I am simply trying to create a Spring boot Hibernate CRUD REST API through this code:
EmployeController.java
#RestController
#RequestMapping("/api")
public class EmployeController {
#Autowired
private EmployeService employeService;
#GetMapping("/employe")
public List<Employe> get(){
return employeService.get();
}
}
Employe.java
#Entity
#Table(name="employe")
public class Employe {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column
private int id;
#Column
private String name;
#Column
private String gender;
#Column
private String department;
#Column
private Date dob;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
public Date getDob() {
return dob;
}
public void setDob(Date dob) {
this.dob = dob;
}
#Override
public String toString() {
return "Employe [id=" + id + ", name=" + name + ", gender=" + gender + ", department=" + department + ", dob="
+ dob + "]";
}
}
EmployeService.java
public interface EmployeService {
List<Employe> get();
Employe get(int id);
void save(Employe employe);
void delete(int id);
}
EmployeServiceImplement.java
#Service
public class EmployeServiceImplement implements EmployeService {
#Autowired
private EmployeDAO employeDAO;
#Transactional
#Override
public List<Employe> get() {
return employeDAO.get();
}
}
EmployeDAO.java
public interface EmployeDAO {
List<Employe> get();
Employe get(int id);
void save(Employe employe);
void delete(int id);
}
EmployeDAOImplement.java
#Repository
public class EmployeDAOImplement implements EmployeDAO {
#Autowired
private EntityManager entityManager;
#Override
public List<Employe> get() {
Session currentSession = entityManager.unwrap(Session.class);
Query<Employe> query = currentSession.createQuery("from Employe", Employe.class);
List<Employe>list = query.getResultList();
return list;
}
}
I have write all the configuration related to MySQl database into the application.properties and when i run this project as Spring Boot App and go to the Postman and tried like this
and i a unable to understan why it always throws 404 error every time , can anyone tell me what i am missing in this code.
Try with this GET request, it may help you:
http://localhost:8080/api
I checked your code.
where is #RestController for your Controller file and where is #RequestMapping For your method in Controller class?
maybe you should write something like this according to your need.
tell me if you need more help.
#RestController
#RequestMapping("/api")
public class EmployeController {
#RequestMapping(value = "/employ")
public void employ() {
}
}
Instead of this -
#Override
public List get()
Use this -
#RequestMapping(value = "/Employe", method = RequestMethod.GET)
public List get()
Related
I developed Spring Boot CRUD application. The database I have connected is PostgreSQL. #GetMapping is working properly and an empty array of objects can be retrieved by the GET request. But in #PostMapping, the POST request gives a 404 error.
đź“ŚSpringRecapApplication.java
package com.example.SpringRecap;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration;
import org.springframework.web.bind.annotation.*;
import java.util.List;
#RestController
#SpringBootApplication(exclude = SecurityAutoConfiguration.class)
//#RequestMapping("api/v1/customers")
//#EnableWebMvc
#RequestMapping(name = "api/v1/customers" ,method = RequestMethod.POST)
public class SpringRecapApplication {
//dependency injection
private static CustomerRepository customerRepository;
public SpringRecapApplication(CustomerRepository customerRepository) {
this.customerRepository = customerRepository;
}
public static void main(String[] args) {
SpringApplication.run(SpringRecapApplication.class, args);
}
#GetMapping
public List<Customer> getCustomer() {
return customerRepository.findAll();
}
record NewCustomerRequest(
String name,
String email,
Integer age
) {
#PostMapping
public void addCustomer(#RequestBody NewCustomerRequest newCustomerRequest) {
Customer customer = new Customer();
customer.setAge(newCustomerRequest.age());
customer.setName(newCustomerRequest.name());
customer.setEmail(newCustomerRequest.email());
customerRepository.save(customer);
}
}
}
customerRepository.save(customer); doesn't allow to make the dependency injection final. ( private static CustomerRepository customerRepository;). IDEA suggests making it static. But it didn't work. When I was using #RequestMapping("api/v1/customers"), a 405 error was received. Then I fixed that issue by doing as below,
#RequestMapping(name = "api/v1/customers" ,method = RequestMethod.POST)
đź“ŚCustomerRepository.java
package com.example.SpringRecap;
import org.springframework.data.jpa.repository.JpaRepository;
public interface CustomerRepository extends JpaRepository<Customer,Integer> {
}
đź“ŚCustomer.java
package com.example.SpringRecap;
import jakarta.persistence.*;
import java.util.Objects;
#Entity
public class Customer {
#Id
#SequenceGenerator(
name = "customer_id_sequence",
sequenceName = "customer_id_sequence",
allocationSize = 1
)
#GeneratedValue(
strategy = GenerationType.SEQUENCE,
generator = "customer_id_sequence"
)
private Integer id;
private String name;
private String email;
private Integer age;
public Customer(Integer id, String name, String email, Integer age) {
this.id = id;
this.name = name;
this.email = email;
this.age = age;
}
public Customer() {
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
#Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Customer customer = (Customer) o;
return Objects.equals(id, customer.id) && Objects.equals(name, customer.name) && Objects.equals(email, customer.email) && Objects.equals(age, customer.age);
}
#Override
public int hashCode() {
return Objects.hash(id, name, email, age);
}
#Override
public String toString() {
return "Customer{" +
"id=" + id +
", name='" + name + '\'' +
", email='" + email + '\'' +
", age=" + age +
'}';
}
}
Postman:
Please put a comment if further information is needed to get the solution.
