如何根据spring数据jpa中的条件指定append

Question

I am creating a spring boot project and working on spring data jpa and currently I am using custom query to fetch data from db based on users selection and this is my page where user can select option based on their condition https://i.imgur.com/coO3BCJ.png

So, I googled it and found we can use specification but as I am very new to specification, so, I used specification and I want that based on users choice, it should keep adding specification, so, this is my conditional specification...

Specification<UserDetails> specification = 
Specification.where(UserDetailsSpecification
.isAgeBetween(customSearch.getFromage(), customSearch.getToage()));

if(!customSearch.getManglik().isBlank()) {               
 specification.and(UserDetailsSpecification.isManglik
 (customSearch.getManglik())); 
}
if(!customSearch.getMaritalStatus().isBlank()) {                 
specification.and(UserDetailsSpecification
.hasMaritalStatus(customSearch.getMaritalStatus())); 
}
if(!customSearch.getReligion().isBlank()) {              
specification.and(UserDetailsSpecification.hasReligion
(customSearch.getReligion())); 
}
if(!customSearch.getCaste().isBlank()) {                 
specification.and(UserDetailsSpecification.hasCaste
(customSearch.getCaste())); 
}
  if(!customSearch.getLocation().isBlank()) {                
  specification.and(UserDetailsSpecification.hasLocation
(customSearch.getLocation())); 
}

listOfCustomSearch=userDetailsRepository
.findAll(specification, pageable);
List<UserDetails> listOfAllSearchedUsers = listOfCustomSearch.getContent();

but it is not appending the specification and just filtering the data based on only

Specification<UserDetails> specification = Specification.where(UserDetailsSpecification
                .isAgeBetween(customSearch.getFromage(), customSearch.getToage()));

so, based on users selection, so, my final query should be something like this(If user has selected all fields):

Specification<UserDetails> specification = Specification.where(UserDetailsSpecification
.isAgeBetween(customSearch.getFromage(), customSearch.getToage())
.and(UserDetailsSpecification.isManglik(customSearch.getManglik())                  .and(UserDetailsSpecification.hasMaritalStatus(customSearch.getMaritalStatus()))                    .and(UserDetailsSpecification.hasReligion(customSearch.getReligion()))
.and(UserDetailsSpecification.hasCaste(customSearch.getCaste()))
.and(UserDetailsSpecification.hasLocation(customSearch.getLocation()))))

But suppose if user has selected only let suppose 3 or 4 fields, so, my final specification should be something like below:(This specification should be completely depends upon user selection)

Specification<UserDetails> specification = Specification.where(UserDetailsSpecification
.isAgeBetween(customSearch.getFromage(), customSearch.getToage())
.and(UserDetailsSpecification.isManglik(customSearch.getManglik())                  
.and(UserDetailsSpecification.hasLocation(customSearch.getLocation()))))

Currently it is not appending specification based on users selection, so, please help me in adding specification based on users selections

Answer 1

Finally, I found the solution and we can create customized specification like this below:

public static Specification<UserDetails> getSpecs(String gender, int fromAge, int toAge, String manglikStatus, String maritalStatus, String religion, String caste, String location){
    Specification<UserDetails> spec = null;
    Specification<UserDetails> temp = null;
    
    if(!gender.isBlank() && !gender.isEmpty() && gender!=null && !gender.contains("$")) {
        spec = getSpecsForGenderDetails(gender);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    
    if(fromAge!=0 || toAge!=0) {
        spec = isAgeBetween(fromAge, toAge);
        temp = spec!=null?Specification.where(spec).and(temp):temp;
    }
    if(!manglikStatus.isBlank() && !manglikStatus.isEmpty() && manglikStatus!=null && !manglikStatus.contains("$")) {
        spec = isManglik(manglikStatus);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    if(!maritalStatus.isBlank() && !maritalStatus.isEmpty() && maritalStatus!=null && !maritalStatus.contains("$")) {
        spec = hasMaritalStatus(maritalStatus);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    if(!religion.isBlank() && !religion.isEmpty() && religion!=null && !religion.contains("$")) {
        spec = hasReligion(religion);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    if(!caste.isBlank() && !caste.isEmpty() && caste!=null && !caste.equalsIgnoreCase("select") && !caste.contains("$")) {
        spec = hasCaste(caste);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    if(!location.isBlank() && !location.isEmpty() && location!=null && !location.contains("$")) {
        spec = hasLocation(location);
        temp = spec!=null?Specification.where(spec).and(temp):temp; 
    }
    return temp;
    
}

And based on that we can define our method like this:

private static Specification<UserDetails> getSpecsForGenderDetails(String gender) {
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.equal(root.get("gender"),gender);
    });
}

private static Specification<UserDetails> isAgeBetween(int fromAge, int toAge){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.between(root.get("age"), fromAge, toAge);
    });
}

private static Specification<UserDetails> isManglik(String manglikStatus){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.like(criteriaBuilder.lower(root.get("manglikStatus")),"%" +manglikStatus.toLowerCase() +"%");            
    });
}

private static Specification<UserDetails> hasMaritalStatus(String maritalStatus){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.like(criteriaBuilder.lower(root.get("maritalStatus")),"%" +maritalStatus.toLowerCase() +"%");            
    });
}
private static Specification<UserDetails> hasReligion(String religion){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.like(criteriaBuilder.lower(root.get("religion")),"%" +religion.toLowerCase() +"%");
    });
}
private static Specification<UserDetails> hasCaste(String caste){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.like(criteriaBuilder.lower(root.get("caste")),"%" +caste.toLowerCase() +"%");
    });
}
private static Specification<UserDetails> hasLocation(String presentState){
    return ((root, query, criteriaBuilder) -> {
        return criteriaBuilder.like(criteriaBuilder.lower(root.get("presentState")),"%" +presentState.toLowerCase() +"%");
    });
}