Spring mvc系列三之 开启注解

spring mvc 基于注解的使用,相当于配置文件的使用简单的多.下面讲一下spring mvc 注解的使用

先首确保已经把spring mvc的环境搭配好.这里可以看我的前一篇文章Spring mvc系列一之 Spring mvc简单配置.

先看一下再未使用注解前,spring mvc的配置文件

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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">

<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<propertyname="prefix"value="/"/>
<propertyname="suffix"value=".jsp"/>
</bean>

<!--声明一个Controller中使用多个方法-->
<beanid="parameterMethodNameResolver"class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver">
<!--传参数时用这个作为名称-->
<propertyname="paramName"value="action"></property>
</bean>

<!--声明DispatcherServlet不要拦截下面声明的目录-->
<mvc:resourceslocation="/images/"mapping="/images/**"/>

</beans>

上面我们声明在一个控制器中使用多个方法.

再看看spring mvc使用注解配置文件的配置:

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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">
<!--开启注解扫描功能-->
<context:component-scanbase-package="gd.hz.springmvc.controller"></context:component-scan>

<!--开启注解DefaultAnnotationHandlerMapping:映射相应的类,DefaultAnnotationHandlerMapping相应的类方法-->
<beanclass="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"></bean>
<beanclass="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"></bean>

<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<propertyname="prefix"value="/"/>
<propertyname="suffix"value=".jsp"/>
</bean>

</beans>

上面我们开启了注解扫描,注入了AnnotationMethodHandlerAdapter作用是对有RequestMapping注解的控制器进行HTTP路径、HTTP方法和请求参数解析.DefaultAnnotationHandlerMapping作用是映射处理程序方法级别的HTTP路径.在spring 3.1之后由RequestMappingHandlerAdapter和RequestMappingHandlerMapping代替.

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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">
<!--开启注解扫描功能-->
<context:component-scanbase-package="gd.hz.springmvc.controller"></context:component-scan>

<!--开启注解DefaultAnnotationHandlerMapping:映射相应的类,DefaultAnnotationHandlerMapping相应的类方法-->
<!--
<beanclass="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"></bean>
<beanclass="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"></bean>
-->

<!--spring3.1之后由RequestMappingHandlerAdapter和RequestMappingHandlerMapping代替-->
<beanclass="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"></bean>
<beanclass="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"></bean>


<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<propertyname="prefix"value="/"/>
<propertyname="suffix"value=".jsp"/>
</bean>

<!--声明DispatcherServlet不要拦截下面声明的目录-->
<mvc:resourceslocation="/images/"mapping="/images/**"/>
</beans>

上面的两个注解也可以用mvc标签表示,spring 3.1之后默认注入的是RequestMappingHandlerAdapter和RequestMappingHandlerMapping:

<?xmlversion="1.0"encoding="UTF-8"?>
<beansxmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:p="http://www.springframework.org/schema/p"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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">
<!--开启注解扫描功能-->
<context:component-scanbase-package="gd.hz.springmvc.controller"></context:component-scan>

<mvc:annotation-driven/>

<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<propertyname="prefix"value="/"/>
<propertyname="suffix"value=".jsp"/>
</bean>
</beans>

接下来新建一个控制器:

packagegd.hz.springmvc.controller;

importorg.springframework.stereotype.Controller;
importorg.springframework.web.bind.annotation.RequestMapping;
importorg.springframework.web.servlet.ModelAndView;

@Controller("userController")
publicclassUserController{
@RequestMapping("addUser")
publicModelAndViewaddUser()
{
returnnewModelAndView("hello");
}
}

注解@Controller标志该类为控制器.注解@RequestMapping,映射相应的路径.

我们可以这样访问:http://localhost/Springmvc/addUser ,其中addUser 就是@RequestMapping映射的名称,名字随意.下一章我们将对spring mvc的注解进行介绍.