Question

我有一个带有以下设置的网络项目：

Wildfly 9.0
JSF 2.2
EJB 3.2
Hibernate 4.2.21

我想从ManagedBean到注入的EJB进行简单的方法调用。 Hibernate配置为EJB的EntityManager。

观点：

<?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">
<h:html xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:p="http://primefaces.org/ui"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
    xmlns:o="http://omnifaces.org/ui"
    xmlns:of="http://omnifaces.org/functions">
<h:head>

</h:head>
<h:body>

    <h:form>
        <h:inputText value="#{courseController.course.room}"/>

        <h:commandButton 
            value="save" action="#{courseController.addCourse}"/>    
    </h:form>

</h:body>
</h:html>

视图的ManagedBean：

import java.io.Serializable;

import javax.ejb.EJB;
import javax.faces.bean.ViewScoped;
import javax.inject.Named;

import de.uulm.vs.increase.teachinput.ejb.CourseEJB;
import de.uulm.vs.increase.teachinput.model.Course;

@Named(value="courseController")
@ViewScoped
public class CourseController implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @EJB
    private CourseEJB courseEJB;

    private Course course = new Course();

    public String addCourse()
    {
        courseEJB.addCourse(course);
        return "course.xhtml";
    }

    public Course getCourse()
    {
        return course;
    }

    public void setCourse(Course course) {
        this.course = course;
    }

}

EJB：

import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import de.uulm.vs.increase.teachinput.model.Course;

@Stateless(mappedName = "courseEJB")
@LocalBean
public class CourseEJB implements CourseEJBLocal {

    @PersistenceContext(unitName = "teach-input")
    EntityManager em;

    public CourseEJB() {

    }

    public Course addCourse(Course c)
    {
        em.persist(c);
        return c;
    }

}

EJB接口：

import javax.ejb.Local;

import de.uulm.vs.increase.teachinput.model.Course;

@Local
public interface CourseEJBLocal {

    public Course addCourse(Course c);
}

的persistence.xml：

<persistence 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"
    version="2.0">

    <persistence-unit name="teach-input" transaction-type="JTA">
        <description>
            Persistence unit for the teach-input project.
        </description>

        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <properties>

            <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/test"></property>
            <property name="hibernate.connection.username" value="user"></property>
            <property name="hibernate.connection.password" value="pw"></property>
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"></property>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"></property>
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="create" />

        </properties>

    </persistence-unit>

</persistence>

beans.xml中：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://xmlns.jcp.org/xml/ns/javaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee 
                           http://xmlns.jcp.org/xml/ns/javaee/beans_1_1.xsd"
       version="1.1" bean-discovery-mode="all">
</beans>

我通过maven构建一个war文件

的pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>groupid</groupId>
    <artifactId>artifactid</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>name</name>

    <properties>
        <hibernate.version>4.2.21.Final</hibernate.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <!-- MySQL -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.37</version>
        </dependency>
        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-envers</artifactId>
            <version>${hibernate.version}</version>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>

        <!-- EJB -->
        <dependency>
            <groupId>javax.ejb</groupId>
            <artifactId>javax.ejb-api</artifactId>
            <version>3.2</version>
            <scope>provided</scope>
        </dependency>

        <!-- JSF -->

        <dependency>
            <groupId>javax.faces</groupId>
            <artifactId>javax.faces-api</artifactId>
            <version>2.2</version>
            <scope>provided</scope>
        </dependency>

        <!-- WELD -->
        <dependency>
            <groupId>org.jboss.weld.servlet</groupId>
            <artifactId>weld-servlet</artifactId>
            <version>2.3.2.Final</version>
            <scope>provided</scope>
        </dependency>

    </dependencies>

    <build>
        <finalName>finalname</finalName>
        <defaultGoal>install</defaultGoal>
        <pluginManagement>
            <plugins>
                <!-- WildFly plugin to deploy the application -->
                <plugin>
                    <groupId>org.wildfly.plugins</groupId>
                    <artifactId>wildfly-maven-plugin</artifactId>
                    <version>1.0.2.Final</version>
                    <configuration>
                        <filename>${project.build.finalName}.war</filename>
                        <hostname>127.0.0.1</hostname>
                        <port>9990</port>
                        <username>user</username>
                        <password>password</password>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <configuration>
                        <source>1.7</source>
                        <target>1.7</target>
                        <encoding>UTF-8</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-eclipse-plugin</artifactId>
                    <configuration>
                        <downloadSources>true</downloadSources>
                        <downloadJavadocs>true</downloadJavadocs>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

</project>

服务器正在正确部署。通过Web界面调用addCourse()方法时，将显示以下异常：

WFLYEJB0034：对于方法publicEJB，EJB调用失败方法public course addCourse（Course）：javax.ejb.EJBException：java.lang.NullPointerException

因此，注入EJB似乎出现了问题。我在WildFly文档中查找了它，但缺少EJB配置章节。

提前感谢您的帮助。

Answer 1

从EJB实现中删除@LocalBean注释
删除mappedName属性 - 您是否需要此示例？
使用界面进行注入，例如@EJB CourseEJBLocal

希望有所帮助

Answer 2

您正在将CDI- @ Named与JSF-Scopes混合使用：

使用

import javax.inject.Named;
import javax.enterprise.context.ConversationScoped;


@Named
@ConversationScoped
public class CourseController implements Serializable {

或

import javax.faces.bean.ViewScoped;
import javax.faces.bean.ManagedBean;

@ManagedBean
@ViewScoped
public class CourseController implements Serializable {

Wildfly：EJB调用失败 - NullPointerException

2 个答案: