Hibernate with Spring Boot
From My Limbic Wiki
Hibernate ORM handles object-relational impedance mismatch problems by replacing direct, persistent database accesses with high-level object handling functions.
Vulgarization
Dependencies
pom.xml file
org.springframework.boot.spring-boot-starter-web org.springframework.boot.spring-boot-starter-data-jpa com.h2database.h2
Entity
@Entity @Table(name="TABLE_EMPLOYEE") public class EmployeeEntity{ @Id @GeneratedValue private Long id; @Column(name="column_name", nullable=false, length=200) @Override public String toString() { ... } }
Repository
See the differences of : JpaRepository = PagingAndSortingRepository + CrudRepository here ==>> thumb|100px|JpaRepository
@Repository public interface EmployeeRepository extends JpaRepository<EmployeeEntity, Long> { ... }
Datasource Configuration
application.properties #Required spring.datasource.url=jdbc:h2:file:~/test spring.datasource.driverClassName=org.h2.Driver spring.datasource.username=user spring.datasource.password=password
#Optionnal # Enabling H2 Console spring.h2.console.enabled=true # Custom H2 Console URL spring.h2.console.path=/h2-console # create database schema from SQL files spring.jpa.hibernate.ddl-auto=none #Turn Statistics on and log SQL stmts spring.jpa.show-sql=true spring.jpa.properties.hibernate.format_sql=true spring.jpa.properties.hibernate.generate_statistics=false #logging.level.org.hibernate.type=trace #logging.level.org.hibernate.stat=debug logging.pattern.console=%d{yyyy-MM-dd HH:mm:ss} - %msg%n
Service
@Service public class EmployeeService { @Autowired TableNameRepository repository; ############### Get All public List<EmployeeEntity> getAllEmployees(){ List<EmployeeEntity> employeeList = repository.findAll(); if(employeeList.size() > 0) { return employeeList; } else { return new ArrayList<EmployeeEntity>(); } } ############### Get public EmployeeEntity getEmployeeById(Long id) throws RecordNotFoundException{ Optional<EmployeeEntity> employee = repository.findById(id); if(employee.isPresent()) { return employee.get(); } else { throw new RecordNotFoundException("No employee record exist for given id"); } } ############### Create or Update public EmployeeEntity createOrUpdateEmployee(EmployeeEntity entity) throws RecordNotFoundException{ Optional<EmployeeEntity> employee = 'repository.findById(entity.getId()); if(employee.isPresent()){ EmployeeEntity newEntity = employee.get(); newEntity.setEmail(entity.getEmail()); newEntity.setFirstName(entity.getFirstName()); newEntity.setLastName(entity.getLastName()); newEntity = repository.save(newEntity); return newEntity; } else { entity = repository.save(entity); return entity; } } ############### Delete public void deleteEmployeeById(Long id) throws RecordNotFoundException{ Optional<EmployeeEntity> employee = repository.findById(id); if(employee.isPresent()){ repository.deleteById(id); } else { throw new RecordNotFoundException("No employee record exist for given id"); } } }
Controller (REST)
@RestController @RequestMapping("/employees") public class EmployeeController{ @Autowired EmployeeService service; @GetMapping public ResponseEntity<List<EmployeeEntity>> getAllEmployees(){ List<EmployeeEntity> list = service.getAllEmployees(); return new ResponseEntity<List<EmployeeEntity>>(list, new HttpHeaders(), HttpStatus.OK); } @GetMapping("/{id}") public ResponseEntity<EmployeeEntity> getEmployeeById(@PathVariable("id") Long id) throws RecordNotFoundException { EmployeeEntity entity = service.getEmployeeById(id); return new ResponseEntity<EmployeeEntity>(entity, new HttpHeaders(), HttpStatus.OK); } @PostMapping public ResponseEntity<EmployeeEntity> createOrUpdateEmployee(EmployeeEntity employee) throws RecordNotFoundException { EmployeeEntity updated = service.createOrUpdateEmployee(employee); return new ResponseEntity<EmployeeEntity>(updated, new HttpHeaders(), HttpStatus.OK); } @DeleteMapping("/{id}") public HttpStatus deleteEmployeeById(@PathVariable("id") Long id) throws RecordNotFoundException { service.deleteEmployeeById(id); return HttpStatus.FORBIDDEN; } }
Exceptions
@ResponseStatus(value = HttpStatus.NOT_FOUND) public class RecordNotFoundException extends Exception { private static final long serialVersionUID = 1L; public RecordNotFoundException(String message) { super(message); } public RecordNotFoundException(String message, Throwable t) { super(message, t); } }