Sort a set in Java
Framework used: Spring
ORM used: Hibernate
I have two classes
class BatchExceptionDetails{
...
private Set<BatchExceptionComments> batchExceptionComments;
}
class BatchExceptionComments implements Comparable<BatchExceptionComments>{
...
@Override
public int compareTo(BatchExceptionComments o) {
// TODO Auto-generated method stub
return this.getAddedOn().compareTo(o.getAddedOn());
}
}
They are mapped with one to many mapping.
There is a set of BatchExceptionComments in BatchExceptionDetails.
I want to sort the set on the basis of Date. BatchExcpetionComment has an attribute of type java.util.Date i.e. addedOn. I want the latest comment to be the first element of set.
The set I am receiving is not sorted. Will you please guide me where I am going wrong.
Thanks in advance
java spring hibernate sorting collections
asked Nov 22 '18 at 7:44
AyushAyush
618
|
show 4 more comments
Framework used: Spring
ORM used: Hibernate
I have two classes
class BatchExceptionDetails{
...
private Set<BatchExceptionComments> batchExceptionComments;
}
class BatchExceptionComments implements Comparable<BatchExceptionComments>{
...
@Override
public int compareTo(BatchExceptionComments o) {
// TODO Auto-generated method stub
return this.getAddedOn().compareTo(o.getAddedOn());
}
}
They are mapped with one to many mapping.
There is a set of BatchExceptionComments in BatchExceptionDetails.
I want to sort the set on the basis of Date. BatchExcpetionComment has an attribute of type java.util.Date i.e. addedOn. I want the latest comment to be the first element of set.
The set I am receiving is not sorted. Will you please guide me where I am going wrong.
Thanks in advance
java spring hibernate sorting collections
asked Nov 22 '18 at 7:44
AyushAyush
618
Are you using aSortedSet? Or some other type ofSet?
– Joe C
Nov 22 '18 at 7:45
Collections.sort(batchExceptionComments);
– Lorelorelore
Nov 22 '18 at 7:46
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
2
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
2
You can't be using justSet, becauseSetis an interface. What implementation ofSetare you using?
– Joe C
Nov 22 '18 at 7:50
|
show 4 more comments
Framework used: Spring
ORM used: Hibernate
I have two classes
class BatchExceptionDetails{
...
private Set<BatchExceptionComments> batchExceptionComments;
}
class BatchExceptionComments implements Comparable<BatchExceptionComments>{
...
@Override
public int compareTo(BatchExceptionComments o) {
// TODO Auto-generated method stub
return this.getAddedOn().compareTo(o.getAddedOn());
}
}
They are mapped with one to many mapping.
There is a set of BatchExceptionComments in BatchExceptionDetails.
I want to sort the set on the basis of Date. BatchExcpetionComment has an attribute of type java.util.Date i.e. addedOn. I want the latest comment to be the first element of set.
The set I am receiving is not sorted. Will you please guide me where I am going wrong.
Thanks in advance
java spring hibernate sorting collections
asked Nov 22 '18 at 7:44
AyushAyush
618
Framework used: Spring
ORM used: Hibernate
I have two classes
class BatchExceptionDetails{
...
private Set<BatchExceptionComments> batchExceptionComments;
}
class BatchExceptionComments implements Comparable<BatchExceptionComments>{
...
@Override
public int compareTo(BatchExceptionComments o) {
// TODO Auto-generated method stub
return this.getAddedOn().compareTo(o.getAddedOn());
}
}
They are mapped with one to many mapping.
There is a set of BatchExceptionComments in BatchExceptionDetails.
I want to sort the set on the basis of Date. BatchExcpetionComment has an attribute of type java.util.Date i.e. addedOn. I want the latest comment to be the first element of set.
The set I am receiving is not sorted. Will you please guide me where I am going wrong.
Thanks in advance
java spring hibernate sorting collections
java spring hibernate sorting collections
asked Nov 22 '18 at 7:44
AyushAyush
618
asked Nov 22 '18 at 7:44
AyushAyush
618
asked Nov 22 '18 at 7:44
AyushAyush
618
asked Nov 22 '18 at 7:44
AyushAyush
618
asked Nov 22 '18 at 7:44
AyushAyush
618
618
Are you using aSortedSet? Or some other type ofSet?
– Joe C
Nov 22 '18 at 7:45
Collections.sort(batchExceptionComments);
– Lorelorelore
Nov 22 '18 at 7:46
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
2
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
2
You can't be using justSet, becauseSetis an interface. What implementation ofSetare you using?
– Joe C
Nov 22 '18 at 7:50
|
show 4 more comments
Are you using aSortedSet? Or some other type ofSet?
