Spring 学习经验总结

转载自 http://blog.youkuaiyun.com/wangyang1354/article/details/48198411

Bean的作用范围
.singleton 默认的形式，在Spring的IOC容器中默认情况下只有一个对象的实例。
.prototype 每次从容器中获取的bean都是新的对象。
.request
.response
.global session

1. Spring中Bean（默认的单例模式下）实例化的时间：容器实例化的时候。设置lay-init=“true”的时候会在getBean的时候才会实例化。
2. 如果范围是prototype的时候，实在getBean的时候进行实例化的。

Init-method 当bean被实例化之后会自动执行init-method中的方法。
Destroy-method 当bean被销毁的时候自动执行里面的方法。


基本的原理总结为：
Xml配置文件中定义了很多属性，与之对应的创建一个含有这些类型的属性的类。
通过读取XML中这些属性的值，填入到对应的那个类的属性当中去。
在这个类中完成实例化bean对象，注入对象等操作


依赖注入的两种方式：
1.<bean id = “userDao” name = “userDao” class = “com.siti.entity.UserDaoImpl” />
  <bean id = “userService” name = “userService” class = “com.siti.service.UserServiceImpl”>
<property name = “userDao” ref = “userDao”></property>
  </bean>

2.使用内部bean的方式，但是这样的话这个bean就不能被其他的bean使用了
<bean id = “userDao” name = “userDao” class = “com.siti.service.UserServiceImpl”>
<property name = “userDao”>
<bean class = “com.siti.entity.UserDaoImpl” />
</property>
</bean>


构造方法注入依赖对象和值
pulic void UserService(UserDao userDao , String name)
{

}
<bean id = “userDao” name = “userDao” class = “com.siti.entity.UserDaoImpl” />
<bean id = “userService” class = “com.siti.serviceimpl.UserServiceImpl”>
<constructor-arg index = “0” type = “com.siti.dao.UserDao” ref = “userDao”/>
<constructor-arg index = “1” type = “nihao”></constructor-arg>
</bean>


@Autowired是spring框架的，但是@Resource集成到了Javaee里面了（不建议使用）

配置文件中写

<context:annotation-config/>
<bean id = “userDao” class = “com.siti.impl.UserDaoImpl”/>
<bean id = “userServiceImpl” class = “com.siti.service.impl.UserServiceImpl’ />

同在UserServiceImpl中属性之前加上@Resource就可以啦

可以加参数@Resource(name = “userDao”)

@Autowired与@Resource使用一样的。
Autowired(required = true) 默认是必须注入的
@Autowired @Qualifier(“userDao”) 按名进行装配

Spring自动扫描
<context：component-scan  base-package = “com.siti/>”
在Dao的实现类中标注：@Repository
在service类中@Service（中间可以指定其名称）标注会自动的将对象交给spring进行管理
@Scope指定作用域范围
指定初始化方法：@PostConstruct
指定关闭资源的函数：@PreDestroy

AOP代理对象

基于注解的方式实现
首先启动对@AspectJ注解的支持<aop:aspectj-autoproxy/>以及引入AOP的命名空间http://www............
例如
<?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"      
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
        <aop:aspectj-autoproxy/> 
        <bean id="myInterceptor" class="cn.siti.service.MyInterceptor"/>
        <bean id="personService" class="cn.siti.service.impl.PersonServiceBean"></bean>
</beans>

@Pointcut(“execution (*  cn.siti.service.. * . * (..))”)
Execution表示执行，*表示返回值的类型（*是任何的类型），cn.siti.service表示在哪个包下面进行拦截，后面的两个点表示对于它的子包底下的类也要进行拦截，后面的*表示包下面的类*表示所有类，后面的*表示方法，后面的括号（. . ）表示参数随意


@Aspect
public class MyInterceptor {
    @Pointcut("execution (* cn.itcast.service.impl.PersonServiceBean.*(..))")
    private void anyMethod() {} //声明切入点

    @Before("anyMethod() && args(name)")
    public void doAccessCheck(String name) {
        System.out.println("前置通知:"+ name);
    }
    @AfterReturning(pointcut="anyMethod()",returning="result")
    public void doAfterReturning(String result) {
        System.out.println("后置通知:"+ result);
    }
    @After("anyMethod()")---->最后一定会执行的
    public void doAfter() {
        System.out.println("最终通知！");
    }
    @AfterThrowing(pointcut="anyMethod()",throwing="e")
    public void doAfterThrowing(Exception e) {
        System.out.println("例外通知:"+ e);
    }

    @Around("anyMethod()")
    public Object doBasicProfiling(ProceedingJoinPoint pjp) throws Throwable {
        //if(){//判断用户是不是有权限
        System.out.println("环绕通知");
        Object result = pjp.proceed();
        System.out.println("运行");
        //}
        return result;
    }


