使用SpringFramework时EntityManager始终为NULL [英] EntityManager is always NULL using SpringFramework
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问题描述
早上好，
我目前正在从事Maven + Spring + Hibernate项目。实际上，这只是一个测试项目，只是为了熟悉Spring与Hibernate（+ Maven）的工作方式。我已经设置并准备了必要的依赖项。例如，Spring的 appcontext.xml ，Hibernate的 persistence.xml ，JPA / Persistence的实体和DAO对象/ Hibernate。
I've been currently working on a Maven + Spring + Hibernate project. Actually, this is just a test project just to get familiar on how Spring works with Hibernate (+Maven). I've already setup and prepare the necessary dependencies. i.e. the appcontext.xml for Spring, the persistence.xml for Hibernate, the entity and DAO objects for JPA/Persistence/Hibernate.
在调试过程中，观察到 EntityManager 始终为 null 。我不知道是什么原因造成的，因为我完成了以下操作：
During debug, it's observed that the EntityManager is always null. I don't know what's causing this because I've done the ff:
- 在控制器上自动接线
- 在我的
applicationContext.xml - 中将其声明为Bean，将我的DAO对象注释为
@存储库 - 定义了
entityManagerFactory，transactionManager和vendorAdapter作为我的applicationContext.xml
- Autowire it on my controller
- Declared it as a bean on my
applicationContext.xml - Annotate my DAO object as
@Repository - Defined
entityManagerFactory,transactionManagerandvendorAdapteras beans on myapplicationContext.xml
上的bean
我整天都在调试并尝试解决方法。不幸的是，我还没有解决这个问题。希望有人能对此问题有所启发。
I've been debugging and trying workarounds all day. Unfortunately, I haven't resolve this yet. Hope someone can shed some light on this issue.
以下是我项目的代码和配置：
Below are the codes and configurations of my project:
<-persistence.xml --->
<--- 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_1_0.xsd"
version="1.0">
<persistence-unit name="msh" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.msh.TblFileinfo</class>
</persistence-unit>
</persistence>
< --- applicationContext.xml --->
<--- applicationContext.xml --->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:lang="http://www.springframework.org/schema/lang"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/lang
http://www.springframework.org/schema/lang/spring-lang-3.0.xsd
http://www.springframework.org/schema/security">
<!-- need to create database.properties file -->
<context:property-placeholder location="classpath:database.properties"/>
<context:component-scan base-package="com.msh"/>
<!-- tell Spring that it should act on any @PersistenceContext and @Transactional annotations found in bean classes -->
<!-- <tx:annotation-driven/> -->
<tx:annotation-driven transaction-manager="transactionManager"/>
<bean class="com.msh.TblFileinfoHome" />
<bean class="com.msh.TblFileinfo" />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
<bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<!-- <property name="databasePlatform" value="${platform}" /> -->
<property name="showSql" value="${database.showSql}" />
<property name="generateDdl" value="${database.generateDdl}" />
</bean>
<bean id="entityManagerFactory" class="org.org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="msh" />
<property name="dataSource" ref="dataSource" />
<!-- <property name="loadTimeWeaver" class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver" /> -->
<property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="${database.driverClassName}" />
<property name="url" value="${database.url}" />
<property name="username" value="${database.username}" />
<property name="password" value="${database.password}" />
</bean>
</beans>
<-主Java代码--->
<--- Main java code --->
package com.msh;
public class MavenSpringHibernate {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Sample s = new Sample();
s.persist();
}
}
<-DAO --->
<--- DAO --->
package com.msh;
import javax.ejb.Stateless;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityManager;
import javax.persistence.Persistence;
import javax.persistence.PersistenceUnit;
import javax.persistence.PersistenceContext;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Home object for domain model class TblFileinfo.
