jpa控制器和级联删除出现问题
我有两个表，其中一个表与另一个表之间有一个简单的外键约束。 表Ajpa控制器和级联删除出现问题,jpa,foreign-keys,cascading-deletes,Jpa,Foreign Keys,Cascading Deletes,我有两个表，其中一个表与另一个表之间有一个简单的外键约束。 表A id:Long（主键） 表B id:Long（主键） a_id:Long（fk到表a:id） 如果我从表A中删除，我希望它从表B中级联删除，因此表A中的外键在JPA实体中建模如下 @OneToMany(cascade = CascadeType.ALL, mappedBy = "a_id", orphanRemoval = true) @CascadeOnDelete private List<B> bList; 但
id:Long（主键） 表B
id:Long（主键）
a_id:Long（fk到表a:id） 如果我从表A中删除，我希望它从表B中级联删除，因此表A中的外键在JPA实体中建模如下
@OneToMany(cascade = CascadeType.ALL, mappedBy = "a_id", orphanRemoval = true)
@CascadeOnDelete
private List<B> bList;
List<String> illegalOrphanMessages = null;
List<B> bListOrphanCheck = a.getBList();
for (B bListOrphanCheckB : bListOrphanCheck) {
if (illegalOrphanMessages == null) {
illegalOrphanMessages = new ArrayList<String>();
}
illegalOrphanMessages.add("This A (" + a + ") cannot be destroyed since the B " + bListOrphanCheckB + " in its bList field has a non-nullable a_id field.");
}
列表非法消息=null；
List bListOrphanCheck=a.getBList（）；
对于（B bListOrphanCheck B:bListOrphanCheck）{
if（illegalOrphanMessages==null）{
illegalOrphanMessages=新ArrayList（）；
}
添加（“此A（“+A+”）无法销毁，因为其bList字段中的B“+bListOrphanCheckB+”具有不可为空的A_id字段。”）；
}
package test.controllers;
import java.io.Serializable;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import uk.co.utel.dataaccess.entities.B;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import uk.co.utel.dataaccess.controllers.exceptions.IllegalOrphanException;
import uk.co.utel.dataaccess.controllers.exceptions.NonexistentEntityException;
import uk.co.utel.dataaccess.entities.A;
public class AJpaController implements Serializable {
public AJpaController(EntityManagerFactory emf) {
this.emf = emf;
}
private EntityManagerFactory emf = null;
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
public void create(A a) {
if (a.getBList() == null) {
a.setBList(new ArrayList<B>());
}
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
List<B> attachedBList = new ArrayList<B>();
for (B bListBToAttach : a.getBList()) {
bListBToAttach = em.getReference(bListBToAttach.getClass(), bListBToAttach.getId());
attachedBList.add(bListBToAttach);
}
a.setBList(attachedBList);
for (B bListB : a.getBList()) {
A oldAIdOfBListB = bListB.getAId();
bListB.setAId(a);
bListB = em.merge(bListB);
if (oldAIdOfBListB != null) {
oldAIdOfBListB.getBList().remove(bListB);
oldAIdOfBListB = em.merge(oldAIdOfBListB);
}
}
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public void edit(A a) throws IllegalOrphanException, NonexistentEntityException, Exception {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
A persistentA = em.find(A.class, a.getId());
List<B> bListOld = persistentA.getBList();
List<B> bListNew = a.getBList();
List<String> illegalOrphanMessages = null;
for (B bListOldB : bListOld) {
if (!bListNew.contains(bListOldB)) {
if (illegalOrphanMessages == null) {
illegalOrphanMessages = new ArrayList<String>();
}
illegalOrphanMessages.add("You must retain B " + bListOldB + " since its aId field is not nullable.");
}
}
if (illegalOrphanMessages != null) {
throw new IllegalOrphanException(illegalOrphanMessages);
}
List<B> attachedBListNew = new ArrayList<B>();
for (B bListNewBToAttach : bListNew) {
