spring配置entitymangerfactory

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="packagesToScan" value="com"/>
    <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.MySQL5InnoDBDialect"/>
        </bean>
    </property>
</bean>

报错：

 Bean property 'packagesToScan' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?

解决：