使用配置文件配置的方式

<?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"      
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
        <aop:aspectj-autoproxy/> 
        <bean id="personService" class="cn.itcast.service.impl.PersonServiceBean"></bean>
        <bean id="aspetbean" class="cn.itcast.service.MyInterceptor"/>
        <aop:config>
        <aop:aspect id="asp" ref="aspetbean">
            <aop:pointcut id="mycut" expression="execution(* cn.itcast.service..*.*(..))"/>
            <aop:before pointcut-ref="mycut" method="doAccessCheck"/>
            <aop:after-returning pointcut-ref="mycut" method="doAfterReturning"/>
    <aop:after-throwing pointcut-ref="mycut" method="doAfterThrowing"/>
    <aop:after pointcut-ref="mycut" method="doAfter"/>
    <aop:around pointcut-ref="mycut" method="doBasicProfiling"/>
        </aop:aspect>
        </aop:config>
</beans>
Spring+JDBC组合开发
配置文件
<?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: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/context http://www.springframework.org/schema/context/spring-context-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">

     <context:property-placeholder location="classpath:jdbc.properties"/>
     <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${driverClassName}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
         <!-- 连接池启动时的初始值 -->
    <property name="initialSize" value="${initialSize}"/>
     <!-- 连接池的最大值 -->
     <property name="maxActive" value="${maxActive}"/>
     <!-- 最大空闲值.当经过一个高峰时间后，连接池可以慢慢将已经用不到的连接慢慢释放一部分，一直减少到maxIdle为止 -->
    <property name="maxIdle" value="${maxIdle}"/>
     <!--  最小空闲值.当空闲的连接数少于阀值时，连接池就会预申请去一些连接，以免洪峰来时来不及申请 -->
 <property name="minIdle" value="${minIdle}"/>
     </bean>

    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource" ref="dataSource"/>
    </bean>
    <tx:annotation-driven transaction-manager="txManager"/>

    <bean id="personService" class="cn.itcast.service.impl.PersonServiceBean">  <property name="dataSource" ref="dataSource"/>
       </bean>
</beans>

jdbc.properties
driverClassName=org.gjt.mm.mysql.Driver
url=jdbc\:mysql\://localhost\:3306/itcast?useUnicode\=true&characterEncoding\=UTF-8
username=root
password=123456
initialSize=1
maxActive=500
maxIdle=2
minIdle=1



注解的方式配置事务

Unchecked 运行期例外，事务会回滚的（默认的）
Checked 这种事务不会回滚（默认的方式）
对于checked这种事务要求回滚: @Transactional(rollbackFor = Exception.class)

不需要使用事务的话
@Transactional(propagation = Propagation.NOT_SUPPORTED)


采用基于XML的方式配置事务

建议使用注解的方式使用事务。




整合开发


Spring集成Hibernate二级缓存

<?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/context http://www.springframework.org/schema/context/spring-context-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">
     <context:annotation-config/>
     <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="org.gjt.mm.mysql.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/itcast?useUnicode=true&characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
         <!-- 连接池启动时的初始值 -->
         <property name="initialSize" value="1"/>
         <!-- 连接池的最大值 -->
         <property name="maxActive" value="500"/>
         <!-- 最大空闲值.当经过一个高峰时间后，连接池可以慢慢将已经用不到的连接慢慢释放一部分，一直减少到maxIdle为止 -->
         <property name="maxIdle" value="2"/>
         <!--  最小空闲值.当空闲的连接数少于阀值时，连接池就会预申请去一些连接，以免洪峰来时来不及申请 -->
         <property name="minIdle" value="1"/>
      </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
         <property name="dataSource" ref="dataSource"/>
         <property name="mappingResources">
            <list>
              <value>cn/itcast/bean/Person.hbm.xml</value>
            </list>
         </property>
         <property name="hibernateProperties">
            <value>
                hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
                hibernate.hbm2ddl.auto=update
                hibernate.show_sql=false
                hibernate.format_sql=false
                hibernate.cache.use_second_level_cache=true
                hibernate.cache.use_query_cache=false
                hibernate.cache.provider_class=org.hibernate.cache.EhCacheProvider
              </value>
         </property>
    </bean>
    <bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>
    <tx:annotation-driven transaction-manager="txManager"/>
    <bean id="personService" class="cn.itcast.service.impl.PersonServiceBean"/>
    <bean id="personList" class="cn.itcast.web.PersonAction"/>
</beans>



Spring 集成JPA



在src目录下创建META-INF文件夹，在下面创建persistentce.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="itcast" transaction-type="RESOURCE_LOCAL">
      <properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
         <property name="hibernate.connection.driver_class" value="org.gjt.mm.mysql.Driver"/>
         <property name="hibernate.connection.username" value="root"/>
         <property name="hibernate.connection.password" value="123456"/>
         <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/itcast?useUnicode=true&characterEncoding=UTF-8"/>
         <property name="hibernate.max_fetch_depth" value="3"/>
         <property name="hibernate.hbm2ddl.auto" value="update"/>
      </properties>
  </persistence-unit>
</persistence>


Spring的配置文件
<?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: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/context http://www.springframework.org/schema/context/spring-context-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">
     <context:annotation-config/>
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
      <property name="persistenceUnitName" value="itcast"/>
    </bean>
    <bean id="txManager" class="org.springframework.orm.jpa.JpaTransactionManager">
      <property name="entityManagerFactory" ref="entityManagerFactory"/>
   </bean>
    <tx:annotation-driven transaction-manager="txManager"/>
    <bean id="personService" class="cn.itcast.service.impl.PersonServiceBean"/>
    <bean name="/person/list" class="cn.itcast.web.action.PersonAction"/>
    <bean name="/person/manage" class="cn.itcast.web.action.PersonManageAction"/>
</beans>