Issue on adding a custom functionality to a Spring Data Repository

Question

I'm getting data through inbuilt methods of CrudRepository, but getting error while applying customized method to data repository.

This is the repository

@Repository
public interface EmployeeRepository extends CrudRepository<Employee, Integer> {
    List<Employee> findAllByEmployeeLastName(String last);
}

This is the Service Class

@Service
public class EmployeeService {

    private EmployeeRepository employeeRepository;

    @Autowired
    public EmployeeService(EmployeeRepository _employeeRepository) {
        employeeRepository = _employeeRepository;
    }

    public Iterable<Employee> findAll() {
        return employeeRepository.findAll();
    }

    public Employee findById(int id) {

        Optional<Employee> id_of_employee = employeeRepository.findById(id);

        Employee employee = null;

        if (id_of_employee.isPresent()) {
            employee = id_of_employee.get();
        } else {
            throw new RuntimeException("ID not found : " + id);
        }

        return employee;
    }

    public List<Employee> getEmployeeByLastName(String last) {
        return employeeRepository.findAllByEmployeeLastName(last);
    }
}

This is the Controller

@RestController
@RequestMapping("/api") public class EmployeeRestController {

    public EmployeeService employeeService;

    @Autowired
    public EmployeeRestController(EmployeeService _employeeService) {
        employeeService = _employeeService;
    }

    @GetMapping("/list_of_employees")
    public Iterable<Employee> getAllEmployees() {
        return employeeService.findAll();
    }

    @GetMapping("/find_an_employee_by_id/{id}")
    public Employee getAnEmplopyeeByID(@PathVariable int id) {
        Employee employee = employeeService.findById(id);

        if (employee == null) {
            throw new RuntimeException("ID not found : " + id);
        }

        return employee;

    }

    @RequestMapping("/find_employee_by_last_name/{last}")
    public List<Employee> getEmployeeByLastName(@PathVariable(value = "last") String last) {
        return employeeService.getEmployeeByLastName(last);
    }

}

getEmployeeByLastName() method is the customized method here, it's giving error, do I have to add some xml file to run a custom method? Or am I going wrong somewhere else? Would really appreciate any assist on this.

This is the entity class

@Entity
@Table(name = "employees")
public class Employee {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;

    @Column(name = "first_name")
    private String first_name;

    @Column(name = "last")
    private String last;

    @Column(name = "salary")
    private double salary;

    @Column(name = "email")
    private String email;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirst_name() {
        return first_name;
    }

    public void setFirst_name(String first_name) {
        this.first_name = first_name;
    }

    public String getLast() {
        return last;
    }

    public void setLast(String last) {
        this.last= last;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Employee() {
    }
}

Stack Trace:

[I:\spring_boot_project_factory\project_factory_1\section_1\Project\target\classes\com\project\service\EmployeeService.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepository': Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List com.project.repository.EmployeeRepository.findByEmployeeLastName(java.lang.String)! No property employeeLastName found for type Employee! 2019-04-19 15:02:25.321 INFO 3920 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default' 2019-04-19 15:02:25.334 INFO 3920 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated... 2019-04-19 15:02:25.345 INFO 3920 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed. 2019-04-19 15:02:25.348 INFO 3920 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2019-04-19 15:02:25.390 INFO 3920 --- [ restartedMain] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2019-04-19 15:02:25.409 ERROR 3920 --- [ restartedMain] o.s.boot.SpringApplication
: Application run failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'employeeRestController' defined in file

Answer 1

While creating custom method in data repository your method naming convention is mandatory, is depend on your DAO class fields.

In your DAO class for the last name, you have created the last variable so your method name can't be findAllByLastName(String last) because you don't have any variable called lastName in your DAO class.

So should be findAllByLast(String last); or findByLast(String last);

Answer 2

In the logs, it is stated that

Failed to create query for method public abstract java.util.List com.project.repository.EmployeeRepository.findByEmployeeLastName(java.lang.String)! No property employeeLastName found for type Employee

your method name in EmployeeRepository should be findAllByLast(String last);

Also i would recommend to please read about java coding and naming conventions so you can avoid such mistakes.