一 开发环境
1、动态web工程
2、部分依赖
java代码: - hibernate-validator-4.2.0.Final.jar
- spring-framework-3.1.1.RELEASE-with-docs.zip
- proxool-0.9.1.jar
- log4j 1.2.16
- slf4j -1.6.1
- mysql-connector-java-5.1.10.jar
- hamcrest 1.3.0RC2
- ehcache 2.4.3
hibernate-release-4.1.0.Final.zip
hibernate-validator-4.2.0.Final.jar
spring-framework-3.1.1.RELEASE-with-docs.zip
proxool-0.9.1.jar
log4j 1.2.16
slf4j -1.6.1
mysql-connector-java-5.1.10.jar
hamcrest 1.3.0RC2
ehcache 2.4.3
3、为了方便学习,暂没有使用maven构建工程
二 工程主要包括内容
1、springMVC + spring3.1.1 + hibernate4.1.0集成
2、通用DAO层 和 Service层
3、二级缓存 Ehcache
4、REST风格的表现层
5、通用分页(两个版本)
6、数据库连接池采用proxool
7、spring集成测试
8、表现层的 java validator框架验证(采用hibernate-validator-4.2.0实现)
9、视图采用JSP,并进行组件化分离
三 TODO LIST 将本项目做成脚手架方便以后新项目查询
1、Service层进行AOP缓存(缓存使用Memcached实现)
2、单元测试(把常见的桩测试、伪实现、模拟对象演示一遍 区别集成测试)
3、监控功能
后台查询hibernate二级缓存 hit/miss率功能
后台查询当前服务器状态功能(如 线程信息、服务器相关信息)
4、spring RPC功能
5、spring集成 quartz 进行任务调度
6、spring集成 java mail进行邮件发送
7、DAO层将各种常用框架集成进来(方便查询)
8、把工作中经常用的东西 融合进去,作为脚手架,方便以后查询
四 集成重点及常见问题
1、spring-config.xml 配置文件:
1.1、该配置文件只加载除表现层之外的所有bean,因此需要如下配置:
java代码: - <context:component-scan base-package="cn.javass">
- <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
- </context:component-scan>
<context:component-scan base-package="cn.javass">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
通过exclude-filter 把所有 @Controller注解的表现层控制器组件排除
1.2、国际化消息文件配置
java代码: - <!-- 国际化的消息资源文件 -->
- <bean id="messageSource"class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
- <property name="basenames">
- <list>
- <!-- 在web环境中一定要定位到classpath 否则默认到当前web应用下找 -->
- <value>classpath:messages</value>
- </list>
- </property>
- <property name="defaultEncoding" value="UTF-8"/>
- <property name="cacheSeconds" value="60"/>
- </bean>
<!-- 国际化的消息资源文件 -->
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basenames">
<list>
<!-- 在web环境中一定要定位到classpath 否则默认到当前web应用下找 -->
<value>classpath:messages</value>
</list>
</property>
<property name="defaultEncoding" value="UTF-8"/>
<property name="cacheSeconds" value="60"/>
</bean>
此处basenames内一定是 classpath:messages ,如果你写出“messages”,将会到你的web应用的根下找 即你的messages.properties一定在 web应用/messages.propertis。
1.3、hibernate的sessionFactory配置 需要使用org.springframework.orm.hibernate4.LocalSessionFactoryBean,其他都是类似的,具体看源代码。
1.、<aop:aspectj-autoproxy expose-proxy="true"/> 实现@AspectJ注解的,默认使用AnnotationAwareAspectJAutoProxyCreator进行AOP代理,它是BeanPostProcessor的子类,在容器启动时Bean初始化开始和结束时调用进行AOP代理的创建,因此只对当容器启动时有效,使用时注意此处。
1.5、声明式容器管理事务
建议使用声明式容器管理事务,而不建议使用注解容器管理事务(虽然简单),但太分布式了,采用声明式容器管理事务一般只对service层进行处理。
java代码: - <tx:advice id="txAdvice" transaction-manager="txManager">
- <tx:attributes>
- <tx:method name="save*" propagation="REQUIRED" />
- <tx:method name="add*" propagation="REQUIRED" />
- <tx:method name="create*" propagation="REQUIRED" />
- <tx:method name="insert*" propagation="REQUIRED" />
- <tx:method name="update*" propagation="REQUIRED" />
- <tx:method name="merge*" propagation="REQUIRED" />
- <tx:method name="del*" propagation="REQUIRED" />
- <tx:method name="remove*" propagation="REQUIRED" />
- <tx:method name="put*" propagation="REQUIRED" />
- <tx:method name="use*" propagation="REQUIRED"/>
- <!--hibernate4必须配置为开启事务 否则 getCurrentSession()获取不到-->
- <tx:method name="get*" propagation="REQUIRED" read-only="true" />
- <tx:method name="count*" propagation="REQUIRED" read-only="true" />
- <tx:method name="find*" propagation="REQUIRED" read-only="true" />
- <tx:method name="list*" propagation="REQUIRED" read-only="true" />
- <tx:method name="*" read-only="true" />
- </tx:attributes>
- </tx:advice>
- <aop:config expose-proxy="true">
- <!-- 只对业务逻辑层实施事务 -->
- <aop:pointcut id="txPointcut" expression="execution(* cn.javass..service..*.*(..))" />