The problem with your code is that you specified the POST endpoint as part of your DTO and not as part of your controller. As your DTO is not a Spring managed bean, Spring won't map the URL to your endpoint. Anyways, you should move your endpoints into a seperate class. Example:
#RestController
#RequestMapping("api/v1/customers")
public class CustomerController {
private final CustomerRepository customerRepository;
public SpringRecapApplication(CustomerRepository customerRepository) {
this.customerRepository = customerRepository;
}
#GetMapping
public List<Customer> getCustomer() {
return customerRepository.findAll();
}
#PostMapping
public void addCustomer(#RequestBody NewCustomerRequest newCustomerRequest) {
Customer customer = new Customer();
customer.setAge(newCustomerRequest.age());
customer.setName(newCustomerRequest.name());
customer.setEmail(newCustomerRequest.email());
customerRepository.save(customer);
}
// Helper classes
record NewCustomerRequest(String name, String email, Integer age) { }
}
It would be best if you moved your DTO in a seperate class as well. I recommend placing the DTOs in a dto package and your controllers in a controller package.
Two side notes: you shouldn't expose your entities via your API. You should use DTOs for incoming and outgoing data. Check out lombok and mapstruct, they make this pretty easy.
I am trying to create an application to save data into the Oracle database using CrudRepository. Here is my repositiry:
public interface CustomerRepository extends CrudRepository<Customer, Long> {
List<Customer> findByEmail(String email);
List<Customer> findByDate(Date date);
// custom query example and return a stream
#Query("select c from Customer c where c.email = :email")
Stream<Customer> findByEmailReturnStream(#Param("email") String email);
}
My application.property looks like:
spring.datasource.url=jdbc:oracle:thin:#vgdevst-scan.hhs.local:1521/EONDEV.hhslocal
spring.datasource.username=EON_USER
spring.datasource.password=EON_USERD
spring.datasource.driver-class-oracle.jdbc.driver.OracleDriver
While my customer entity class is :
#Entity
public class Customer {
//http://www.oracle.com/technetwork/middleware/ias/id-generation-083058.html
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "CUST_SEQ")
#SequenceGenerator(sequenceName = "customer_seq", initialValue = 1, allocationSize = 1, name = "CUST_SEQ")
Long id;
String name;
String email;
//#Temporal(TemporalType.DATE)
#Column(name = "CREATED_DATE")
Date date;
public Customer(String name, String email, Date date) {
this.name = name;
this.email = email;
this.date = date;
}
public Customer(Long id, String name, String email, Date date) {
super();
this.id = id;
this.name = name;
this.email = email;
this.date = date;
}
public Customer() {
}
#Override
public String toString() {
return "Customer{" +
"id=" + id +
", name='" + name + '\'' +
", email='" + email + '\'' +
", date=" + date +
'}';
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
I am trying to save a new cutomer to database using:
#SpringBootApplication
public class Application implements CommandLineRunner {
private static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
#Autowired
DataSource dataSource;
#Autowired
CustomerRepository customerRepository;
public static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
}
#Transactional(readOnly = true)
#Override
public void run(String... args) throws Exception {
System.out.println("DATASOURCE = " + dataSource);
customerRepository.save(new Customer(new Long(4),"Amit","a.r#state.ma.us",new Date()));
System.out.println("\n1.findAll()...");
for (Customer customer : customerRepository.findAll()) {
System.out.println(customer);
}
}
}
I do not see the new customer added either in sops or in database. What am i missing here?
Your problem seems to be that you are executing the save statement in a readOnly transaction. The solution could be as simple as removing that property.
