相关疑难解决方法(0)

我正在使用Wildfly 10.0.0 Final,Java EE7,Maven和JPA 2.1.当我查询我的数据库中的记录时,它工作正常并列出了员工,但是当我试图坚持一个新员工时,它给了我以下异常:

javax.servlet.ServletException: WFLYJPA0060: Transaction is required to perform this operation (either use a transaction or extended persistence context)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:671)
io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
...

我正在尝试使用JSF和CDI bean来实现它.我有一个JTA数据源,我在persistence.xml文件中配置了它:

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" version="2.1">
    <persistence-unit name="MyPersistenceUnit">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <jta-data-source>java:/EmployeesDS</jta-data-source>
        <class>com.home.entity.Employee</class>
        <properties>
            <property name="hibernate.archive.autodetection" value="class"/>
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.format_sql" value="true"/>
            <property name="hbm2ddl.auto" value="update"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
        </properties>
    </persistence-unit>
</persistence>

CDI bean可以在下面看到.它相对简单,有一种方法可以列出25名员工,另一种方法可以保留特定员工:

@Named
@RequestScoped
public class DataFetchBean {
    @PersistenceContext
    EntityManager em;

    public List getEmployees() {
        Query query = …