bListNewBToAttach = em.getReference(bListNewBToAttach.getClass(), bListNewBToAttach.getId());
attachedBListNew.add(bListNewBToAttach);
}
bListNew = attachedBListNew;
a.setBList(bListNew);
for (B bListNewB : bListNew) {
if (!bListOld.contains(bListNewB)) {
A oldAIdOfBListNewB = bListNewB.getAId();
bListNewB.setAId(a);
bListNewB = em.merge(bListNewB);
if (oldAIdOfBListNewB != null && !oldAIdOfBListNewB.equals(a)) {
oldAIdOfBListNewB.getBList().remove(bListNewB);
oldAIdOfBListNewB = em.merge(oldAIdOfBListNewB);
}
}
}
em.getTransaction().commit();
} catch (Exception ex) {
String msg = ex.getLocalizedMessage();
if (msg == null || msg.length() == 0) {
Long id = a.getId();
if (findA(id) == null) {
throw new NonexistentEntityException("The a with id " + id + " no longer exists.");
}
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
public void destroy(Long id) throws IllegalOrphanException, NonexistentEntityException {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
A a;
try {
a = em.getReference(A.class, id);
a.getId();
} catch (EntityNotFoundException enfe) {
throw new NonexistentEntityException("The a with id " + id + " no longer exists.", enfe);
}
List<String> illegalOrphanMessages = null;
List<B> bListOrphanCheck = a.getBList();
for (B bListOrphanCheckB : bListOrphanCheck) {
if (illegalOrphanMessages == null) {
illegalOrphanMessages = new ArrayList<String>();
}
illegalOrphanMessages.add("This A (" + a + ") cannot be destroyed since the B " + bListOrphanCheckB + " in its bList field has a non-nullable aId field.");
}
em.remove(a);
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public List<A> findAEntities() {
return findAEntities(true, -1, -1);
}
public List<A> findAEntities(int maxResults, int firstResult) {
return findAEntities(false, maxResults, firstResult);
}
private List<A> findAEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(A.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
public A findA(Long id) {
EntityManager em = getEntityManager();
try {
return em.find(A.class, id);
} finally {
em.close();
}
}
public int getACount() {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
Root<A> rt = cq.from(A.class);
cq.select(em.getCriteriaBuilder().count(rt));
Query q = em.createQuery(cq);
return ((Long) q.getSingleResult()).intValue();
} finally {
em.close();
}
}
}
package test.controller；
导入java.io.Serializable；
导入javax.persistence.Query；
导入javax.persistence.EntityNotFoundException；
导入javax.persistence.criteria.CriteriaQuery；
导入javax.persistence.criteria.Root；
import uk.co.utel.dataaccess.entities.B；
导入java.util.ArrayList；
导入java.util.List；
导入javax.persistence.EntityManager；
导入javax.persistence.EntityManagerFactory；
导入uk.co.utel.dataaccess.controllers.exceptions.IllegalOrphaneException；
导入uk.co.utel.dataaccess.controllers.exceptions.NonexistentEntityException；
import uk.co.utel.dataaccess.entities.A；
公共类AJpaController实现可序列化{
公共AJPAC控制器（EntityManagerFactory emf）{
this.emf=emf；
}
私有EntityManagerFactory emf=null；
公共实体管理器getEntityManager（）{
返回emf.createEntityManager（）；
}
公共作废创建（A）{
如果（a.getBList（）==null）{
a、 setBList（新的ArrayList（））；
}
EntityManager em=null；
试一试{
em=getEntityManager（）；
em.getTransaction（）.begin（）；
List attachedBList=new ArrayList（）；
对于（B bListBToAttach:a.getBList（））{
