REST Query Language - Операции расширенного поиска

public enum SearchOperation {
    EQUALITY, NEGATION, GREATER_THAN, LESS_THAN, LIKE, STARTS_WITH, ENDS_WITH, CONTAINS;

    public static final String[] SIMPLE_OPERATION_SET = { ":", "!", ">", "<", "~" };

    public static SearchOperation getSimpleOperation(char input) {
        switch (input) {
        case ':':
            return EQUALITY;
        case '!':
            return NEGATION;
        case '>':
            return GREATER_THAN;
        case '<':
            return LESS_THAN;
        case '~':
            return LIKE;
        default:
            return null;
        }
    }
}

public class SearchCriteria {
    private String key;
    private SearchOperation operation;
    private Object value;
}

public class UserSpecification implements Specification {

    private SearchCriteria criteria;

    @Override
    public Predicate toPredicate(
      Root root, CriteriaQuery query, CriteriaBuilder builder) {

        switch (criteria.getOperation()) {
        case EQUALITY:
            return builder.equal(root.get(criteria.getKey()), criteria.getValue());
        case NEGATION:
            return builder.notEqual(root.get(criteria.getKey()), criteria.getValue());
        case GREATER_THAN:
            return builder.greaterThan(root. get(
              criteria.getKey()), criteria.getValue().toString());
        case LESS_THAN:
            return builder.lessThan(root. get(
              criteria.getKey()), criteria.getValue().toString());
        case LIKE:
            return builder.like(root. get(
              criteria.getKey()), criteria.getValue().toString());
        case STARTS_WITH:
            return builder.like(root. get(criteria.getKey()), criteria.getValue() + "%");
        case ENDS_WITH:
            return builder.like(root. get(criteria.getKey()), "%" + criteria.getValue());
        case CONTAINS:
            return builder.like(root. get(
              criteria.getKey()), "%" + criteria.getValue() + "%");
        default:
            return null;
        }
    }
}

public class UserSpecificationsBuilder {

    private List params;

    public UserSpecificationsBuilder with(
      String key, String operation, Object value, String prefix, String suffix) {

        SearchOperation op = SearchOperation.getSimpleOperation(operation.charAt(0));
        if (op != null) {
            if (op == SearchOperation.EQUALITY) {
                boolean startWithAsterisk = prefix.contains("*");
                boolean endWithAsterisk = suffix.contains("*");

                if (startWithAsterisk && endWithAsterisk) {
                    op = SearchOperation.CONTAINS;
                } else if (startWithAsterisk) {
                    op = SearchOperation.ENDS_WITH;
                } else if (endWithAsterisk) {
                    op = SearchOperation.STARTS_WITH;
                }
            }
            params.add(new SearchCriteria(key, op, value));
        }
        return this;
    }

    public Specification build() {
        if (params.size() == 0) {
            return null;
        }

        Specification result = new UserSpecification(params.get(0));

        for (int i = 1; i < params.size(); i++) {
            result = params.get(i).isOrPredicate()
              ? Specification.where(result).or(new UserSpecification(params.get(i)))
              : Specification.where(result).and(new UserSpecification(params.get(i)));
        }

        return result;
    }
}

@RequestMapping(method = RequestMethod.GET, value = "/users")
@ResponseBody
public List findAllBySpecification(@RequestParam(value = "search") String search) {
    UserSpecificationsBuilder builder = new UserSpecificationsBuilder();
    String operationSetExper = Joiner.on("|").join(SearchOperation.SIMPLE_OPERATION_SET);
    Pattern pattern = Pattern.compile(
      "(\\w+?)(" + operationSetExper + ")(\p{Punct}?)(\\w+?)(\p{Punct}?),");
    Matcher matcher = pattern.matcher(search + ",");
    while (matcher.find()) {
        builder.with(
          matcher.group(1),
          matcher.group(2),
          matcher.group(4),
          matcher.group(3),
          matcher.group(5));
    }

    Specification spec = builder.build();
    return dao.findAll(spec);
}

http://localhost:8080/users?search=firstName:jo*,age<25

[{
    "id":1,
    "firstName":"john",
    "lastName":"doe",
    "email":"[email protected]",
    "age":24
}]

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(
  classes = { ConfigTest.class, PersistenceConfig.class },
  loader = AnnotationConfigContextLoader.class)
@ActiveProfiles("test")
public class JPASpecificationLiveTest {

    @Autowired
    private UserRepository repository;

    private User userJohn;
    private User userTom;

    private final String URL_PREFIX = "http://localhost:8080/users?search=";

    @Before
    public void init() {
        userJohn = new User();
        userJohn.setFirstName("John");
        userJohn.setLastName("Doe");
        userJohn.setEmail("[email protected]");
        userJohn.setAge(22);
        repository.save(userJohn);

        userTom = new User();
        userTom.setFirstName("Tom");
        userTom.setLastName("Doe");
        userTom.setEmail("[email protected]");
        userTom.setAge(26);
        repository.save(userTom);
    }

    private RequestSpecification givenAuth() {
        return RestAssured.given().auth()
                                  .preemptive()
                                  .basic("username", "password");
    }
}