Question

我是spring-data的新手，我想尝试使用spring数据而不使用@autowired而不是存储库。我只想通过xml直接注入存储库，因为我无法从xml中获取我的实现类中的存储库实例，使用基于xml的配置的原因是我以前的服务层和控制器不支持任何注释功能所以我必须使用spring数据操作dao层这是我的xml配置

      <?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: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-3.1.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-1.2.xsd http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-2.5.xsd">


            <context:component-scan base-package="com.nousinfo.tutorial" />
            <!-- Database -->
            <bean id="datasource"
                class="org.springframework.jdbc.datasource.DriverManagerDataSource">
                <property name="driverClassName" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://192.168.25.30:3306/employee" />
                <property name="username" value="***" />
                <property name="password" value="*****" />
            </bean>

            <!-- Entity Manager -->
            <bean id="entityManagerFactory"
                class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
                <property name="dataSource" ref="datasource" />
                <property name="persistenceUnitName" value="EmployeeApp" />
            </bean>

            <!-- Transaction Manager -->
            <beanid="transactionManager"                                                                               class="org.springframework.orm.jpa.JpaTransactionManager">
                <property name="entityManagerFactory" ref="entityManagerFactory" />
            </bean>

    <!--- here i having problem on injecting the bean of employeeRepositories---->
            <bean id="employeeDaoImpl" class="com.nousinfo.tutorial.repository.impl.EmployeeDAOImpl">
                <property name="employeeRepository" ref="employeeRepository" />
            </bean>
   <bean id="employeeRepositories" class="com.nousinfo.tutorial.dao.EmployeeRepositories"/>


            <!-- Jpa Repositories -->
            <jpa:repositories base-package="com.nousinfo.tutorial.dao"></jpa:repositories>

  </beans>

这是我的persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
version="1.0">
<persistence-unit name="EmployeeApp" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>com.nousinfo.tutorial.model.Department</class>
    <properties>
        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
        <property name="hibernate.hbm2ddl.auto" value="update" />
        <property name="hibernate.show_sql" value="true" />
    </properties>
</persistence-unit>

这是我的员工存储库

public interface EmployeeRepositories extends JpaRepository<Employee, Long> {
    public List<Employee> findByFirstName(String name);

    @Query("FROM Employee emp WHERE emp.firstName = :firstname or emp.lastName = :lastname")
    List<Employee> getEmployeesByName(@Param("lastname") String lastname,
            @Param("firstname") String firstname);

    List<Employee> findByLastNameOrderByFirstNameAsc(String lastname);

    List<Employee> findByLastNameOrderByFirstNameDesc(String lastname);

    List<Employee> findByDepartmentId(String departmentId);

}

这是我的实施

public class EmployeeDAOImpl {

EmployeeRepositories employeeRepositories ;

public void setEmployeeRepositories (EmployeeRepositories employeeRepositories ) {
    this.employeeRepositories = employeeRepositories ;
}

public List<Employee> getAllEmployees() {
    return employeeRepositories.findAll();
}

这种方式我称之为测试方法

 ApplicationContext applicationContext=new ClassPathXmlApplicationContext("MyBean.xml");
        EmployeeDAOImpl daOImpl=(EmployeeDAOImpl)applicationContext.getBean("employeeDaoImpl");
daOImpl.getAllEmployees();

因为错误的映射而出现异常，所以请提供正确的映射，我将感谢你

这是我的例外

    Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeDaoImpl' defined in class path resource [mybeans.xml]: Cannot resolve reference to bean 'employeeRepositories' while setting bean property 'employeeRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepositories' defined in class path resource [mybeans.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.nousinfo.tutorial.dao.EmployeeRepository]: Specified class is an interface
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1317)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1076)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:574)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at com.nousinfo.tutorial.common.basemodel.MainTest.main(MainTest.java:13)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepositories' defined in class path resource [mybeans.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.nousinfo.tutorial.dao.EmployeeRepository]: Specified class is an interface
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:955)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:901)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:485)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322)
    ... 15 more
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.nousinfo.tutorial.dao.EmployeeRepository]: Specified class is an interface
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:52)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:948)
    ... 23 more

Answer 1

删除

<bean id="employeeRepositories" class="com.nousinfo.tutorial.repository.EmployeeRepositories"/>

并使用：

        <bean id="employeeDaoImpl" class="com.nousinfo.tutorial.repository.impl.EmployeeDAOImpl">
            <property name="employeeDAO" ref="employeeRepositories " />
        </bean>

Answer 2

问题在于以下陈述

<bean id="employeeRepositories" class="com.nousinfo.tutorial.dao.EmployeeRepositories"/>

EmployeeRepositories是一个接口。您无法为接口创建bean。

您必须在bean

中提供实现类

<bean id="employeeRepositories" class="<Implementation class>"/>

如果您使用jpa:repositories标记，请检查您是否在EmployeeRepository实现类中提供了@Repository标记，如

@Repository
class EmployeeReporsitoriesImpl implements EmployeeReporsitories

在实现类中注入存储库而不使用xml在spring数据中使用@autowired

2 个答案: