使用Spring数据,JPA,hibernate和mySQL无法找到在mySQL数据库中插入数据的问题。它在数据库中插入两次数据。
root-context.xml文件是:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.8.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd">
<!-- Root Context: defines shared resources visible to all other web components -->
<context:component-scan base-package="com.project.db">
<context:exclude-filter type="annotation"
expression="org.springframework.stereotype.Controller" />
</context:component-scan>
<jdbc:embedded-database type="HSQL" id="dataSource"/>
<!-- <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost/jpa"/>
<property name="username" value="root"/>
<property name="password" value=""/>
</bean> -->
<!-- <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true"/>
<property name="generateDdl" value="true"/>
<property name="database" value="MYSQL"/>
</bean> -->
<bean class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
id="entityManagerFactory">
<property name="packagesToScan" value="com.project.db.entity"></property>
<property name="dataSource" ref="dataSource"></property>
<!-- <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/> -->
<property name="jpaProperties">
<props>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">create</prop>
</props>
</property>
<property name="persistenceProvider">
<bean class="org.hibernate.jpa.HibernatePersistenceProvider"/>
</property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
<bean class="org.springframework.orm.jpa.JpaTransactionManager"
id="transactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
<jpa:repositories base-package="com.project.db.repository"/>
</beans>
servlet-context.xml文件是:
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Enables the Spring MVC @Controller programming model -->
<annotation-driven />
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<context:component-scan base-package="com.project.db" />
</beans:beans>
我的@Entity课程是:
@Entity
public class User {
@Id
@GeneratedValue
private Integer id ;
private String name ;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
JPA存储库是:
import org.springframework.data.jpa.repository.JpaRepository;
import com.project.entity.User;
public interface UserRepository extends JpaRepository<User, Integer> {
}
最后,@ Service类是:
import javax.annotation.PostConstruct;
import javax.transaction.Transactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.project.entity.User;
import com.project.repository.UserRepository;
@Transactional
@Service
public class InitDbService {
@Autowired
private UserRepository userRepository;
@PostConstruct
public void init() {
User user = new User();
user.setName("Ali");
userRepository.save(user);
}
}
以上代码无错误/异常;还创建了数据库/表,但是当我在mySQL数据库中看到数据时,数据被插入到Entity / table中两次。 项目位于github。
控制台输出为:
INFO: Spring WebApplicationInitializers detected on classpath: [com.project.db.WebAppInitializer@1867584]
Sep 2, 2015 12:50:17 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring root WebApplicationContext
INFO : org.springframework.web.context.ContextLoader - Root WebApplicationContext: initialization started
INFO : org.springframework.web.context.support.XmlWebApplicationContext - Refreshing Root WebApplicationContext: startup date [Wed Sep 02 12:50:17 PKT 2015]; root of context hierarchy
INFO : org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from ServletContext resource [/WEB-INF/spring/root-context.xml]
INFO : org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor - JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
Hibernate: drop table if exists users
Hibernate: create table users (id integer not null auto_increment, name varchar(255), primary key (id))
Hibernate: insert into users (name) values (?) // first time inserting here and
INFO : org.springframework.web.context.ContextLoader - Root WebApplicationContext: initialization completed in 5633 ms
Sep 2, 2015 12:50:23 PM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'springDispatcher'
INFO : org.springframework.web.servlet.DispatcherServlet - FrameworkServlet 'springDispatcher': initialization started
INFO : org.springframework.web.context.support.XmlWebApplicationContext - Refreshing WebApplicationContext for namespace 'springDispatcher-servlet': startup date [Wed Sep 02 12:50:23 PKT 2015]; parent: Root WebApplicationContext
INFO : org.springframework.beans.factory.xml.XmlBeanDefinitionReader - Loading XML bean definitions from ServletContext resource [/WEB-INF/spring/appServlet/servlet-context.xml]
INFO : org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor - JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
INFO : org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping - Mapped "{[/],methods=[GET],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public java.lang.String com.project.db.HomeController.home(java.util.Locale,org.springframework.ui.Model)
INFO : org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter - Looking for @ControllerAdvice: WebApplicationContext for namespace 'springDispatcher-servlet': startup date [Wed Sep 02 12:50:23 PKT 2015]; parent: Root WebApplicationContext
INFO : org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter - Looking for @ControllerAdvice: WebApplicationContext for namespace 'springDispatcher-servlet': startup date [Wed Sep 02 12:50:23 PKT 2015]; parent: Root WebApplicationContext
INFO : org.springframework.web.servlet.handler.SimpleUrlHandlerMapping - Mapped URL path [/resources/**] onto handler 'org.springframework.web.servlet.resource.ResourceHttpRequestHandler#0'
Hibernate: insert into users (name) values (?) // Second time inserting here
INFO : org.springframework.web.servlet.DispatcherServlet - FrameworkServlet 'springDispatcher': initialization completed in 1483 ms
Sep 2, 2015 12:50:25 PM org.apache.catalina.core.StandardContext reload
INFO: Reloading Context with name [/db] is completed
答案 0 :(得分:1)
因为我看到你正在使用Spring MVC,所以抓住机会。
使用Spring MVC,您有一个定义控制器的servlet-context和一个用于其他bean的applicationContext。可能是你正在扫描servlet-context中控制器以外的bean,这反过来会给你两个InitDbService
的bean,它们都运行@ PostConstruct方法,插入到数据库中。
这可以通过定义组件扫描来解决:
servlet-context(仅在将控制器和控制器放在单独的包中之后):
<context:component-scan base-package="com.my.project.controller" />
的applicationContext:
<context:component-scan base-package="com.my.project">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
答案 1 :(得分:1)
您必须启用DEBUG日志记录来检查您的初始化bean是否未创建两次,正如Tobb在您在两个上下文中可能创建bean之前提到的那样。日志清楚地表明第一次插入是在根上下文初始化期间执行的(这是正确的),第二次是在servlet上下文初始化期间执行(这是错误的)
我找到了解决问题的方法:您必须在没有默认过滤器的情况下添加commponent扫描到根上下文
<context:component-scan base-package="com.project.db" />
和servlet-context是
{{1}}
我已经测试了您的项目,并且通过此更改正常运行。