java – 添加两个变量后的BeanCreationException
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有人可以告诉我如何通过BeanCreationException？
我将两个变量添加到Owner.java后得到BeanCreationException,如下所示：
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> pets;
//I added the following two variable declarations
@Transient
private Set<Pet> cats = new HashSet<Pet>();
@Transient
private Set<Pet> dogs = new HashSet<Pet>();
我还为猫和狗添加了getter和setter方法,以及将猫和狗作为宠物子集填充的方法,如下所示：
public void parsePets() {
for (Pet pet : getPetsInternal()) {
if (pet.getType().getName().equals("cat")) {cats.add(pet);}
else if (pet.getType().getName().equals("dog")) {dogs.add(pet);}
}
}
protected Set<Pet> getPetsInternal() {
if (this.pets == null) {this.pets = new HashSet<Pet>();}
return this.pets;
}
当我执行Run As时,应用程序无法初始化…在eclipse中运行服务器,并提供以下错误消息：
org.springframework.beans.factory.BeanCreationException:
Error creating bean with name
'org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor#0'
defined in class path resource [spring/business-config.xml]: Initialization of bean failed;
nested exception is org.springframework.beans.factory.BeanCreationException:
Error creating bean with name 'entityManagerFactory' defined in class path resource
[spring/business-config.xml]: Invocation of init method failed;
nested exception is javax.persistence.PersistenceException:
[PersistenceUnit: petclinic] Unable to build EntityManagerFactory
...
Caused by: org.hibernate.MappingException:
Could not determine type for:
java.util.Set, at table: owners, for columns:
[org.hibernate.mapping.Column(cats)]
这是the code for business-config.xml.
我可以通过注释掉更改消除错误消息并让应用程序运行,但是我留下了三个列表(宠物,猫,狗)是相同的问题,当我需要猫和狗时,每个都不同宠物的子集.这是代码,它消除了错误消息,但创建了三个相同的列表,这些列表不应该相同：
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> pets;
//I added next two variables
// @Transient
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> cats;// = new HashSet<Pet>();
// @Transient
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> dogs;// = new HashSet<Pet>();
根据axiopisty的要求,除了添加猫和狗之外,我无法评论所有内容,因为从OwnerController.java调用宠物,猫和狗,如下所示：
@RequestMapping(value = "/owners", method = RequestMethod.GET)
public String processFindForm(@RequestParam("ownerID") String ownerId, Owner owner, BindingResult result, Map<String, Object> model) {
Collection<Owner> results = this.clinicService.findOwnerByLastName("");
model.put("selections", results);
int ownrId = Integer.parseInt(ownerId);
Owner sel_owner = this.clinicService.findOwnerById(ownrId);//jim added this
sel_owner.parsePets();
model.put("sel_owner",sel_owner);
return "owners/ownersList";
}
编辑：
根据Sotirios的请求,这是我的实体类Owner.java：
@Entity
@Table(name = "owners")
public class Owner extends Person {
@Column(name = "address")
@NotEmpty
private String address;
@Column(name = "city")
@NotEmpty
private String city;
@Column(name = "telephone")
@NotEmpty
@Digits(fraction = 0, integer = 10)
private String telephone;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> pets;
//I added next two variables
@Transient
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> cats = new HashSet<Pet>();
@Transient
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> dogs = new HashSet<Pet>();
//end of 2 variables I added
public String getAddress() {return this.address;}
public void setAddress(String address) {this.address = address;}
public String getCity() {return this.city;}
public void setCity(String city) {this.city = city;}
public String getTelephone() {return this.telephone;}
public void setTelephone(String telephone) {this.telephone = telephone;}
protected void setPetsInternal(Set<Pet> pets) {this.pets = pets;}
// Call this from OwnerController before returning data to page.
public void parsePets() {
for (Pet pet : getPetsInternal()) {
if (pet.getType().getName().equals("cat")) {
cats.add(pet);
System.out.println(pet.getType().getName());
System.out.println("cats.size() is: "+cats.size());
System.out.println("added a cat to cats");
}
else if (pet.getType().getName().equals("dog")) {
dogs.add(pet);
System.out.println(pet.getType().getName());
System.out.println("dogs.size() is: "+dogs.size());
System.out.println("added a dog to dogs");
}
// add as many as you want
System.out.println("----------------------------------------------");
}
}
public Set<Pet> getCats() {
System.out.println("about to return cats");
for (Pet cat : cats) {System.out.println("counting a "+cat.getType()+" in cats.");}
System.out.println("cats.size() is: "+cats.size());
return cats;
}
public Set<Pet> getDogs() {
System.out.println("about to return dogs");
for (Pet dog : dogs) {System.out.println("counting a "+dog.getType()+" in dogs.");}
System.out.println("dogs.size() is: "+dogs.size());
return dogs;
}
//end section I added
protected Set<Pet> getPetsInternal() {
if (this.pets == null) {this.pets = new HashSet<Pet>();}
return this.pets;
}
public List<Pet> getPets() {
List<Pet> sortedPets = new ArrayList<Pet>(getPetsInternal());
PropertyComparator.sort(sortedPets, new MutableSortDefinition("name", true, true));
return Collections.unmodifiableList(sortedPets);
}
public void addPet(Pet pet) {
getPetsInternal().add(pet);
pet.setOwner(this);
}
public Pet getPet(String name) {return getPet(name, false);}
public Pet getPet(String name, boolean ignoreNew) {
name = name.toLowerCase();
for (Pet pet : getPetsInternal()) {
if (!ignoreNew || !pet.isNew()) {
String compName = pet.getName();
compName = compName.toLowerCase();
if (compName.equals(name)) {
return pet;
}
}
}
return null;
}
@Override
public String toString() {
return new ToStringCreator(this)
.append("id", this.getId())
.append("new", this.isNew())
.append("lastName", this.getLastName())
.append("firstName", this.getFirstName())
.append("address", this.address)
.append("city", this.city)
.append("telephone", this.telephone)
.toString();
}
}
解决方法:
为什么单独的列表必须是实例变量？！为什么不简单地创建一个getCats方法(以及其他方法)并简单地过滤宠物集合？试图映射所有东西会使imho变得过于复杂.
@Entity
@Table(name = "owners")
public class Owner extends Person {
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> pets;
public Set<Pet> getCats() {
Set<Pet> cats = new HashSet<Pet>();
for (Pet pet : getPetsInternal()) {
if (pet.getType().getName().equals("cat")) {
cats.add(pet);
}
}
return cats;
}
}
缺点是每次需要时都会重新创建集合.您可以使用Google Guava等功能轻松完成此操作并创建过滤器列表.
@Entity
@Table(name = "owners")
public class Owner extends Person {
@OneToMany(cascade = CascadeType.ALL, mappedBy = "owner", fetch=FetchType.EAGER)
private Set<Pet> pets;
public Set<Pet> getCats() {
return Sets.filter(getPetsInternal(), new Predicate<Pet>() {
public boolean apply(Pet pet) {
return pet.getType().getName().equals("cat")
}
});
}
}
您也可以在parsePets方法中进行操作,并使用@PostLoad对其进行注释,以便在所有者从数据库中检索后调用该方法.
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