小面应用程序中的javax.persistence.TransactionRequiredException

齐元章

2023-03-14

问题内容：

我试图从一个小的facelet应用程序中将一些值持久化到MySql数据库中，但一直收到此错误。我有一个具有JPS页面和servlet的相同应用程序，并且在大致相同的逻辑下也可以正常工作，这是我第一次尝试使用facelets，因此可能只是愚蠢的事情，但我会寻求帮助。

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>

问题答案：

您正在滥用CDI管理的bean作为业务服务。它没有交易管理的线索。您需要手动管理交易。因为通常这很麻烦，而且您显然使用的是Glassfish，它是支持EJB的完全有价值的Java
EE容器，所以您希望为此使用完全有价值的EJB。在EntityManagerEJB内部使用时，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而其中一个失败时，所有内容将自动回滚）。

总的来说，您似乎混用了模型，控制器和服务的职责。也不要使您的实体成为托管bean。您还应该绝对不要在Javabean的getter方法中执行业务逻辑（例如getBooks()）。在迭代组件中引用时，将在每个迭代回合中调用它。因此，假设您有100条记录，那么数据库将被命中100次。这显然是低效的。

看起来应该像这样：

模型（实体）：

@Entity
@Table(name = "BOOKS")
public class Book implements Serializable {
    // ...
}

控制器（辅助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));
    }

}

视图（Facelet；简化）：

<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>

（您的编辑和删除按钮没有任何意义，因此我将其删除了，您可能希望将其放入数据表中）

小面应用程序中的javax.persistence.TransactionRequiredException

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