bListBToAttach=em.getReference（bListBToAttach.getClass（），bListBToAttach.getId（））；
附件列表。添加（bListBToAttach）；
}
a、 挫折清单（附件）；
对于（B bListB:a.getBList（））{
A oldaidOfListB=bListB.getAId（）；
b.设置辅助（a）；
bListB=em.merge（bListB）；
if（oldaidOfListB！=null）{
oldAIdOfBListB.getBList（）.remove（bListB）；
OldAidOfListB=em.merge（OldAidOfListB）；
}
}
em.getTransaction（）.commit（）；
}最后{
如果（em！=null）{
em.close（）；
}
}
}
public void edit（A）抛出非法孤儿异常、不存在实体异常、异常{
EntityManager em=null；
试一试{
em=getEntityManager（）；
em.getTransaction（）.begin（）；
persistentA=em.find（A.class，A.getId（））；
List bListOld=persistentA.getBList（）；
List bListNew=a.getBList（）；
列表非法消息=null；
对于（B bListOld B:bListOld）{
如果（！bListNew.contains（bListOldB））{
if（illegalOrphanMessages==null）{
illegalOrphanMessages=新ArrayList（）；
}
添加（“您必须保留B”+bListOldB+，因为其辅助字段不可为空。”）；
}
}
if（非法消息！=null）{
抛出新的非法孤儿异常（非法孤儿消息）；
}
List AttachedListNew=new ArrayList（）；
对于（B BlistNewToAttach:bListNew）{
bListNewBToAttach=em.getReference（bListNewBToAttach.getClass（），bListNewBToAttach.getId（））；
attachedBListNew.add（blistnewbatach）；
}
bListNew=attachedBListNew；
a、 挫折清单（bListNew）；
对于（B bListNewB:bListNew）{
如果（！bListOld.contains（bListNewB））{
OldAidOfListNewb=bListNewB.getAId（）；
bListNewB.setAId（a）；
bListNewB=em.merge（bListNewB）；
如果（OldAidOfListNewb！=null&！OldAidOfListNewb.equals（a））{
oldAIdOfBListNewB.getBList（）.remove（bListNewB）；
OldAidOfListNewb=em.merge（OldAidOfListNewb）；
}
}
}
em.getTransaction（）.commit（）；
}捕获（例外情况除外）{
字符串msg=ex.getLocalizedMessage（）；
如果（msg==null | | msg.length（）==0）{
Long id=a.getId（）；
if（findA（id）==null）{
抛出新的NoneExistentEntityException（“id为“+id+”的a不再存在”）；
}
}
掷骰子；
}最后{
如果（em！=null）{
em.close（）；
}
}
}
public void destroy（长id）引发IllegalOrphanException、NoneExistentEntityException{
EntityManager em=null；
试一试{
em=getEntityManager（）；
em.getTransaction（）.begin（）；
A A；
试一试{
a=em.getReference（a.class，id）；
a、 getId（）；
}捕获（EntityNotFoundException enfe）{
抛出新的不存在实体异常（“id为“+id+”的a不再存在。”，enfe）；
}
列表非法消息=null；
List bListOrphanCheck=a.getBList（）；
对于（B bListOrphanCheck B:bListOrphanCheck）{
如果（非法）消息==
package test.controllers;
import java.io.Serializable;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import uk.co.utel.dataaccess.entities.B;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import uk.co.utel.dataaccess.controllers.exceptions.IllegalOrphanException;
import uk.co.utel.dataaccess.controllers.exceptions.NonexistentEntityException;
import uk.co.utel.dataaccess.entities.A;
public class AJpaController implements Serializable {
public AJpaController(EntityManagerFactory emf) {
this.emf = emf;
}
private EntityManagerFactory emf = null;
public EntityManager getEntityManager() {
return emf.createEntityManager();
}
public void create(A a) {
if (a.getBList() == null) {
a.setBList(new ArrayList<B>());
}
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
List<B> attachedBList = new ArrayList<B>();
for (B bListBToAttach : a.getBList()) {
bListBToAttach = em.getReference(bListBToAttach.getClass(), bListBToAttach.getId());
attachedBList.add(bListBToAttach);
}
a.setBList(attachedBList);
for (B bListB : a.getBList()) {
A oldAIdOfBListB = bListB.getAId();
bListB.setAId(a);
bListB = em.merge(bListB);
if (oldAIdOfBListB != null) {
oldAIdOfBListB.getBList().remove(bListB);
