小面片应用程序中的javax.persistence.TransactionRequiredException [英] javax.persistence.TransactionRequiredException in small facelet application
本文介绍了小面片应用程序中的javax.persistence.TransactionRequiredException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试从小型facelet应用程序中将某些值保留到MySql数据库，但不断收到此错误。我有一个JPS页面和一个servlet的相同的应用程序，它与大致相同的逻辑工作得很好，这是我第一次尝试使用facelets所以它可能只是一些愚蠢的东西，但我会帮助你。
I'm trying to persist some values to a MySql database from a small facelet application but keep getting this error. I had this same application with a JPS page and a servlet and it worked fine with roughly the same logic, this is my first time trying to work with facelets so it might just be something silly but i'd appriciate the help.
谢谢
错误
javax.faces.el.EvaluationException: javax.persistence.TransactionRequiredException
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$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)
Caused by: javax.persistence.TransactionRequiredException
at com.sun.enterprise.container.common.impl.EntityManagerWrapper.doTxRequiredCheck(EntityManagerWrapper.java:163)
at com.sun.enterprise.container.common.impl.EntityManagerWrapper.doTransactionScopedTxCheck(EntityManagerWrapper.java:145)
at com.sun.enterprise.container.common.impl.EntityManagerWrapper.persist(EntityManagerWrapper.java:263)
at vecka19.controller.BookController.addBook(BookController.java:28)
at vecka19.controller.BookController$Proxy$_$$_WeldClientProxy.addBook(BookController$Proxy$_$$_WeldClientProxy.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at javax.el.BeanELResolver.invokeMethod(BeanELResolver.java:779)
at javax.el.BeanELResolver.invoke(BeanELResolver.java:528)
at javax.el.CompositeELResolver.invoke(CompositeELResolver.java:257)
at com.sun.el.parser.AstValue.invoke(AstValue.java:248)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:302)
at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:39)
at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
... 32 more
index .xhtml
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:c="http://java.sun.com/jsp/jstl/core">
<h:head>
<title>Vecka19</title>
</h:head>
<h:body>
<section id="bookForm">
<div>
<h:form id="bookForm">
<table>
<tr>
<td><h:outputLabel value="ID: " for="id"/></td>
<td><h:inputText id="id" value="#{book.bookId}"/></td>
</tr>
<tr>
<td><h:outputLabel value="TITLE: " for="title"/></td>
<td><h:inputText id="title" value="#{book.title}"/></td>
</tr>
<tr>
<td><h:outputLabel value="AUTHOR: " for="author"/></td>
<td><h:inputText id="author" value="#{book.author}"/></td>
</tr>
<tr>
<td><h:outputLabel value="PRICE: " for="price"/></td>
<td><h:inputText id="price" value="#{book.price}"/></td>
</tr>
<tr>
<td>
<h:commandButton value="Add" action="#{bookController.addBook()}" />
<h:commandButton value="Get" action="#{bookController.book}" />
<h:commandButton value="Edit" action="#{bookController.editBook()}" />
<h:commandButton value="Delete" action="#{bookController.deleteBook()}" />
</td>
</tr>
</table>
</h:form>
</div>
</section>
<br />
<section id="dbTable">
<div>
<table>
<th>ID</th>
<th>TITLE</th>
<th>AUTHOR</th>
<th>PRICE</th>
<c:forEach items="${bookController.books}" var="book">
<tr>
<td>${book.bookId}</td>
<td>${book.title}</td>
<td>${book.author}</td>
<td>${book.price}</td>
</tr>
</c:forEach>
</table>
</div>
</section>
</h:body>
BookController.java
package vecka19.controller;
import java.util.List;
import javax.enterprise.context.RequestScoped;
import javax.inject.Inject;
import javax.inject.Named;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import vecka19.model.Book;
@Named
@RequestScoped
public class BookController {
@Inject Book book;
@PersistenceContext
private EntityManager em;
public List getBooks() {
return em.createNamedQuery("Book.findAll").getResultList();
}
public Book getBook() {
return em.find(Book.class, book.getBookId());
}
public void addBook() {
em.persist(book);
}
public void editBook() {
em.merge(book);
}
public void deleteBook() {
em.remove(getBook());
}
}
Book.java
package vecka19.model;
import java.io.Serializable;
import javax.enterprise.context.RequestScoped;
import javax.inject.Named;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;
@Entity
@Named
@RequestScoped
@Table(name = "BOOKS")
