How to sort months in List<> in Spring boot

I have list of months, I am setting in the POJO class, While I am setting it, order is not getting sorted. I want to sort it. Sample data looks like -

My POJO Class -

public class SamplePojo {
   private static final long serialVersionUID = 1L;
   private String type;
   private String name;
   private Integer January;
   private Integer February;
   private Integer March;
   private Integer April;
   private Integer May;
   private Integer June;
}

ServiceImpl -

List<SamplePojo> sp = new ArrayList<SamplePojo>();
SamplePojo tp1 = new SamplePojo ();
        
        tp1.type("type");
        tp1.name("name");
        tp1.setJanuary(12);
        tp1.setFebruary(2);
        tp1.setMarch(33);
        tp1.setApril(0);
        tp1.setMay(0);
        tp1.setJune(0);
        tp1.setTotal(122);
        sp.add(tp1);

Unsorted data -

[
    {
        "type": "LLB",
        "name": "Working",
        "total": 0,
        "march": 33,
        "april": 0,
        "may": 0,
        "june": 0,
        "february": 2,
        "january": 12
    },
    {
        "type": "Engineer",
        "name": "Not Working",
        "total": 0,
        "march": 33,
        "april": 0,
        "may": 0,
        "june": 0,
        "february": 2,
        "january": 12
    }
]

Wanted to sort -

[
    {
        "type": "LLB",
        "name": "Working",
        "january": 11,
        "february": 2,
        "march": 3,
        "april": 3,
        "may": 0,
        "june": 0,
        "total": 0
    },
    {
        "type": "Engineer",
        "name": "Not Working",
        "january": 12,
        "february": 2,
        "march": 33,
        "april": 0,
        "may": 0,
        "june": 0,
        "total": 0
    }
]

How can I do this using Spring boot. I am new to this Spring boot and New to this stackoverflow. Can you please help me out.

CodePudding user response：

Try to sort using java 8 its not clear on question which fields need to sorted

 list.sort(Comparator.comparing(SamplePojo ::getType));// if sort by type

CodePudding user response：

The best way to do this is sorting from the repository by using Spring Data Repository query keywords by find all SampleEntity by following code.

@Repository
public interface SampleEntityRepository extends JpaRepository<SampleEntity, Long> {
    List<SampleEntity> findAllByOrderByJanuaryAsc();
}

But if you want to sort on the last layer to showing List of SamplePojo you can use stream and sorted by some criteria.

List<SamplePojo> lastList = sampleService.findAll();
lastList
    .stream()
    .sorted((sPojo1, sPojo2) -> sPojo1.getJanuary().compareTo(sPojo2.getJanuary()));