Alrighty: I've been banging my head on a wall the whole day and can't solve this issue. I am trying to find an ID in an object list which is like 3 levels down the hierarchy with the Java stream API. I know how to do it with a for loop but I need to get it with a stream.
JSON response is:
{
"NumberOfOwners": 1,
"CurrentPage": 1,
"TotalItems": 1,
"TotalPages": 1,
"PageSize": 1,
"PageItems": [
{
"Id": 1560,
"Title": "PlsWrk",
"IsSubmitted": true,
"Owner": {
"Branch": null,
"Position": null,
"Id": null,
"FirstName": null,
"LastName": null,
"ParentName": null,
"Gender": null,
"Image": null,
"LoginStatusId": 0,
"EmployeeStatus": 0,
"CompanyName": null,
"IsSubcontractor": false
},
"KeyResults": [
{
"Id": 5032,
"Title": "asdf1",
"OverallStatus": 2,
"MonthKeyResults": [
{
"Id": 12484,
"Month": 9,
"Status": 3,
"Progress": "REaplace1"
},
{
"Id": 12483,
"Month": 8,
"Status": 3,
"Progress": "sadf4"
},
{
"Id": 12482,
"Month": 7,
"Status": 1,
"Progress": "On Track1"
}
]
},
{
"Id": 5033,
"Title": "asdf2",
"OverallStatus": 1,
"MonthKeyResults": [
{
"Id": 12485,
"Month": 7,
"Status": 2,
"Progress": "Recovery2"
},
{
"Id": 12487,
"Month": 9,
"Status": 2,
"Progress": "asdfreas"
},
{
"Id": 12486,
"Month": 8,
"Status": 1,
"Progress": "asdf5"
}
]
},
{
"Id": 5034,
"Title": "asdf3",
"OverallStatus": 2,
"MonthKeyResults": [
{
"Id": 12490,
"Month": 9,
"Status": 1,
"Progress": "asdafa"
},
{
"Id": 12489,
"Month": 8,
"Status": 2,
"Progress": "asdf6"
},
{
"Id": 12488,
"Month": 7,
"Status": 3,
"Progress": "Replace3"
}
]
}
]
}
]
}
Precisely I want stream to return the MonthyKeyResult object with a specific ID.
At the moment, I am here:
public static MonthKeyResults getOkrMonthlyProgressById(PageItems okr, Integer monthlyProgressId){
//here i get KeyResults object list
List<KeyResults> keyResult = okr.getKeyResults().stream().collect(Collectors.toList());
//and now I am trying to get all MonthKeyResults
//objects but I not doing it right
List<MonthKeyResults> monthKeyResults = keyResult.stream().
filter(monthKeyResult -> monthKeyResult.
getMonthKeyResults().
stream().collect(Collectors.toList()));
//and then I am thinking of going through the monthKeyResults
//list with stream and finding Id I need and returning that
//whole object with something like this
MonthKeyResults mKeyResults = monthKeyResults.stream().filter(id -> id.getId().
equals(monthlyProgressId)).findAny().orElse(null);
return mKeyResult;
}
I've got one more question:
I've separated getting the final object as you see in 3 streams; is it possible to get it in one go or you need to separate the objects like this and go through them separately?
Probably you're looking for something like:
return okr.getKeyResults().stream()
.flatMap(keyResult -> keyResult.getMonthKeyResults().stream())
.filter(monthKeyResult -> monthKeyResult.getId().equals(monthlyProgressId))
.findAny()
.orElse(null);