@NamedQueries({@NamedQuery(name = "Book.findAll", query = "SELECT b FROM Book b")})
public class Book implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@NotNull
@Column(name = "BOOK_ID")
private Integer bookId;
@Column(name = "TITLE")
private String title;
@Column(name = "AUTHOR")
private String author;
@Column(name = "PRICE")
private Integer price;
public Book() {
}
public Book(Integer bookId) {
this.bookId = bookId;
}
public Integer getBookId() {
return bookId;
}
public void setBookId(Integer bookId) {
this.bookId = bookId;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public Integer getPrice() {
return price;
}
public void setPrice(Integer price) {
this.price = price;
}
}
percistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
<persistence-unit name="vecka19PU" transaction-type="JTA">
<jta-data-source>jdbc/MySQLDataSource</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties/>
</persistence-unit>
</persistence>
推荐答案
您滥用CDI托管bean作为企业服务。它没有交易管理的线索。您需要手动管理交易。由于这通常是一种痛苦，并且您显然正在使用Glassfish，它是一个支持EJB的全面Java EE容器，因此您更愿意使用一个值得一提的EJB。在EJB中使用 EntityManager 时，容器将完全透明地管理数据库事务。一个EJB方法调用计为单个事务（即，当您触发多个数据库查询并且其中一个失败时，所有内容都将自动回滚）。
You're abusing a CDI managed bean as a business service. It has no clues of transaction management. You'd need to manually manage transactions. As this is usually a pain and you're apparently using Glassfish, which is a fullworthy Java EE container supporting EJBs, you'd rather like to use a fullworthy EJB for this. When using EntityManager inside an EJB, the container will fully transparently manage DB transactions. One EJB method call counts as a single transaction (i.e. when you fire multiple DB queries and one of them fails, then everything will be automatically rolled back).
总的来说，您似乎在混合模型，控制器和服务的职责。不要将您的实体设置为托管bean。您还应该绝对不要在Javabean getter方法中执行业务逻辑（例如 getBooks（））。在迭代组件中引用时，它会在每次迭代循环期间调用。所以想象你有100条记录，然后数据库会被击中100次。这是非常低效的。
Overall, you seem to be mixing the responsibilities of the model, controller and service. Do not make your entity a managed bean as well. You should further absolutely also not perform business logic in a Javabean getter method (e.g. getBooks()). When referenced in an iterating component, it's invoked during every iteration round. So imagine that you've 100 records, then the DB will be hit 100 times. This is plain inefficient.
以下是它们的外观：
模型（实体）：
@Entity
@Table(name = "BOOKS")
public class Book implements Serializable {
// ...
}
控制器（支持bean）：
Controller (the backing bean):
@Named
@RequestScoped
public class BookController {
private Book book;
private List<Book> books;
@EJB
private BookService service;
@PostConstruct
public void init() {
book = new Book();
books = service.list();
}
public void add() {
service.save(book);
init();
}
public Book getBook() {
return book;
}
public List<Book> getBooks() {
return books;
}
}
服务（EJB）：
@Stateless
public class BookService {
@PersistenceContext
private EntityManager em;
public List<Book> list() {
return em.createQuery("FROM Book", Book.class).getResultList();
}
public Book find(Integer id) {
return em.find(Book.class, id);
}
public Integer save(Book book) {
em.persist(book);
return book.getId();
}
public void update(Book book) {
em.merge(book);
}
public void delete(Book book) {
em.remove(em.contains(book) ? book : em.merge(book));
}
}
查看（Facelet;简化） ：
View (the Facelet; simplified):
<h:inputText id="title" value="#{bookController.book.title}"/>
<h:inputText id="author" value="#{bookController.book.author}"/>
<h:inputText id="price" value="#{bookController.book.price}"/>
<h:commandButton value="Add" action="#{bookController.add}" />
...
<h:dataTable value="#{bookController.books}" var="book">
<h:column><f:facet name="header">ID</f:facet>#{book.id}</h:column>
<h:column><f:facet name="header">Title</f:facet>#{book.title}</h:column>
<h:column><f:facet name="header">Author</f:facet>#{book.author}</h:column>
<h:column><f:facet name="header">Price</f:facet>#{book.price}</h:column>
</h:dataTable>
（你的编辑和删除按钮没有任何意义，所以我删除了它们，你可能想把它们放在数据表中）
- Recommended JSF 2.0 CRUD frameworks
- Why JSF calls getters multiple times
这篇关于小面片应用程序中的javax.persistence.TransactionRequiredException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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