Spring + JPA + Hibernate
Solution 1
I think you're missing the configuration to tell spring to search for the annotations (add the following anywhere between the <beans>
element:
<context:annotation-config />
And maybe you also need to add the following specifying the package where you have the DAO. But I don't think this is required.
<context:component-scan base-package="your.package" />
Solution 2
this is working piece of code:
Spring.xml:
<?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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="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
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
<context:annotation-config />
<context:component-scan base-package="com.package.dao" />
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
<property name="persistenceUnitName" value="fcmsServer" />
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
</beans>
Dao bean:
@Repository
public class UserDaoBean implements UserDao {
@PersistenceContext
protected EntityManager em;
}
Persistence.xml:
<?xml version="1.0" encoding="UTF-8" ?>
<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="fcmsServer" transaction-type="RESOURCE_LOCAL">
<class>com.package.entity.</class>
<properties>
<property name="javax.persistence.jdbc.url"
value="jdbc:mysql://localhost:3306/db_name"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="admin"/>
<property name="javax.persistence.jdbc.password" value="admin"/>
</properties>
</persistence-unit>
</persistence>
Mikhail S
Updated on April 12, 2020Comments
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Mikhail S about 4 years
I am newbie in Spring. I am trying to setup simple web application with Spring 3.1.3 and JPA 2.0 I have added all necessary libs to the WEB-INF/lib. There is no errors during the startup but entityManager in my DaoImpl file is null. So, this is my configuration:
persistance.xml
<?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" 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"> <persistence-unit name="fcmsServer" transaction-type="RESOURCE_LOCAL"> </persistence-unit> </persistence>
fcms-servlet.xml
<?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:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="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 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd"> <!-- the application context definition for the fcmsServer DispatcherServlet --> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="persistenceUnitName" value="fcmsServer" /> <property name="dataSource" ref="dataSource" /> <property name="jpaDialect"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" /> </property> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <property name="showSql" value="true" /> <property name="generateDdl" value="true" /> <property name="databasePlatform" value="org.hibernate.dialect.H2Dialect" /> </bean> </property> <property name="persistenceUnitManager"> <bean class="org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager"> <property name="defaultDataSource" ref="dataSource" /> </bean> </property> </bean> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="org.h2.Driver" /> <property name="url" value="jdbc:h2:tcp://localhost/~/fcms" /> <property name="username" value="sa" /> <property name="password" value="sa" /> </bean> <tx:annotation-driven transaction-manager="transactionManager" /> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> <property name="dataSource" ref="dataSource" /> </bean> <bean id="persistenceAnnotation" class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" /> <bean id="userDao" class="fcms.data.user.UserDAOImpl"> </bean> <bean name="/user.htm" class="fcms.controller.UserController"> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean>
DaoImpl class:
@Repository public class UserDAOImpl implements UserDAO { @PersistenceContext(unitName = "fcmsServer") private EntityManager entityManager; public void setEntityManager(EntityManager entityManager) { this.entityManager = entityManager; } @Override public User getUserById(long id) { return entityManager.find(User.class,id); } @Override public void addUser(User u) { entityManager.persist(u); } }
User class
@Entity @Table(name = "User") public class User implements Serializable { @Id @GeneratedValue private long id; @Column(name = "lastName", nullable = false) private String lastName; @Column(name = "firstName", nullable = false) private String firstName; @Column(name = "birthDate", nullable = true) private Date birthDate; private static final long serialVersionUID = 1L;
}
So when I try to call addUser() in UserController, I have NullPointerException during persist.
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Mikhail S about 11 yearsUnfortunatelly, this solution does not fix the problem. entityManager is still equeal to null.
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Ferda-Ozdemir-Sonmez over 7 yearsHi, I am also defining an entitymanagerfactory like your ut I am not sure what should I have to give to the persistence-unit name="fcmsServer". What does it refer to?
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bvyas almost 7 years@Ferda-Ozdemir-Sonmez : persistence-unit name is just for unique identiier of your entityManagerFactory. This is helpful when any application is configure more than one database/dataSource. You can give any name.