for TreeSet and overriding .higher() and .lower(), however I wasn't quite sure where to begin the comparisons for that.
Any help would be greatly appreciated thanks!
My Object:
class KCtrSrv implements Comparable {
private double center;
private double serverPosition;
public KCtrSrv(double center, double serverPosition) {
this.center = center;
this.serverPosition = serverPosition;
}
private void setServerPosition(double position) {
this.serverPosition = position;
}
private double getServerPosition() {
return this.serverPosition;
}
private double getCenter() {
return this.center;
}
public int compareTo(KCtrSrv x) {
return (int) Math.abs(this.serverPosition - x.center);
}
}
java treeset
java treeset
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
edited Nov 29 '18 at 2:48
Nick Pav
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
asked Nov 29 '18 at 2:38
Nick PavNick Pav
34
34
1
Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43
add a comment |
1
Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43
1
1
Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43
Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43
add a comment |
1 Answer
1
active
oldest
votes
To make the treeset compare only based on center, you can write your compareto method like this:
public int compareTo(KCtrSrv x) {
return Double.compare(this.center, x.center);
}
On a side note, a.compareTo(b) is supposed to return a negative number when a is "less than" b. I don't see how an implementation that uses Math.abs could work
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changingimplements Comparabletoimplements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.
– Joni
Nov 29 '18 at 13:53
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
To make the treeset compare only based on center, you can write your compareto method like this:
public int compareTo(KCtrSrv x) {
return Double.compare(this.center, x.center);
}
On a side note, a.compareTo(b) is supposed to return a negative number when a is "less than" b. I don't see how an implementation that uses Math.abs could work
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changingimplements Comparabletoimplements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.
– Joni
Nov 29 '18 at 13:53
add a comment |
To make the treeset compare only based on center, you can write your compareto method like this:
public int compareTo(KCtrSrv x) {
return Double.compare(this.center, x.center);
}
On a side note, a.compareTo(b) is supposed to return a negative number when a is "less than" b. I don't see how an implementation that uses Math.abs could work
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changingimplements Comparabletoimplements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.
– Joni
Nov 29 '18 at 13:53
add a comment |
To make the treeset compare only based on center, you can write your compareto method like this:
public int compareTo(KCtrSrv x) {
return Double.compare(this.center, x.center);
}
On a side note, a.compareTo(b) is supposed to return a negative number when a is "less than" b. I don't see how an implementation that uses Math.abs could work
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
To make the treeset compare only based on center, you can write your compareto method like this:
public int compareTo(KCtrSrv x) {
return Double.compare(this.center, x.center);
}
On a side note, a.compareTo(b) is supposed to return a negative number when a is "less than" b. I don't see how an implementation that uses Math.abs could work
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
edited Nov 29 '18 at 3:07
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
answered Nov 29 '18 at 3:00
JoniJoni
77.8k999155
77.8k999155
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changingimplements Comparabletoimplements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.
– Joni
Nov 29 '18 at 13:53
add a comment |
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changingimplements Comparabletoimplements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.
– Joni
Nov 29 '18 at 13:53
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
Would I then have to override compareTo(Object o) in order for that comparison to happen? I don't seem to be able to because I'm passing in KCtrSrv and not an Object..
– Nick Pav
Nov 29 '18 at 3:10
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
I changed the parameter to Object x and casted it to KCtrSrv within the method and I was then able to override, and now the comparison seems to be working. Thank you so much!
– Nick Pav
Nov 29 '18 at 3:14
Glad you could make it work. An alternative to what you did is changing
implements Comparable to implements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.– Joni
Nov 29 '18 at 13:53
Glad you could make it work. An alternative to what you did is changing
implements Comparable to implements Comparable<KCtrSrv>. With the first one you're saying "objects of this class can be compared with anything that exists", with the second you'd be restricting it to objects of the same class and wouldn't need to cast.– Joni
Nov 29 '18 at 13:53
add a comment |
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Please post your code as text in the question, not as a linked screenshot
– Joni
Nov 29 '18 at 2:43