Reading the readOnly flag documentation, it states that:
A boolean flag that can be set to true if the transaction is effectively read-only, allowing for corresponding optimizations at runtime.
Use only #Transactional:
#Transactional
#Override
public void run(String... args) throws Exception {
// the rest of your code ...
}
The code was working just fine.
Its just that in my application code, i had changed the application.property file as per my old code and instead of "spring.datasource.url" i had put "appname.datasource.url", which is why code never interacted with DB.
Problem: it works till i try to add Student obejcts to Database, but the tables are being created correctly .
I can't simplify the post any further. But it's mainly code that doesn't require a lot of reading, it's a simple spring data repository service model. I posted it all due to the fact idk what am i doing wrong. Problem is in the JPA mapping.
I got the example from over here http://www.java2s.com/Tutorial/Java/0355__JPA/OneToManyBidirectional.htm
MDOELS
#Entity
public class Department {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
private String name;
#OneToMany(mappedBy="department")
private Collection<Student> students;
public Department() {
}
public Department(String name) {
this.name = name;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String deptName) {
this.name = deptName;
}
public Collection<Student> getStudents() {
return students;
}
public void setStudent(Collection<Student> students) {
this.students = students;
}
public String toString() {
return "Department id: " + getId() +
", name: " + getName();
}
}
#Entity
public class Student {
#Id #GeneratedValue(strategy=GenerationType.IDENTITY)
private int id;
private String name;
#ManyToOne (cascade=CascadeType.ALL)
private Department department;
public Student() {
}
public Student(String name, Department department) {
this.name = name;
this.department = department;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Department getDepartment() {
return department;
}
public void setDepartment(Department department) {
this.department = department;
}
public String toString() {
return "\n\nID:" + id + "\nName:" + name + "\n\n" + department;
}
}
REPOSITORIES
#Repository
public interface DepartmentRepository extends JpaRepository<Department, Integer> {
Department findByName(String name);
}
#Repository
public interface StudentRepository extends JpaRepository<Student, Integer> {
Student findByName(String name);
}
SERVICES
#Service
public class StudentService {
private final StudentRepository studentRepository;
#Autowired
public StudentService(StudentRepository studentRepository) {
this.studentRepository = studentRepository;
}
public void addToDatabase(Student student) {
this.studentRepository.saveAndFlush(student);
}
public Student getStudentByName(String name) {
return studentRepository.findByName(name);
}
}
#Service
public class DepartmentService {
private final DepartmentRepository departmentRepository;
#Autowired
public DepartmentService(DepartmentRepository departmentRepository) {
this.departmentRepository = departmentRepository;
}
public void addToDataBase(List<Department> department) {
this.departmentRepository.save(department);
department.forEach(this.departmentRepository::saveAndFlush);
}
public Department getDepartmentByName(String name){
return this.departmentRepository.findByName(name);
}
}
My main method
#Component
public class Terminal implements CommandLineRunner {
private final StudentService studentService;
private final DepartmentService departmentService;
#Autowired
public Terminal(StudentService studentService, DepartmentService departmentService) {
this.studentService = studentService;
this.departmentService = departmentService;
}
#Override
public void run(String... strings) throws Exception {
Department department = new Department("dep1");
Department department1 = new Department("dep2");
Department department2 = new Department("dep3");
Department department3 = new Department("dep4");
List<Department> departments = new ArrayList<>(Arrays.asList(department, department1, department2, department3));
this.departmentService.addToDataBase(departments);
//
Student student = new Student("pesho", department);
Student student11 = new Student("gosho", department1);
this.studentService.addToDatabase(student11);
this.studentService.addToDatabase(student);
student = new Student("sasho", department2);
this.studentService.addToDatabase(student);
// System.out.println(this.studentService.getStudentByName("gosho").getDepartment1());
// System.out.println("CHECKING ONE TO ONE BIDIRECTIONAL: " + this.departmentService.getDepartmentByName("dep1").getStudent());
}
}
So here when i try to add students in the students table it gives an error
The error is the fallowing
Caused by: org.hibernate.PersistentObjectException: detached entity passed to persist: app.models.Department
you added cascade= CascadeType.ALL for Department in Student class and save departments separete. this.departmentService.addToDataBase(departments);
fix : dont call
departmentService.addToDataBase(departments);
or remove CascadeType.ALL from Student
Well I can't understand you problem completely but here's what I would like to add. Cascading for add operation is not implemented or it's incomplete. Hope it helps.
This is my Controller method, i am trying to read my database by providing zip, cityname and province name.
