A collection of utility classes and abstractions for Spring Boot projects, providing common patterns for service layers, repository specifications, and JSON deserialization.
✨ Spring Boot 2.7.x & 3.x Compatible | ☕ Java 11+ (Spring Boot 2) / Java 17+ (Spring Boot 3)
- 🎯 Abstract Service Layer - Base implementation for CRUD operations with Spring Data JPA
- 🔍 Specification Builders - Fluent API for building JPA Specifications
- 📄 Pagination Support - Simple PageData wrapper for paginated results
- 📅 JSON Deserializers - Custom deserializers for LocalDateTime and String trimming
- ⚡ Event Publishing - Built-in support for Spring ApplicationEventPublisher
- 🛡️ Exception Handling - Flexible error handling with supplier-based exceptions
- 🚀 Auto-Configuration - Automatic ObjectMapperService bean registration
dependencies {
implementation 'com.javaquery:spring:1.0.4'
}<dependency>
<groupId>com.javaquery</groupId>
<artifactId>spring</artifactId>
<version>1.0.4</version>
</dependency>The AbstractService provides common CRUD operations out of the box, reducing boilerplate code in your service layer.
importcom.javaquery.spring.service.AbstractService;
importorg.springframework.stereotype.Service;
@ServicepublicclassCustomerServiceImplextendsAbstractService<Customer, Long> implementsCustomerService {
publicCustomerServiceImpl(CustomerRepositoryrepository, ApplicationEventPublisherapplicationEventPublisher) {
super(repository, applicationEventPublisher);
}
// All CRUD operations are inherited, add custom methods as needed
}// Save single entityCustomercustomer = customerService.save(customer);
// Save multiple entitiesList<Customer> customers = customerService.saveAll(customerList);
// Find by IDCustomercustomer = customerService.findById(1L, null);
// Find by ID with exception handlingCustomercustomer = customerService.findById(1L, () -> newNotFoundException("Customer not found"));
// Delete by IDCustomerdeleted = customerService.deleteById(1L, null);
// Delete entitycustomerService.delete(customer);
// Check existencebooleanexists = customerService.existsById(1L, null);
// Find all by IDsList<Customer> customers = customerService.findAllById(List.of(1L, 2L, 3L));
// Find all with paginationPageData<Customer> page = customerService.findAll(Pageable.of(0, 10));
// Count recordslongcount = customerService.count();The AbstractSpecification interface provides convenient methods for building JPA Specifications.
importcom.javaquery.spring.repository.AbstractSpecification;
importorg.springframework.data.jpa.repository.JpaRepository;
importorg.springframework.data.jpa.repository.JpaSpecificationExecutor;
publicinterfaceCustomerRepositoryextendsJpaRepository<Customer, Long>,
JpaSpecificationExecutor<Customer>,
AbstractSpecification<Customer> {
}importorg.springframework.data.jpa.domain.Specification;
// Equal comparisonSpecification<Customer> spec = customerRepository.equal("status", "ACTIVE");
// Not equalspec = customerRepository.notEqual("status", "DELETED");
// In collectionspec = customerRepository.in("id", List.of(1L, 2L, 3L));
// Not in collectionspec = customerRepository.notIn("status", List.of("DELETED", "SUSPENDED"));
// Like patternspec = customerRepository.like("email", "%@example.com");
// Starts withspec = customerRepository.startsWith("firstName", "John");
// Ends withspec = customerRepository.endsWith("email", "@gmail.com");
// Containsspec = customerRepository.contains("name", "smith");// Combine multiple specificationsSpecification<Customer> spec = Specification
.where(customerRepository.equal("status", "ACTIVE"))
.and(customerRepository.contains("email", "@gmail.com"))
.and(customerRepository.startsWith("firstName", "J"));
// Use with servicePageData<Customer> results = customerService.findAll(spec, Pageable.of(0, 20));
List<Customer> allResults = customerService.findAll(spec);A simple wrapper for paginated results that includes metadata about the page.
importcom.javaquery.spring.data.PageData;
PageData<Customer> page = customerService.findAll(Pageable.of(0, 20));
longtotalElements = page.getTotalElements(); // Total recordsinttotalPages = page.getTotalPages(); // Total pagesintcurrentPage = page.getCurrentPage(); // Current page numberintpageSize = page.getPageSize(); // Page sizeList<Customer> data = page.getData(); // Actual dataThe module includes custom Jackson deserializers that are automatically registered with Spring Boot.
Flexibly deserializes dates and datetimes from multiple formats:
- ISO format with 'T':
2025-07-25T10:30:45 - Space-separated:
2025-07-25 10:30:45 - Date only:
2025-07-25(converted to start of day)
publicclassEvent {
privateLocalDateTimestartDate; // Automatically uses custom deserializerprivateLocalDateTimeendDate;
}
// JSON input - all formats supported:// {"startDate": "2025-07-25T10:30:45", "endDate": "2025-07-25"}Automatically trims leading and trailing whitespace from all string values during deserialization.
publicclassCustomer {
privateStringname; // Automatically trimmedprivateStringemail;
}
// JSON input: {"name": " John Doe ", "email": " john@example.com "}// Result: name = "John Doe", email = "john@example.com"Both deserializers are enabled by default but can be controlled via application properties:
# Disable LocalDateTimeJsonDeserializer (default: true)javaquery.jackson.deserializer.localdatetime.enabled=false
# Disable StringJsonDeserializer (default: true)javaquery.jackson.deserializer.string-trim.enabled=falseOr in YAML:
javaquery:
jackson:
deserializer:
localdatetime:
enabled: false # Disable LocalDateTime custom deserializerstring-trim:
enabled: false # Disable String trimming deserializer@ServicepublicclassCustomerServiceImplextendsAbstractService<Customer, Long> implementsCustomerService {
publicCustomerServiceImpl(CustomerRepositoryrepository, ApplicationEventPublisherapplicationEventPublisher) {
super(repository, applicationEventPublisher);
}
// Add custom business logicpublicList<Customer> findActiveCustomers() {
Specification<Customer> spec = ((CustomerRepository) repository).equal("status", "ACTIVE");
returnfindAll(spec);
}
publicCustomeractivateCustomer(Longid) {
Customercustomer = findById(id, () -> newNotFoundException("Customer not found"));
customer.setStatus("ACTIVE");
// Use the event publisher for domain eventsapplicationEventPublisher.publishEvent(
newCustomerActivatedEvent(customer));
returnsave(customer);
}
}// Pattern 1: Return null if not foundCustomercustomer = customerService.findById(id, null);
if (customer == null) {
// Handle not found case
}
// Pattern 2: Throw custom exception if not foundCustomercustomer = customerService.findById(id, () -> newCustomerNotFoundException("Customer with id " + id + " not found"));
// Pattern 3: Check existence and throw if not existsbooleanexists = customerService.existsById(id, () -> newCustomerNotFoundException("Customer with id " + id + " not found"));publicinterfaceCustomerRepositoryextendsJpaRepository<Customer, Long>,
JpaSpecificationExecutor<Customer>,
AbstractSpecification<Customer> {
defaultSpecification<Customer> isActive() {
returnequal("status", "ACTIVE");
}
defaultSpecification<Customer> hasEmailDomain(Stringdomain) {
returnendsWith("email", "@" + domain);
}
defaultSpecification<Customer> createdAfter(LocalDateTimedate) {
return (root, query, cb) -> cb.greaterThan(root.get("createdAt"), date);
}
}
// UsageSpecification<Customer> spec = Specification
.where(customerRepository.isActive())
.and(customerRepository.hasEmailDomain("gmail.com"))
.and(customerRepository.createdAfter(LocalDateTime.now().minusDays(30)));
List<Customer> recentGmailCustomers = customerService.findAll(spec);Base class for service implementations providing CRUD operations.
Methods:
T save(T entity)- Saves an entity<S extends T> List<S> saveAll(Iterable<S> entities)- Saves multiple entitiesT findById(ID id, Supplier<? extends RuntimeException> throwExceptionIfNotFound)- Finds entity by IDT deleteById(ID id, Supplier<? extends RuntimeException> throwExceptionIfNotFound)- Deletes entity by IDvoid delete(T entity)- Deletes an entityboolean existsById(ID id, Supplier<? extends RuntimeException> throwExceptionIfNotFound)- Checks existenceList<T> findAllById(Iterable<ID> ids)- Finds multiple entities by IDsPageData<T> findAll(Specification<T> specification, Pageable pageable)- Finds with specification and paginationList<T> findAll(Specification<T> specification)- Finds with specificationPageData<T> findAll(Pageable pageable)- Finds with paginationlong count()- Counts total entities
Interface providing convenient specification builders.
Methods:
Specification<T> equal(String field, Object value)- Field equals valueSpecification<T> notEqual(String field, Object value)- Field not equals valueSpecification<T> in(String field, Iterable<?> values)- Field in collectionSpecification<T> notIn(String field, Iterable<?> values)- Field not in collectionSpecification<T> like(String field, String pattern)- Field matches patternSpecification<T> startsWith(String field, String prefix)- Field starts with prefixSpecification<T> endsWith(String field, String suffix)- Field ends with suffixSpecification<T> contains(String field, String infix)- Field contains substring
Immutable wrapper for paginated results.
Properties:
long totalElements- Total number of elementsint totalPages- Total number of pagesint currentPage- Current page number (0-based)int pageSize- Number of elements per pageList<T> data- The actual data for this page
| Module Version | Spring Boot | Java | Status |
|---|---|---|---|
| 1.0.4 | 3.0.x - 3.5.x | 17+ | ✅ Verified |
| 1.0.4 | 2.7.x | 11+ | ✅ Maintained |
| 1.0.3 | 3.0.x - 3.5.x | 17+ | ✅ Still Works |
| 1.0.3 | 2.7.x | 11+ | ✅ Still Works |
| 1.0.2 | 3.0.x - 3.5.x | 17+ | ✅ Still Works |
| 1.0.2 | 2.7.x | 11+ | ✅ Still Works |
| 1.0.1 | 2.7.x | 11+ | ✅ Still Works |
| 1.0.0 | 2.7.x | 11+ | ✅ Still Works |
- Java: 11+ (Spring Boot 2.7.x) or 17+ (Spring Boot 3.x)
- Spring Boot: 2.7.x or 3.0.x+
- Spring Data JPA: Required for AbstractService and repository features
- Jackson: Required for ObjectMapperService and JSON deserializers
- Lombok: Required for PageData
This project is part of the JLite library suite.
Contributions are welcome! Please ensure all tests pass before submitting pull requests.
javaquery
Current version: 1.0.4