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SpringMVC笔记：annotation注解式开发
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一、配置式开发
在我们之前的学习中，springmvc使用配置式开发模式，需要在核心配置文件中springmvc.xml注册大量的bean来注入controller控制器，工作繁琐容易出错，下面我们学习一下注解式开发来简化我们的工作。
。。。
案例：
1.控制器
public class MyMultiController extends MultiActionController {
/*第一个方法*/
public String doFirst(HttpServletRequest request, HttpServletResponse response){
System.out.println("执行方法一！！！");
return "first";
}
/*第二个方法*/
public String doSecond(HttpServletRequest request, HttpServletResponse response){
System.out.println("执行方法二！！！");
return "second";
}
}
2.spring注册
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--控制器映射-->
<bean class="cn.springmvc.day02handler.MyPropertiesController" id="myPropertiesController">
<property name="methodNameResolver" ref="methodNameResolver"></property>
</bean>
<!--方法名称解析器-->
<bean class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver" id="methodNameResolver">
<!--<property name="paramName" value="action"></property>-->
</bean>
<!--处理器映射器-->
<bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/hello.do">myPropertiesController</prop>
</props>
</property>
</bean>
<!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
3.访问
localhost:8080/hello.do?action=doFirst
-----------------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--porperties-->
<bean class="org.springframework.web.servlet.mvc.multiaction.PropertiesMethodNameResolver" id="propertiesMethodNameResolver">
<property name="mappings">
<props>
<prop key="/first.do">doFirst</prop>
<prop key="/second.do">doSecond</prop>
</props>
</property>
</bean>
<!--控制器映射器-->
<bean class="cn.springmvc.day02handler.MyPropertiesController" id="myPropertiesController">
<property name="methodNameResolver" ref="propertiesMethodNameResolver"></property>
</bean>
<!--映射器配置-->
<bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/*.do">myPropertiesController</prop>
</props>
</property>
</bean> <!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<!--前缀 prefix-->
<property name="prefix" value="/"></property>
<!--后缀 suffix-->
<property name="suffix" value=".jsp"></property>
</bean>
</beans>
访问：
localhost:8080/first.do | second.do
----------------------------------------------------
二、注解式开发
1.在控制器的类和方法上添加注解
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@Controllerpublic class MyAnnontation {
/*方法一*/
@RequestMapping("/first.do")
public ModelAndView getModel(HttpServletRequest request, HttpServletResponse response){
System.out.println("注解方法一！");
ModelAndView mv = new ModelAndView("first");
return mv;
} /*方法一*/
@RequestMapping("/second.do")
public ModelAndView getView(HttpServletRequest request, HttpServletResponse response){
System.out.println("注解方法二！");
ModelAndView mv = new ModelAndView("second");
return mv;
}
}
2.配置文件中添加注解驱动<mvc:annotation-driven/>
<?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:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--扫描controller-->
<context:component-scan base-package="cn.springmvc.annotation"></context:component-scan> <!--视图解析器-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"/>
<property name="suffix" value=".jsp"/>
</bean> <!--注解驱动-->
<mvc:annotation-driven></mvc:annotation-driven>
</beans>
3.简单访问
。。。
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Annotation</title>
</head>
<body>
<h1>未标明命名空间</h1>
<form action="/first.do" method="get">
<input type="submit" value="执行方法一">
</form>
<form action="/second.do" method="get">
<input type="submit" value="执行方法一">
</form>
<hr/>
<h1>已标明命名空间</h1>
<form action="/annotation/first.do" method="get">
<input type="submit" value="执行方法一">
</form>
<form action="/annotation/second.do" method="get">
<input type="submit" value="执行方法一">
</form>
</body>
</html>
三、注解式开发中引入命名空间来避免重名方法的混淆
1.在类名上添加RequestMapping("/name")注解即可区分
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;@Controller
/*命名空间*/
@RequestMapping("/annotation")
public class MyAnnontation {
/*方法一*/
@RequestMapping("/first.do")
public ModelAndView getModel(HttpServletRequest request, HttpServletResponse response){
System.out.println("注解方法一！");
ModelAndView mv = new ModelAndView("first");
return mv;
} /*方法一*/
@RequestMapping("/second.do")
public ModelAndView getView(HttpServletRequest request, HttpServletResponse response){
System.out.println("注解方法二！");
ModelAndView mv = new ModelAndView("second");
return mv;
}
}