#RequestMapping(value = "/retrieve", method = RequestMethod.GET)
public #ResponseBody String retrieveObjectThroughAjax(ModelMap model){
//Calling Service Method to read data according to zip,cityName and province provide
PropertyItems propertyItems=getPropertyTypeandAddressService.readAddressFromZip("H2H-
2N3","Montreal","Quebec");
Gson gson = new Gson();
String json = null;
try{
json = gson.toJson(propertyItems); // serializing object
}catch(Exception e){
logger.error(Constants.METHOD_INSIDE_MESSAGE +"getAuthors",e);
}
logger.debug(json);
return json;
}
}
Service Method
#Service
public class GetPropertyTypeandAddressServiceImpl implements GetPropertyTypeandAddressService{
#Autowired
private GetPropertyTypeandAddressDAO getPropertyTypeandAddressDAO;
#Transactional
public PropertyItems readAddressFromZip(String zipCode,String cityName,String provinceName){
PropertyItems propertyItems=getPropertyTypeandAddressDAO.getAddressFromZip(zipCode, cityName, provinceName);
Hibernate.initialize(propertyItems);
return propertyItems;
}
}
DAO Method
#Repository
public class GetPropertyTypeandAddressDAOimp implements GetPropertyTypeandAddressDAO{
#Autowired
private SessionFactory sessionFactory;
#Override
public PropertyItems getAddressFromZip(String zipCode,String cityName,String provinceName) {
PropertyItems propertyitems = new PropertyItems();
Criteria criteria = sessionFactory.getCurrentSession().createCriteria(PropertyItems.class,"propertyItemsClass");
if(zipCode != null){
criteria.createAlias("propertyItemsClass.address","address");
criteria.add(Restrictions.eq("address.zip",zipCode));
List<PropertyItems> propertyitem = criteria.list();
if(propertyitem.size()>0){
propertyitems = propertyitem.get(0);
}
}
else if(cityName != null){
criteria.createAlias("propertyItemsClass.address","address");
criteria.add(Restrictions.eq("address.city","city"));
criteria.add(Restrictions.eq("city.cityname",cityName));
List<PropertyItems> propertyitem = criteria.list();
if(propertyitem.size()>0){
propertyitems = propertyitem.get(0);
}
}
else if(provinceName != null){
criteria.createAlias("propertyItemsClass.address","address");
criteria.add(Restrictions.eq("address.city","city"));
criteria.add(Restrictions.eq("city.provinces","provinces"));
criteria.add(Restrictions.eq("provinces.provinceName",provinceName));
List<PropertyItems> propertyitem = criteria.list();
if(propertyitem.size()>0){
propertyitems = propertyitem.get(0);
}
}
return propertyitems;
}
}
Console Error
09:53:56,988 ERROR HelloController:567 - Inside Method: getAuthors org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.agilemaple.common.entity.Property.propertyType, no session or session was closed
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383)
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375)
As requested my Property Items Look like this
Entity:
Propert Items
#Entity
#Table(name="web_property_item")
public class PropertyItems {
#Id
#GeneratedValue
private Integer id;
private String name;
#ManyToOne
#JoinColumn(name="property_type_id")
private PropertyType propertyType;
#OneToOne(mappedBy="propertyItems",cascade=CascadeType.ALL)
private Address address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public PropertyType getPropertyType() {
return propertyType;
}
public void setPropertyType(PropertyType propertyType) {
this.propertyType = propertyType;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
Entity : Property Type
#Entity
#Table(name="web_property_type")
public class PropertyType {
#Id
#GeneratedValue
private Integer id;
private String name;
#ManyToOne
#JoinColumn(name="property_id")
private Property property;
#OneToMany(fetch = FetchType.LAZY,mappedBy="propertyType", cascade=CascadeType.ALL)
private Set<PropertyItems> propertyItems;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Property getProperty() {
return property;
}
public void setProperty(Property property) {
this.property = property;
}
public Set<PropertyItems> getPropertyItems() {
return propertyItems;
}
public void setPropertyItems(Set<PropertyItems> propertyItems) {
this.propertyItems = propertyItems;
}
}
The problem in hibernate. Your field Set of properties has Lazy fetch method, it means that it will try to get when you call method get of this set. When u calling tojson methods, gson calls all get methods of object but in this moment hibernate session is close and hibernate can't open it in controller. I've faced with the same problem but directly on JSP. In a three weeks i resolved it by one more property for hibernate ( in your case) and I write code to opening session in view interceptor. I'm underground just right now, so I can't show property, but in a hour I will edit this answer and add property.
Added:
I remembered ! property is: hibernate.enable_lazy_load_no_trans = true
If it won't help, I will add code of opensessioninviewinterceptor.