- <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/>
- </aop:config>
<tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="save*" propagation="REQUIRED" />
<tx:method name="add*" propagation="REQUIRED" />
<tx:method name="create*" propagation="REQUIRED" />
<tx:method name="insert*" propagation="REQUIRED" />
<tx:method name="update*" propagation="REQUIRED" />
<tx:method name="merge*" propagation="REQUIRED" />
<tx:method name="del*" propagation="REQUIRED" />
<tx:method name="remove*" propagation="REQUIRED" />
<tx:method name="put*" propagation="REQUIRED" />
<tx:method name="use*" propagation="REQUIRED"/>
<!--hibernate4必须配置为开启事务 否则 getCurrentSession()获取不到-->
<tx:method name="get*" propagation="REQUIRED" read-only="true" />
<tx:method name="count*" propagation="REQUIRED" read-only="true" />
<tx:method name="find*" propagation="REQUIRED" read-only="true" />
<tx:method name="list*" propagation="REQUIRED" read-only="true" />
<tx:method name="*" read-only="true" />
</tx:attributes>
</tx:advice>
<aop:config expose-proxy="true">
<!-- 只对业务逻辑层实施事务 -->
<aop:pointcut id="txPointcut" expression="execution(* cn.javass..service..*.*(..))" />
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPointcut"/>
</aop:config>
此处一定注意 使用 hibernate4,在不使用OpenSessionInView模式时,在使用getCurrentSession()时会有如下问题:
当有一个方法list 传播行为为Supports,当在另一个方法getPage()(无事务)调用list方法时会抛出org.hibernate.HibernateException: No Session found for current thread 异常。
这是因为getCurrentSession()在没有session的情况下不会自动创建一个,不知道这是不是Spring3.1实现的bug,欢迎大家讨论下。
因此最好的解决方案是使用REQUIRED的传播行为。请看最后的分析
二、spring-servlet.xml:
2.1、表现层配置文件,只应加装表现层Bean,否则可能引起问题。
java代码: - <!-- 开启controller注解支持 -->
- <!-- 注:如果base-package=cn.javass 则注解事务不起作用-->
- <context:component-scan base-package="cn.javass.demo.web.controller">
- <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
- </context:component-scan>
<!-- 开启controller注解支持 -->
<!-- 注:如果base-package=cn.javass 则注解事务不起作用-->
<context:component-scan base-package="cn.javass.demo.web.controller">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
此处只应该加载表现层组件,如果此处还加载dao层或service层的bean会将之前容器加载的替换掉,而且此处不会进行AOP织入,所以会造成AOP失效问题(如事务不起作用),再回头看我们的1.4讨论的。
2.2、<mvc:view-controller path="/" view-name="forward:/index"
/> 表示当访问主页时自动转发到index控制器。
2.3、静态资源映射
java代码: - <!-- 当在web.xml 中 DispatcherServlet使用 <url-pattern>/</url-pattern> 映射时,能映射静态资源 -->
- <mvc:default-servlet-handler/>
- <!-- 静态资源映射 -->
- <mvc:resources mapping="/images/**" location="/WEB-INF/images/" />
- <mvc:resources mapping="/css/**" location="/WEB-INF/css/" />
- <mvc:resources mapping="/js/**" location="/WEB-INF/js/" />
<!-- 当在web.xml 中 DispatcherServlet使用 <url-pattern>/</url-pattern> 映射时,能映射静态资源 -->
<mvc:default-servlet-handler/>
<!-- 静态资源映射 -->
<mvc:resources mapping="/images/**" location="/WEB-INF/images/" />
<mvc:resources mapping="/css/**" location="/WEB-INF/css/" />
<mvc:resources mapping="/js/**" location="/WEB-INF/js/" />
以上是配置文件部分,接下来来看具体代码。
三、通用DAO层Hibernate4实现
为了减少各模块实现的代码量,实际工作时都会有通用DAO层实现,以下是部分核心代码:
java代码: - publicabstractclass BaseHibernateDao<M extends java.io.Serializable, PK extends java.io.Serializable> implements IBaseDao<M, PK> {
-
- protectedstaticfinal Logger LOGGER = LoggerFactory.getLogger(BaseHibernateDao.class);
-
- privatefinal Class<M> entityClass;
- privatefinal String HQL_LIST_ALL;
- privatefinal String HQL_COUNT_ALL;
- privatefinal String HQL_OPTIMIZE_PRE_LIST_ALL;
- privatefinal String HQL_OPTIMIZE_NEXT_LIST_ALL;
- private String pkName = null;
-
- @SuppressWarnings("unchecked")
- public BaseHibernateDao() {
- this.entityClass = (Class<M>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
- Field[] fields = this.entityClass.getDeclaredFields();
- for(Field f : fields) {