* @see com.trendmicro.grid.mshPackage.TblFileinfo
* @author Hibernate Tools
*/
/**
@Stateless
@Repository
@Transactional
*/
@Repository
public class TblFileinfoHome {
private static final Log log = LogFactory.getLog(TblFileinfoHome.class);
@PersistenceContext(unitName="msh")
private EntityManager entityManager;
@Transactional
public void persist(TblFileinfo transientInstance) {
log.debug("persisting TblFileinfo instance");
try {
entityManager.persist(transientInstance);
log.debug("persist successful");
}
catch (RuntimeException re) {
log.error("persist failed", re);
throw re;
}
}
@Transactional
public void remove(TblFileinfo persistentInstance) {
log.debug("removing TblFileinfo instance");
try {
entityManager.remove(persistentInstance);
log.debug("remove successful");
}
catch (RuntimeException re) {
log.error("remove failed", re);
throw re;
}
}
@Transactional
public TblFileinfo merge(TblFileinfo detachedInstance) {
log.debug("merging TblFileinfo instance");
try {
TblFileinfo result = entityManager.merge(detachedInstance);
log.debug("merge successful");
return result;
}
catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
}
@Transactional
public TblFileinfo findById( Long id) {
log.debug("getting TblFileinfo instance with id: " + id);
try {
TblFileinfo instance = entityManager.find(TblFileinfo.class, id);
log.debug("get successful");
return instance;
}
catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
}
}
-实体- -
package com.msh;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.Table;
/**
* TblFileinfo generated by hbm2java
*/
@Entity
@Table(name="tbl_fileinfo"
,catalog="behavior"
)
public class TblFileinfo implements java.io.Serializable {
private Long fileId;
private String filename;
private String filetype;
public TblFileinfo() {
}
public TblFileinfo(String filename, String filetype) {
this.filename = filename;
this.filetype = filetype;
}
@Id @GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="file_id", unique=true, nullable=false)
public Long getFileId() {
return this.fileId;
}
public void setFileId(Long fileId) {
this.fileId = fileId;
}
@Column(name="filename", length=200)
public String getFilename() {
return this.filename;
}
public void setFilename(String filename) {
this.filename = filename;
}
@Column(name="filetype", length=50)
public String getFiletype() {
return this.filetype;
}
public void setFiletype(String filetype) {
this.filetype = filetype;
}
}
<-样本类控制器- >
<--- Sample class controller --->
package com.msh;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import com.trendmicro.grid.msh.TblFileinfo;
import com.trendmicro.grid.msh.TblFileinfoHome;
@Transactional
public class Sample {
@Autowired
private TblFileinfo tinfo;
private TblFileinfoHome tinfoh;
public Sample()
{
tinfo = new TblFileinfo("c:/jayson/murillo/pryde.exe", "uv_win32");
tinfoh = new TblFileinfoHome();
}
public void persist()
{
tinfoh.persist(tinfo);
}
}
再次，希望有人能对此提供反馈。
Again, hope someone can provide feedback on this. Thanks in advance!
推荐答案
您甚至没有开始Spring！
You aren't even starting Spring!
Sample s = new Sample();
示例是Spring bean。您必须首先启动应用程序上下文并从那里获取bean。参见@nico_ekito的答案：
Sample is a Spring bean. You must first start the application context and fetch the bean from there. See @nico_ekito's answer:
public static void main(String[] args) {
ApplicationContext context =
new ClassPathXmlApplicationContext("classpath:/applicationContext.xml");
Sample s = context.getBean(Sample.class);
s.persist();
}
一旦启动上下文（可能会导致某些错误），请更正以下内容：
Once you start the context (which will probably result with some errors), correct the following:
-
删除此内容：
Remove this:
tinfoh = new TblFileinfoHome();
用以下内容注释字段：
@Autowired
private TblFileinfoHome tinfoh;
您不应该自动装配实体类：
you should not be autowiring entity class:
@Autowired //remove this annotation
private TblFileinfo tinfo;
这篇关于使用SpringFramework时EntityManager始终为NULL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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