#Override
public void addInterceptors(InterceptorRegistry registry) {
OpenSessionInViewInterceptor sessionInViewInterceptor = new OpenSessionInViewInterceptor();
sessionInViewInterceptor.setSessionFactory(sessionFactory());
}
When I run my Integrationtesting with Arquillan I get the following Error meesage javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist. Which probably is something with my ID and database.
Following is the class it is complaining about its a domain class :
#Entity
public class Customer implements IdHolder {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
private String firstName;
private String lastName;
private String email;
private String company;
public Customer() {
}
public Customer(long id, String firstName, String lastName, String email,
String company) {
setId(id);
setFirstName(firstName);
setLastName(lastName);
setEmail(email);
setCompany(company);
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
}
I have also have a testfixture to make test easier and its implemented like this :
public class TestFixture {
private static Logger log = Logger.getLogger(TestFixture.class.getName());
public static Customer getCustomer(long id, String firstName,
String lastName, String email, String company) {
Customer customer = new Customer();
customer.setId(id);
customer.setFirstName(firstName);
customer.setLastName(lastName);
customer.setEmail(email);
customer.setCompany(company);
return customer;
}
public static Customer getCustomer() {
return getCustomer(1, "Darth", "Vader", "skywalker#gmail.com", "Starwars");
}
public static Customer getCustomer(String name, String lastName, String email, String company) {
return getCustomer(0, name, lastName, email, company);
}
public static Archive<?> createIntegrationTestArchive() {
MavenDependencyResolver mvnResolver = DependencyResolvers.use(
MavenDependencyResolver.class).loadMetadataFromPom("pom.xml");
WebArchive war = ShrinkWrap.create(WebArchive.class, "agent_test.war")
.addPackages(true, "se.lowdin")
.addPackages(true, "se.plushogskolan")
.addAsWebInfResource("beans.xml")
.addAsResource("META-INF/persistence.xml");
war.addAsLibraries(mvnResolver.artifact("org.easymock:easymock:3.2")
.resolveAsFiles());
war.addAsLibraries(mvnResolver.artifact("joda-time:joda-time:2.2")
.resolveAsFiles());
war.addAsLibraries(mvnResolver.artifact(
"org.jadira.usertype:usertype.core:3.1.0.CR8").resolveAsFiles());
log.info("JAR: " + war.toString(true));
return war;
}
}
And finally I have the integration test that I am using arquillan with. When I run the test the error above is coming up : javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist
#RunWith(Arquillian.class)
#Transactional(TransactionMode.ROLLBACK)
public class JpaCustomerIntegrationTest extends AbstractRepositoryTest<Customer, JpaCustomerRepository> {
#Inject JpaCustomerRepository repo;
#Test
public void testGetAllCustomers() {
Customer customer1 = TestFixture.getCustomer();
Customer customer2 = TestFixture.getCustomer();
customer1.setId(0);
customer2.setId(0);
repo.persist(customer1);
repo.persist(customer2);
List<Customer> getAllCustomersList = repo.getAllCustomers();
assertEquals("Check the amount from the list", 2, getAllCustomersList.size());
}
#Override
protected JpaCustomerRepository getRepository() {
return (JpaCustomerRepository) repo;
}
#Override
protected Customer getEntity1() {
return TestFixture.getCustomer();
}
#Override
protected Customer getEntity2() {
return TestFixture.getCustomer();
}
}
and
public abstract class JpaRepository<E extends IdHolder> implements BaseRepository<E> {
/**
* The JPA type this repository can handle. Only known at runtime. This
* value is set in the constructor.
*/
protected Class<E> entityClass;
#PersistenceContext
protected EntityManager em;
#SuppressWarnings("unchecked")
public JpaRepository() {
/*
* A little magic to look into the superclass to find the type we are
* working on. We use that type in findById() for example .
*/
ParameterizedType genericSuperclass = (ParameterizedType) getClass().getGenericSuperclass();
this.entityClass = (Class<E>) genericSuperclass.getActualTypeArguments()[0];
}
#Override
public long persist(E entity) {
em.persist(entity);
return entity.getId();
}
#Override
public void remove(E entity) {
em.remove(entity);
}
#Override
public E findById(long id) {
return em.find(entityClass, id);
}
#Override
public void update(E entity) {
em.merge(entity);
}
}
I really feel like an idiot when I am not able to solve this can anyone help me and explain what is wrong?
You could change Customer.id from long to Long. Before persisting the entity just set Id to null. This should help.