- if(f.isAnnotationPresent(Id.class)) {
- this.pkName = f.getName();
- }
- }
-
- Assert.notNull(pkName);
- //TODO @Entity name not null
- HQL_LIST_ALL = "from " + this.entityClass.getSimpleName() + " order by " + pkName + " desc";
- HQL_OPTIMIZE_PRE_LIST_ALL = "from " + this.entityClass.getSimpleName() + " where " + pkName + " > ? order by " + pkName + " asc";
- HQL_OPTIMIZE_NEXT_LIST_ALL = "from " + this.entityClass.getSimpleName() + " where " + pkName + " < ? order by " + pkName + " desc";
- HQL_COUNT_ALL = " select count(*) from " + this.entityClass.getSimpleName();
- }
-
- @Autowired
- @Qualifier("sessionFactory")
- private SessionFactory sessionFactory;
-
- public Session getSession() {
- //事务必须是开启的,否则获取不到
- return sessionFactory.getCurrentSession();
- }
- ……
- }
public abstract class BaseHibernateDao<M extends java.io.Serializable, PK extends java.io.Serializable> implements IBaseDao<M, PK> {
protected static final Logger LOGGER = LoggerFactory.getLogger(BaseHibernateDao.class);
private final Class<M> entityClass;
private final String HQL_LIST_ALL;
private final String HQL_COUNT_ALL;
private final String HQL_OPTIMIZE_PRE_LIST_ALL;
private final String HQL_OPTIMIZE_NEXT_LIST_ALL;
private String pkName = null;
@SuppressWarnings("unchecked")
public BaseHibernateDao() {
this.entityClass = (Class<M>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
Field[] fields = this.entityClass.getDeclaredFields();
for(Field f : fields) {
if(f.isAnnotationPresent(Id.class)) {
this.pkName = f.getName();
}
}
Assert.notNull(pkName);
//TODO @Entity name not null
HQL_LIST_ALL = "from " + this.entityClass.getSimpleName() + " order by " + pkName + " desc";
HQL_OPTIMIZE_PRE_LIST_ALL = "from " + this.entityClass.getSimpleName() + " where " + pkName + " > ? order by " + pkName + " asc";
HQL_OPTIMIZE_NEXT_LIST_ALL = "from " + this.entityClass.getSimpleName() + " where " + pkName + " < ? order by " + pkName + " desc";
HQL_COUNT_ALL = " select count(*) from " + this.entityClass.getSimpleName();
}
@Autowired
@Qualifier("sessionFactory")
private SessionFactory sessionFactory;
public Session getSession() {
//事务必须是开启的,否则获取不到
return sessionFactory.getCurrentSession();
}
……
}
Spring3.1集成Hibernate4不再需要HibernateDaoSupport和HibernateTemplate了,直接使用原生API即可。
四、通用Service层代码 此处省略,看源代码,有了通用代码后CURD就不用再写了。
java代码: - @Service("UserService")
- publicclass UserServiceImpl extends BaseService<UserModel, Integer> implements UserService {
-
- privatestaticfinal Logger LOGGER = LoggerFactory.getLogger(UserServiceImpl.class);
-
- private UserDao userDao;
-
- @Autowired
- @Qualifier("UserDao")
- @Override
- publicvoid setBaseDao(IBaseDao<UserModel, Integer> userDao) {
- this.baseDao = userDao;
- this.userDao = (UserDao) userDao;
- }
-
-
-
- @Override
- public Page<UserModel> query(int pn, int pageSize, UserQueryModel command) {
- return PageUtil.getPage(userDao.countQuery(command) ,pn, userDao.query(pn, pageSize, command), pageSize);
- }
- }
@Service("UserService")
public class UserServiceImpl extends BaseService<UserModel, Integer> implements UserService {
private static final Logger LOGGER = LoggerFactory.getLogger(UserServiceImpl.class);
private UserDao userDao;
@Autowired
@Qualifier("UserDao")
@Override
public void setBaseDao(IBaseDao<UserModel, Integer> userDao) {
this.baseDao = userDao;
this.userDao = (UserDao) userDao;
}
@Override
public Page<UserModel> query(int pn, int pageSize, UserQueryModel command) {
return PageUtil.getPage(userDao.countQuery(command) ,pn, userDao.query(pn, pageSize, command), pageSize);
}
}
五、表现层 Controller实现
采用SpringMVC支持的REST风格实现,具体看代码,此处我们使用了java Validator框架 来进行 表现层数据验证
在Model实现上加验证注解
