持久化对象jpa时的java.lang.StackOverflower错误
我正在使用JPA、JSF、EJB和Derby构建一个应用程序。此时,应用程序仍然很小。我在申请表中有一个添加新产品的表格。当向数据库添加数据时,在我重新启动应用程序或服务器之前,一切都会顺利进行。当我重新启动服务器或应用程序时,我得到了java.lang.StackOverflowerError,我仍然可以查询数据库中由产品数据库表示的数据,但无法创建产品。到目前为止,我在db中只有5个条目,但我担心这会发生得太早 这就是Ejb(为了简单起见删除了Getter、setter和构造函数):持久化对象jpa时的java.lang.StackOverflower错误,java,jpa,persistence,ejb-3.0,Java,Jpa,Persistence,Ejb 3.0,我正在使用JPA、JSF、EJB和Derby构建一个应用程序。此时,应用程序仍然很小。我在申请表中有一个添加新产品的表格。当向数据库添加数据时,在我重新启动应用程序或服务器之前,一切都会顺利进行。当我重新启动服务器或应用程序时,我得到了java.lang.StackOverflowerError,我仍然可以查询数据库中由产品数据库表示的数据,但无法创建产品。到目前为止,我在db中只有5个条目,但我担心这会发生得太早 这就是Ejb(为了简单起见删除了Getter、setter和构造函数): @无状
@无状态
公共类ProductEJB{
@PersistenceContext(unitName=“luavippu”)
私人实体管理者;
公共列表findAllProducts()
{
TypedQuery query=em.createNamedQuery(“findAllProducts”,Product.class);
返回query.getResultList();
}
公共产品findProductById(int productId)
{
返回em.find(Product.class,productId);
}
公共产品createProduct(产品产品)
{
product.setDateAdded(productCreationDate());
em.persist(产品);
退货产品;
}
公共无效更新产品(产品产品)
{
em.merge(产品);
}
公共产品(产品)
{
product=em.find(product.class,product.getProduct_id());
em.remove(em.merge(product));
}
这是ProductController(为了简单起见删除了Getter、setter和构造函数):
@Named
@请求范围
公共类产品控制器{
@EJB
私有产品ejb ProductEJB;
@EJB
私人类别jb categoryjb;
私人产品=新产品();
private List productList=new ArrayList();
私人类别;
private List categoryList=new ArrayList();
公共字符串doCreateProduct()
{
product=productEjb.createProduct(产品);
productList=productEjb.findAllProducts();
返回“listProduct?faces redirect=true”;
}
公共字符串dodeletProduct()
{
productEjb.deleteProduct(产品);
返回“deleteProduct?faces redirect=true”;
}
公共字符串cancelDeleteAction()
{
返回“listProduct?faces redirect=true”;
}
@施工后
公共void init()
{
categoryList=categoryEjb.findAllCategory();
productList=productEjb.findAllProducts();
}
类别实体(为了简单起见,删除了getter、setter、hash()和构造函数):
@实体
@命名查询({
@NamedQuery(name=“findAllCategory”,query=“从类别c中选择c”)
})
公共类类别实现可序列化
{
私有静态最终长serialVersionUID=1L;
@Id@GeneratedValue(策略=GenerationType.AUTO)
私有int类_id;
私有字符串名称;
私有字符串描述;
@OneToMany(mappedBy=“category_fk”)
私有列表产品;
//readObject()和writeObject()
私有void readObject(ObjectInputStream ois)抛出IOException、ClassNotFoundException
{
//默认反序列化程序
ois.defaultReadObject();
//阅读属性
category_id=ois.readInt();
name=(字符串)ois.readObject();
description=(字符串)ois.readObject();
}
私有void writeObject(ObjectOutputStream oos)抛出IOException、ClassNotFoundException
{
//默认序列化程序
oos.defaultWriteObject();
//写属性
oos.writeInt(类别标识);
oos.writeObject(名称);
oos.writeObject(描述);
}
@凌驾
公共布尔等于(对象obj){
if(obj==null){
返回false;
}
如果(getClass()!=obj.getClass()){
返回false;
}
最终类别其他=(类别)obj;
if(this.category\u id!=其他.category\u id){
返回false;
}
如果((this.name==null)?(other.name!=null):!this.name.equals(other.name)){
返回false;
}
如果((this.description==null)?(other.description!=null):!this.description.equals(other.description)){
返回false;
}
如果(this.product_fk!=other.product_fk&&(this.product_fk==null|||!this.product_fk.equals(other.product_fk))){
返回false;
}
返回true;
}
产品实体(为了简单起见,删除了getter、setter、hash()和构造函数):
@实体
@命名查询({
@NamedQuery(name=“findAllProducts”,query=“从产品p中选择p”)
})
公共类产品实现可序列化
{
私有静态最终长serialVersionUID=1L;
@Id@GeneratedValue(策略=GenerationType.AUTO)
私有int产品标识;
私有字符串名称;
私有字符串描述;
受保护的字节[]映像文件;
私人浮动价格;
@时态(TemporalType.TIMESTAMP)
已添加私人日期;
@许多酮
私人类别(fk),;
@许多酮
私人销售详情;
//readObject()和writeObject()方法
私有void readObject(ObjectInputStream ois)抛出IOException、ClassNotFoundException
{
//默认反序列化
ois.defaultReadObject();
//阅读属性
product_id=ois.readInt();
name=(字符串)ois.readObject();
description=(字符串)ois.readObject();
对于(int i=0;i问题似乎出在Category类中-equals做了一些事情,反过来调用equals,创建了一个无休止的循环我怀疑循环依赖性是问题的根本原因。我认为您已经在Category
或SaleDetails
或两者中映射了产品
s、 如果是,它将呼叫cir
@Stateless
public class ProductEJB{
@PersistenceContext(unitName = "luavipuPU")
private EntityManager em;
public List<Product> findAllProducts()
{
TypedQuery<Product> query = em.createNamedQuery("findAllProducts", Product.class);
return query.getResultList();
}
public Product findProductById(int productId)
{
return em.find(Product.class, productId);
}
public Product createProduct(Product product)
{
product.setDateAdded(productCreationDate());
em.persist(product);
return product;
}
public void updateProduct(Product product)
{
em.merge(product);
}
public void deleteProduct(Product product)
{
product = em.find(Product.class, product.getProduct_id());
em.remove(em.merge(product));
}
@Named
@RequestScoped
public class ProductController {
@EJB
private ProductEJB productEjb;
@EJB
private CategoryEJB categoryEjb;
private Product product = new Product();
private List<Product> productList = new ArrayList<Product>();
private Category category;
private List<Category> categoryList = new ArrayList<Category>();
public String doCreateProduct()
{
product = productEjb.createProduct(product);
productList = productEjb.findAllProducts();
return "listProduct?faces-redirect=true";
}
public String doDeleteProduct()
{
productEjb.deleteProduct(product);
return "deleteProduct?faces-redirect=true";
}
public String cancelDeleteAction()
{
return "listProduct?faces-redirect=true";
}
@PostConstruct
public void init()
{
categoryList = categoryEjb.findAllCategory();
productList = productEjb.findAllProducts();
}
@Entity
@NamedQueries({
@NamedQuery(name= "findAllCategory", query="SELECT c FROM Category c")
})
public class Category implements Serializable
{
private static final long serialVersionUID = 1L;
@Id @GeneratedValue(strategy= GenerationType.AUTO)
private int category_id;
private String name;
private String description;
@OneToMany(mappedBy = "category_fk")
private List<Product> product_fk;
// readObject() and writeObject()
private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException
{
// default deserializer
ois.defaultReadObject();
// read the attributes
category_id = ois.readInt();
name = (String)ois.readObject();
description = (String)ois.readObject();
}
private void writeObject(ObjectOutputStream oos) throws IOException, ClassNotFoundException
{
// default serializer
oos.defaultWriteObject();
// write the attributes
oos.writeInt(category_id);
oos.writeObject(name);
oos.writeObject(description);
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Category other = (Category) obj;
if (this.category_id != other.category_id) {
return false;
}
if ((this.name == null) ? (other.name != null) : !this.name.equals(other.name)) {
return false;
}
if ((this.description == null) ? (other.description != null) : !this.description.equals(other.description)) {
return false;
}
if (this.product_fk != other.product_fk && (this.product_fk == null || !this.product_fk.equals(other.product_fk))) {
return false;
}
return true;
}
@Entity
@NamedQueries({
@NamedQuery(name="findAllProducts", query = "SELECT p from Product p")
})
public class Product implements Serializable
{
private static final long serialVersionUID = 1L;
@Id @GeneratedValue(strategy= GenerationType.AUTO)
private int product_id;
private String name;
private String description;
protected byte[] imageFile;
private Float price;
@Temporal(TemporalType.TIMESTAMP)
private Date dateAdded;
@ManyToOne
private Category category_fk;
@ManyToOne
private SaleDetails saleDetails_fk;
// readObject() and writeObject() methods
private void readObject (ObjectInputStream ois)throws IOException, ClassNotFoundException
{
// default deserialization
ois.defaultReadObject();
// read the attributes
product_id = ois.readInt();
name = (String)ois.readObject();
description = (String)ois.readObject();
for(int i=0; i<imageFile.length; i++ )
{
imageFile[i]=ois.readByte();
}
price = ois.readFloat();