– Joe C
Nov 22 '18 at 7:45
Collections.sort(batchExceptionComments);
– Lorelorelore
Nov 22 '18 at 7:46
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
2
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
2
You can't be using justSet, becauseSetis an interface. What implementation ofSetare you using?
– Joe C
Nov 22 '18 at 7:50
Are you using a
SortedSet? Or some other type of Set?– Joe C
Nov 22 '18 at 7:45
Are you using a
SortedSet? Or some other type of Set?– Joe C
Nov 22 '18 at 7:45
Collections.sort(batchExceptionComments);– Lorelorelore
Nov 22 '18 at 7:46
Collections.sort(batchExceptionComments);– Lorelorelore
Nov 22 '18 at 7:46
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
2
2
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
2
2
You can't be using just
Set, because Set is an interface. What implementation of Set are you using?– Joe C
Nov 22 '18 at 7:50
You can't be using just
Set, because Set is an interface. What implementation of Set are you using?– Joe C
Nov 22 '18 at 7:50
|
show 4 more comments
2 Answers
2
active
oldest
votes
Set is an interface, so it is not possible to establish if it is sortable or not. You have to use the correct implementation, like TreeSet. If you want to
emphasize that it is a sorted set, you should use the SortedSet interface. TreeSet implements SortedSet.
Alternatively you can use a List and then you can sort it using Collections.sort.
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type asSortedSetinstead ofSetshould work though.
– Robby Cornelissen
Nov 22 '18 at 7:59
1
No need to initialize it. Hibernate will automatically initialize it with its ownSortedSetimplementation.
– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
|
show 2 more comments
After some goofing around I found a solution.
I just declared the set
private Set<BatchExceptionComments> batchExceptionComments;
Instead of using Comparable I used Order By to arrange the set.
<set name="batchExceptionComments" table="BATCH_EXCEPTION_COMMENTS"
inverse="true" fetch="select" lazy="false" order-by="commentId">
<key>
<column name="EXCEPTION_ID" not-null="true" />
</key>
<one-to-many class="com.beans.BatchExceptionComments" />
</set>
I believe ordering by Id will be better.
P.S. I am using hbm.xml instead of annotation
answered Nov 22 '18 at 14:37
AyushAyush
618
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Set is an interface, so it is not possible to establish if it is sortable or not. You have to use the correct implementation, like TreeSet. If you want to
emphasize that it is a sorted set, you should use the SortedSet interface. TreeSet implements SortedSet.
Alternatively you can use a List and then you can sort it using Collections.sort.
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type asSortedSetinstead ofSetshould work though.
– Robby Cornelissen
Nov 22 '18 at 7:59
1
No need to initialize it. Hibernate will automatically initialize it with its ownSortedSetimplementation.
– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
|
show 2 more comments
Set is an interface, so it is not possible to establish if it is sortable or not. You have to use the correct implementation, like TreeSet. If you want to
emphasize that it is a sorted set, you should use the SortedSet interface. TreeSet implements SortedSet.
Alternatively you can use a List and then you can sort it using Collections.sort.
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type asSortedSetinstead ofSetshould work though.
– Robby Cornelissen
Nov 22 '18 at 7:59
1
No need to initialize it. Hibernate will automatically initialize it with its ownSortedSetimplementation.
– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
|
show 2 more comments
Set is an interface, so it is not possible to establish if it is sortable or not. You have to use the correct implementation, like TreeSet. If you want to
emphasize that it is a sorted set, you should use the SortedSet interface. TreeSet implements SortedSet.
Alternatively you can use a List and then you can sort it using Collections.sort.
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
Set is an interface, so it is not possible to establish if it is sortable or not. You have to use the correct implementation, like TreeSet. If you want to
emphasize that it is a sorted set, you should use the SortedSet interface. TreeSet implements SortedSet.
Alternatively you can use a List and then you can sort it using Collections.sort.
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
answered Nov 22 '18 at 7:53
LoreloreloreLorelorelore
2,01561327
2,01561327
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type asSortedSetinstead ofSetshould work though.
– Robby Cornelissen
Nov 22 '18 at 7:59
1
No need to initialize it. Hibernate will automatically initialize it with its ownSortedSetimplementation.
– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
|
show 2 more comments
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type asSortedSetinstead ofSetshould work though.
– Robby Cornelissen
Nov 22 '18 at 7:59
1
No need to initialize it. Hibernate will automatically initialize it with its ownSortedSetimplementation.
– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
Can I use other collections instead of Set ? I am in assumption that if we are using Spring then we have to use Set for Containment.