java代码: - @Pattern(regexp = "[A-Za-z0-9]{5,20}", message = "{username.illegal}") //java validator验证(用户名字母数字组成,长度为5-10)
- private String username;
- @NotEmpty(message = "{email.illegal}")
- @Email(message = "{email.illegal}") //错误消息会自动到MessageSource中查找
- private String email;
- @Pattern(regexp = "[A-Za-z0-9]{5,20}", message = "{password.illegal}")
- private String password;
- @DateFormat( message="{register.date.error}")//自定义的验证器
- private Date registerDate;
@Pattern(regexp = "[A-Za-z0-9]{5,20}", message = "{username.illegal}") //java validator验证(用户名字母数字组成,长度为5-10)
private String username;
@NotEmpty(message = "{email.illegal}")
@Email(message = "{email.illegal}") //错误消息会自动到MessageSource中查找
private String email;
@Pattern(regexp = "[A-Za-z0-9]{5,20}", message = "{password.illegal}")
private String password;
@DateFormat( message="{register.date.error}")//自定义的验证器
private Date registerDate;
在Controller中相应方法的需要验证的参数上加@Valid即可
java代码: - @RequestMapping(value = "/user/add", method = {RequestMethod.POST})
- public String add(Model model, @ModelAttribute("command") @Valid UserModel command, BindingResult result)
@RequestMapping(value = "/user/add", method = {RequestMethod.POST})
public String add(Model model, @ModelAttribute("command") @Valid UserModel command, BindingResult result)
六、Spring集成测试
使用Spring集成测试能很方便的进行Bean的测试,而且使用@TransactionConfiguration(transactionManager = "txManager", defaultRollback = true)能自动回滚事务,清理测试前后状态。
java代码: - @RunWith(SpringJUnit4ClassRunner.class)
- @ContextConfiguration(locations = {"classpath:spring-config.xml"})
- @Transactional
- @TransactionConfiguration(transactionManager = "txManager", defaultRollback = true)
- publicclass UserServiceTest {
-
- AtomicInteger counter = new AtomicInteger();
-
- @Autowired
- private UserService userService;
- ……
- }
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:spring-config.xml"})
@Transactional
@TransactionConfiguration(transactionManager = "txManager", defaultRollback = true)
public class UserServiceTest {
AtomicInteger counter = new AtomicInteger();
@Autowired
private UserService userService;
……
}
补充spring3.1.1源代码分析当 传播行为为 Support时报 org.hibernate.HibernateException: No Session found for current thread 异常:
spring3.1开始 不提供(没有这个东西了)Hibernate4的 DaoSupport和Template,,而是直接使用原生的Hibernate4 API
如在 Hibernate3中 HibernateTemplate中有如下代码
- protected Session getSession() {
- if (isAlwaysUseNewSession()) {
- return SessionFactoryUtils.getNewSession(getSessionFactory(), getEntityInterceptor());
- }
- else if (isAllowCreate()) {//默认是true,也就是即使你的传播行为是Supports也一定会有session存在的
- return SessionFactoryUtils.getSession(
- getSessionFactory(), getEntityInterceptor(), getJdbcExceptionTranslator());
- }
- else if (SessionFactoryUtils.hasTransactionalSession(getSessionFactory())) {
- return SessionFactoryUtils.getSession(getSessionFactory(), false);
- }
- else {
- try {
- return getSessionFactory().getCurrentSession();
- }
- catch (HibernateException ex) {
- throw new DataAccessResourceFailureException("Could not obtain current Hibernate Session", ex);
- }
- }
- }
但我们使用的是Hibernate4原生API,使用SpringSessionContext获取session,而这个isAllowCreate选项默认为false
- /**
- * Retrieve the Spring-managed Session for the current thread, if any.
- */
- public Session currentSession() throws HibernateException {
- try {
- return (org.hibernate.classic.Session) SessionFactoryUtils.doGetSession(this.sessionFactory, false);//最后的false即是
- }
- catch (IllegalStateException ex) {
- throw new HibernateException(ex.getMessage());
- }
- }
SessionFactoryUtils类
- public static Session doGetSession(SessionFactory sessionFactory, boolean allowCreate)
- throws HibernateException, IllegalStateException {
-
- return doGetSession(sessionFactory, null, null, allowCreate);
- }