实体不存在-spring+hibernate+ JPA
我正在使用Spring + Hibernate+JPA，但遇到无法将实体持久保存到数据库的情况。我已经建立了一个带有@Transactional注释的服务类。它使用包含注入的EntityManager的DAO。当我在服务对象上调用函数时，我看到DAO正在进行大量的选择读取，但是由于我的DAO发出的合并和删除操作，没有更新/删除。当然，我的设置有问题，但是我看不到它。
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="pu">
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.InformixDialect" />
<property name="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider" />
<property name="hibernate.showsql" value="true" />
<property name="hibernate.cache.use_second_level_cache"
value="false" />
</properties>
</persistence-unit>
config.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:security="http://www.springframework.org/schema/security"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
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/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/security
http://www.springframework.org/schema/security/spring-security-3.0.3.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://localhost:5432/testdb" />
<property name="username" value="username" />
<property name="password" value="password" />
</bean>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="pu" />
<property name="dataSource" ref="dataSource" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true" />
<property name="databasePlatform" value="org.hibernate.dialect.PostgreSQLDialect" />
</bean>
</property>
<property name="loadTimeWeaver">
<bean
class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="entityManagerFactory" />
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>
<context:annotation-config/>
</beans>
AccountService.java
@Service("accountService")@Transactional(propagation=Propagation.REQUIRED)
public class AccountService {
private static final Logger log = Logger.getLogger(AccountService.class);
@Autowired
private UserDAO userDAO;
public void activateUser(String username, String activationCode) {
PendingActivation pendingActivation = userDAO.getPendingActivation(
username, activationCode);
Client client = pendingActivation.getClient();
if (!userDAO.removePendingActivation(pendingActivation)) {
log.warn("Unable to remove pending activation");
}
if (!userDAO.enableUser(client)) {
log.error("Unable to enable client");
return;
}
return;
}
}
UserDAOImpl.java
@Repository("userDAO")public class UserDAOImpl implements UserDAO, Serializable {
private static final long serialVersionUID = 1L;
private static Logger log = Logger.getLogger(UserDAOImpl.class);
@PersistenceContext
EntityManager em;
@Override
public PendingActivation getPendingActivation(String username, String activationCode) {
Query q = em.createNamedQuery("getActivationCode")
.setParameter("activationCode", activationCode);
PendingActivation pendingActivation = null;
try {
pendingActivation = (PendingActivation)q.getSingleResult();
return pendingActivation;
}
catch (Exception e) {
log.warn("Could not retrieve activation code " + activationCode + " for user " + username, e);
return null;
}
}
@Override
public boolean enableUser(Client client) {
try {
client.setEnabled(true);
client = em.merge(client); // this never generates an update
}
catch(Exception e) {
log.error("Unable to enable client: " + client.getUsername(), e);
return false;
}
return true;
}
@Override
public boolean removePendingActivation(PendingActivation pendingActivation) {
try {
pendingActivation = (PendingActivation)em.getReference(PendingActivation.class, pendingActivation.getPendingActivationId());
em.remove(pendingActivation); // this never generates a delete
}
catch(Exception e) {
log.warn("Unable to remove activation: " + pendingActivation.getActivationCode(), e);
return false;
}
return true;
}
}
AccountActivationController.java
@Controllerpublic class AccountActivationController {
@Autowired
@Qualifier("accountService")
AccountService accountService;
@RequestMapping("activate.do")
public String doActivate(
@RequestParam("activationCode") String activationCode,
@RequestParam("username") String username,
ModelMap model) {
UnitCriteria unitCriteria = accountService.activateUser(username, activationCode);
if (unitCriteria == null) {
return "account/activationError";
}
model.addAttribute("fromActivation", true);
return "forward:search.do?" + unitCriteria.toUrlParams(true);
}
}
回答：
好的，我知道了问题所在。我花了很长时间才弄清楚这一点，与我的数据库配置无关，所以我想为遇到类似问题的人们提供帮助。
Spring文档指出以下内容：
<tx:annotation-driven/>仅在定义的相同应用程序上下文中在bean上查找@Transactional。这意味着，如果<tx:annotation- driven/>为DispatcherServlet 放入 WebApplicationContext，则仅在控制器而不是服务中检查@Transactional bean。有关更多信息，请参见第15.2节“ DispatcherServlet”。
我的原始帖子中没有发布的是我的Servlet定义，其中包含以下几行配置代码：
myServlet.xml
<context:annotation-config /> <context:component-scan base-package="com.myDomain.*" />
这会将所有带注释的Bean（包括控制器，服务和存储库）带入Servlet上下文而不是应用程序上下文。问题就在这里。当Spring寻找用@Transactional注释的bean（由于<tx:annotation-
driven/>config.xml文件中存在）时，它将在应用程序上下文中寻找它们。而且，根据我在上一个线程中发布的配置，没有将任何bean加载到我的应用程序上下文中……它们都在servlet上下文中。因此，当我的servlet调用以@Service＆@ 注释的 它 。因此，没有交易。诀窍（而是正确的方法）是通过以下方式更改我的配置文件：
myServlet.xml
<context:annotation-config /> <context:component-scan base-package="com.myDomain.servlets" />
config.xml
<context:annotation-config /> <context:component-scan base-package="com.myDomain.dao" />
<context:component-scan base-package="com.myDomain.services" />
此配置确保所有Controller都存在于servlet上下文中，而Transactional Services和Repository存在于 _它们所属_的应用程序上下文中。最后，经过许多不眠之夜，我的数据库写操作仍在继续。
以上是 实体不存在-spring+hibernate+ JPA 的全部内容， 来源链接： utcz.com/qa/397312.html