– Ayush
Nov 22 '18 at 7:58
3
3
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type as
SortedSet instead of Set should work though.– Robby Cornelissen
Nov 22 '18 at 7:59
The problem is that Hibernate requires collections to be specified as an interface type. In terms of implementation classes, it uses its own to support things like lazy loading. Specifying the type as
SortedSet instead of Set should work though.– Robby Cornelissen
Nov 22 '18 at 7:59
1
1
No need to initialize it. Hibernate will automatically initialize it with its own
SortedSet implementation.– Robby Cornelissen
Nov 22 '18 at 8:04
No need to initialize it. Hibernate will automatically initialize it with its own
SortedSet implementation.– Robby Cornelissen
Nov 22 '18 at 8:04
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, I used SortedSet and I am getting an exception IllegalArgumentException occurred while calling setter for property [combeans.BatchExceptionDetails.batchExceptionComments (expected type = java.util.SortedSet)];
– Ayush
Nov 22 '18 at 8:15
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
@RobbyCornelissen, my setter method is public void setBatchExceptionComments( SortedSet<BatchExceptionComments> batchExceptionComments) { this.batchExceptionComments = batchExceptionComments; }
– Ayush
Nov 22 '18 at 8:17
|
show 2 more comments
After some goofing around I found a solution.
I just declared the set
private Set<BatchExceptionComments> batchExceptionComments;
Instead of using Comparable I used Order By to arrange the set.
<set name="batchExceptionComments" table="BATCH_EXCEPTION_COMMENTS"
inverse="true" fetch="select" lazy="false" order-by="commentId">
<key>
<column name="EXCEPTION_ID" not-null="true" />
</key>
<one-to-many class="com.beans.BatchExceptionComments" />
</set>
I believe ordering by Id will be better.
P.S. I am using hbm.xml instead of annotation
answered Nov 22 '18 at 14:37
AyushAyush
618
add a comment |
After some goofing around I found a solution.
I just declared the set
private Set<BatchExceptionComments> batchExceptionComments;
Instead of using Comparable I used Order By to arrange the set.
<set name="batchExceptionComments" table="BATCH_EXCEPTION_COMMENTS"
inverse="true" fetch="select" lazy="false" order-by="commentId">
<key>
<column name="EXCEPTION_ID" not-null="true" />
</key>
<one-to-many class="com.beans.BatchExceptionComments" />
</set>
I believe ordering by Id will be better.
P.S. I am using hbm.xml instead of annotation
answered Nov 22 '18 at 14:37
AyushAyush
618
add a comment |
After some goofing around I found a solution.
I just declared the set
private Set<BatchExceptionComments> batchExceptionComments;
Instead of using Comparable I used Order By to arrange the set.
<set name="batchExceptionComments" table="BATCH_EXCEPTION_COMMENTS"
inverse="true" fetch="select" lazy="false" order-by="commentId">
<key>
<column name="EXCEPTION_ID" not-null="true" />
</key>
<one-to-many class="com.beans.BatchExceptionComments" />
</set>
I believe ordering by Id will be better.
P.S. I am using hbm.xml instead of annotation
answered Nov 22 '18 at 14:37
AyushAyush
618
After some goofing around I found a solution.
I just declared the set
private Set<BatchExceptionComments> batchExceptionComments;
Instead of using Comparable I used Order By to arrange the set.
<set name="batchExceptionComments" table="BATCH_EXCEPTION_COMMENTS"
inverse="true" fetch="select" lazy="false" order-by="commentId">
<key>
<column name="EXCEPTION_ID" not-null="true" />
</key>
<one-to-many class="com.beans.BatchExceptionComments" />
</set>
I believe ordering by Id will be better.
P.S. I am using hbm.xml instead of annotation
answered Nov 22 '18 at 14:37
AyushAyush
618
answered Nov 22 '18 at 14:37
AyushAyush
618
answered Nov 22 '18 at 14:37
AyushAyush
618
answered Nov 22 '18 at 14:37
AyushAyush
618
618
add a comment |
add a comment |
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Are you using a
SortedSet? Or some other type ofSet?– Joe C
Nov 22 '18 at 7:45
Collections.sort(batchExceptionComments);– Lorelorelore
Nov 22 '18 at 7:46
@Lorelorelore That's only available for lists, not for sets.
– Joe C
Nov 22 '18 at 7:48
2
Sets are unsorted. Use a list instead.
– Robby Cornelissen
Nov 22 '18 at 7:49
2
You can't be using just
Set, becauseSetis an interface. What implementation ofSetare you using?– Joe C
Nov 22 '18 at 7:50