spring4+hibernate4配置过程中遇到的问题

1.在web.xml中配置spring（包括springMVC）

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>
classpath:applicationContext.xml
</param-value>
</context-param>

<!-- spring framework -->
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>

<filter>
<filter-name>openSessionInViewFilter</filter-name>
<filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
<init-param>
<param-name>singleSession</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>openSessionInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- Spring MVC -->
<servlet>
<servlet-name>springMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:/spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

<filter>
<filter-name>EncodingFilter</filter-name>
<filter-class>
org.springframework.web.filter.CharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>EncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- Session 超时配置，单位是分钟 -->
<session-config>
<session-timeout>20</session-timeout>
</session-config>

<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>2.配置applicationContext.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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">

<!-- 让spring关注配置文件 -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>classpath:jdbc.properties</value>
</property>
</bean>

<!-- 配置spring关注注解Annotation -->
<context:annotation-config/>
<!-- 使用Annotation自动注册Bean -->
<context:component-scan base-package="com.watson.*"/>

<!-- 配置c3p0数据源 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass">
<value>${jdbc.driverClassName}</value>
</property>
<property name="jdbcUrl">
<value>${jdbc.url}</value>
</property>
<property name="user">
<value>${jdbc.username}</value>
</property>
<property name="password">
<value>${jdbc.password}</value>
</property>
<property name="initialPoolSize"><value>1</value></property>
<property name="minPoolSize"><value>1</value></property>
<property name="maxPoolSize"><value>20</value></property>
<property name="acquireIncrement"><value>2</value></property>
<property name="maxIdleTime"><value>10</value></property>
<property name="maxStatements"><value>0</value></property>
</bean>

<!-- 配置hibernate4的sessionFactory -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean" >
<property name="dataSource"><ref bean="dataSource"/></property>
<!-- 这一属性非常重要，只有被该属性扫描到的entity才会被当做hibernate的entity来使用，否则会报org.hibernate.MappingException: Unknown entity -->
<property name="packagesToScan" value="com.watson"/>
<property name="hibernateProperties">
<props>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.format_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.cache.use_second_level_cache">false</prop>
<prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.Oracle9iDialect</prop>
</props>
</property>
</bean>

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
abstract="false" lazy-init="false" autowire="default"
dependency-check="default">
<property name="dataSource">
<ref bean="dataSource" />
</property>
</bean>

<!-- 定义事务 -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<!-- 配置 Annotation 驱动，扫描@Transactional注解的类定义事务 -->
<tx:annotation-driven transaction-manager="transactionManager"/>

<!-- 定义事务的传播属性 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="save*" propagation="REQUIRED"/>
<tx:method name="set*" propagation="REQUIRED"/>
<tx:method name="del*" propagation="REQUIRED"/>
<tx:method name="update*" propagation="REQUIRED"/>

<tx:method name="get*" read-only="true" propagation="NOT_SUPPORTED"/>
<tx:method name="find*" read-only="true" propagation="NOT_SUPPORTED"/>
<tx:method name="query*" read-only="true" propagation="NOT_SUPPORTED"/>
<tx:method name="select*" read-only="true" propagation="NOT_SUPPORTED"/>

<tx:method name="*" rollback-for="Exception"/>
</tx:attributes>
</tx:advice>
<aop:config proxy-target-class="true">
<aop:pointcut id="txNeed" expression="execution(* com.watson.app.service..*.*(..))"/>
<aop:advisor pointcut-ref="txNeed" advice-ref="txAdvice"/>
</aop:config>
</beans>

3.配置spring-mvc.xml文件
<?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:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
<!-- 默认的注解映射的支持，激活@Controller模式 -->
<mvc:annotation-driven />

<context:component-scan base-package="com.watson.*" >
<context:include-filter type="annotation"
expression="org.springframework.stereotype.Controller"/>
</context:component-scan>

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix"><value>/views/</value></property>
<property name="suffix"><value>.jsp</value></property>
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
</bean>
</beans>4.Spring4+Hibernate4中不再支持HibernaterTemplate，只能使用原生的session接口来操作。在Hibernate4中也有HibernaterTemplate，但是如果没有用getCurrentSession()开启一个session，那么hibernate会自己调用openSession()，但是同时调用setFlushMode(FlushMode.MANUAL)，导致操作模式变成只读(readonly)，所以在执行save,update,delete等操作时都会报不允许写操作的错误。如果非要使用HibernaterTemplate，那么必须先要用session.setFlushMode(FlushMode.AUTO)设置操作模式为自动。所以建议不要使用HibernaterTemplate，而是用原生的session接口操作数据库。
5.配置好所以配置文件后，按照注解的方式用@Entity注解entity类，结果一直报unkown entity的错误，原因如下：

首先注解的@Entity是在import javax.persistence.Entity;这个包下面，而不是hibernate的注解包里。

其次是必须在applicationContext.xml文件配置sessionFactory工厂Bean是必须加入一个属性

<property name="packagesToScan" value="com.watson"/>，加入这个属性之后工厂类才会去扫描com.watson包下面所有用@Entity注解的实体类。

6.报org.hibernate.AnnotationException: No identifier specified for entity错误，hibernate需要提供一个唯一标识ID，在实体类中可以用以下注解标识

@Id
@GeneratedValue(strategy=GenerationType.SEQUENCE)

@Column(name="EMPNO")

private Integer empno;

此处特别注意注解是标注在属性声明上，不能标注在setXXX方法上，否则也会报这个错误。

7.报java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config错误，加入以下包就可以了

<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.1.2</version>
</dependency>

<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>