dateAdded = (Date)ois.readObject();
category_fk = (Category)ois.readObject();
saleDetails_fk = (SaleDetails)ois.readObject();
}
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Product other = (Product) obj;
if (this.product_id != other.product_id) {
return false;
}
if ((this.name == null) ? (other.name != null) : !this.name.equals(other.name)) {
return false;
}
if ((this.description == null) ? (other.description != null) : !this.description.equals(other.description)) {
return false;
}
if (!Arrays.equals(this.imageFile, other.imageFile)) {
return false;
}
if (this.price != other.price && (this.price == null || !this.price.equals(other.price))) {
return false;
}
if (this.dateAdded != other.dateAdded && (this.dateAdded == null || !this.dateAdded.equals(other.dateAdded))) {
return false;
}
if (this.category_fk != other.category_fk && (this.category_fk == null || !this.category_fk.equals(other.category_fk))) {
return false;
}
if (this.saleDetails_fk != other.saleDetails_fk && (this.saleDetails_fk == null || !this.saleDetails_fk.equals(other.saleDetails_fk))) {
return false;
}
return true;
}
private void writeObject(ObjectOutputStream oos) throws IOException, ClassNotFoundException
{
// default serialization
oos.defaultWriteObject();
// write object attributes
oos.writeInt(product_id);
oos.writeObject(name);
oos.writeObject(description);
oos.write(imageFile);
oos.writeFloat(price);
oos.writeObject(dateAdded);
oos.writeObject(category_fk);
oos.writeObject(saleDetails_fk);
}
javax.faces.el.EvaluationException: java.lang.StackOverflowError
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.StackOverflowError
at java.util.Vector$Itr.<init>(Vector.java:1120)
at java.util.Vector.iterator(Vector.java:1114)
at java.util.AbstractList.hashCode(AbstractList.java:540)
at java.util.Vector.hashCode(Vector.java:988)
at org.eclipse.persistence.indirection.IndirectList.hashCode(IndirectList.java:460)
at com.lv.Entity.Category.hashCode(Category.java:96)
at com.lv.Entity.Product.hashCode(Product.java:148)
at java.util.AbstractList.hashCode(AbstractList.java:541)
private void writeObject(ObjectOutputStream oos) throws IOException {
// default serialization
oos.defaultWriteObject();
// write the object attributes
oos.writeInt(product_id);
oos.writeObject(name);
oos.writeObject(description);
oos.write(imageFile);
oos.writeFloat(price);
oos.writeObject(dateAdded);
oos.writeObject(category_fk);
oos.writeObject(saleDetails_fk);
}
private void readObject(ObjectInputStream ois)
throws ClassNotFoundException, IOException {
// default deserialization
ois.defaultReadObject();
//read the attributes
product_id = ois.readInt();
name = (String)ois.readObject();
description = (String)ois.readObject();
imageFile = ois.read();
price = ois.readFloat();
dateAdded = (Date)ois.readObject();
category_fk = (Category)ois.readObject();
saleDetails_fk = (SaleDetails)ois.readObject();
}
if (this.product_fk != other.product_fk && (this.product_fk == null || !this.product_fk.equals(other.product_fk))) {
return false;
}
if (this.category_fk != other.category_fk && (this.category_fk == null || !this.category_fk.equals(other.category_fk))) {
return false;
}
public class Category implements Serializable
{
...
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
if ((this.name == null) ? (other.name != null) : !this.name.equals(other.name)) {
return false;
}
if ((this.description == null) ? (other.description != null) : !this.description.equals(other.description)) {
return false;
}
return true;
}
}
session.startTransaction();
Category electronics = session.get(Category.class, 1234);
Set<Product> products = electronics.getProducts();
session.commit();
Product camera = product.get(0);
camera.setPrice("300");
products.add(camera);