oldAIdOfBListB = em.merge(oldAIdOfBListB);
}
}
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public void edit(A a) throws IllegalOrphanException, NonexistentEntityException, Exception {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
A persistentA = em.find(A.class, a.getId());
List<B> bListOld = persistentA.getBList();
List<B> bListNew = a.getBList();
List<String> illegalOrphanMessages = null;
for (B bListOldB : bListOld) {
if (!bListNew.contains(bListOldB)) {
if (illegalOrphanMessages == null) {
illegalOrphanMessages = new ArrayList<String>();
}
illegalOrphanMessages.add("You must retain B " + bListOldB + " since its aId field is not nullable.");
}
}
if (illegalOrphanMessages != null) {
throw new IllegalOrphanException(illegalOrphanMessages);
}
List<B> attachedBListNew = new ArrayList<B>();
for (B bListNewBToAttach : bListNew) {
bListNewBToAttach = em.getReference(bListNewBToAttach.getClass(), bListNewBToAttach.getId());
attachedBListNew.add(bListNewBToAttach);
}
bListNew = attachedBListNew;
a.setBList(bListNew);
for (B bListNewB : bListNew) {
if (!bListOld.contains(bListNewB)) {
A oldAIdOfBListNewB = bListNewB.getAId();
bListNewB.setAId(a);
bListNewB = em.merge(bListNewB);
if (oldAIdOfBListNewB != null && !oldAIdOfBListNewB.equals(a)) {
oldAIdOfBListNewB.getBList().remove(bListNewB);
oldAIdOfBListNewB = em.merge(oldAIdOfBListNewB);
}
}
}
em.getTransaction().commit();
} catch (Exception ex) {
String msg = ex.getLocalizedMessage();
if (msg == null || msg.length() == 0) {
Long id = a.getId();
if (findA(id) == null) {
throw new NonexistentEntityException("The a with id " + id + " no longer exists.");
}
}
throw ex;
} finally {
if (em != null) {
em.close();
}
}
}
public void destroy(Long id) throws IllegalOrphanException, NonexistentEntityException {
EntityManager em = null;
try {
em = getEntityManager();
em.getTransaction().begin();
A a;
try {
a = em.getReference(A.class, id);
a.getId();
} catch (EntityNotFoundException enfe) {
throw new NonexistentEntityException("The a with id " + id + " no longer exists.", enfe);
}
List<String> illegalOrphanMessages = null;
List<B> bListOrphanCheck = a.getBList();
for (B bListOrphanCheckB : bListOrphanCheck) {
if (illegalOrphanMessages == null) {
illegalOrphanMessages = new ArrayList<String>();
}
illegalOrphanMessages.add("This A (" + a + ") cannot be destroyed since the B " + bListOrphanCheckB + " in its bList field has a non-nullable aId field.");
}
em.remove(a);
em.getTransaction().commit();
} finally {
if (em != null) {
em.close();
}
}
}
public List<A> findAEntities() {
return findAEntities(true, -1, -1);
}
public List<A> findAEntities(int maxResults, int firstResult) {
return findAEntities(false, maxResults, firstResult);
}
private List<A> findAEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(A.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
public A findA(Long id) {
EntityManager em = getEntityManager();
try {
return em.find(A.class, id);
} finally {
em.close();
}
}
public int getACount() {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
Root<A> rt = cq.from(A.class);
cq.select(em.getCriteriaBuilder().count(rt));
Query q = em.createQuery(cq);
return ((Long) q.getSingleResult()).intValue();
} finally {
em.close();
}
}
}