RequestMapping注解
一.RequestMapping注解的作用是建立请求URL和处理方法之间的对应关系
二. RequestMapping注解可以作用在方法和类上
1. 作用在类上:第一级的访问目录
2. 作用在方法上:第二级的访问目录
3. 细节:路径可以不编写 / 表示应用的根目录开始
4. 细节:${ pageContext.request.contextPath }也可以省略不写,但是路径上不能写 /
三. RequestMapping的属性
1. path 指定请求路径的url
2. value value属性和path属性是一样的
3. mthod 指定该方法的请求方式
4. params 指定限制请求参数的条件
5. headers 发送的请求中必须包含的请求头
实例演示:
HelloController控制器类
package Controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
/**
* 控制器类
*/
@Controller
@RequestMapping("/user")
public class HelloController {
@RequestMapping("/sayHello")
public String sayHello(){
System.out.println("hello springmvc");
return "success" ;
}
@RequestMapping("/testRequestMapping")
public String testRequestMapping(){
System.out.println("测试RequestMapping注解...");
return "success" ;
}
@RequestMapping(value = "/postRequestMapping" , method = {RequestMethod.POST})
public String postRequestMapping(){
System.out.println("POST请求");
return "success" ;
}
@RequestMapping(value = "/paramsRequestMapping" , params = {"username"})
public String paramsRequestMapping (){
System.out.println("判断是否包含参数");
return "success" ;
}
}
index.jsp文件
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>调试程序</title>
</head>
<body>
<h3>调试程序</h3>
<a href="/user/sayHello">调试程序</a>
<br>
<a href="/user/testRequestMapping">RequestMapping</a>
<br>
<a href="/user/postRequestMapping">postRequestMapping</a>
<br>
<a href="/user/paramsRequestMapping?username=haha">paramsRequestMapping</a>
</body>
</html>
success.jsp文件
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>调试成功</h3>
</body>
</html>
web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
springmvc.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:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
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/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<context:component-scan base-package="Controller"/>
<!--配置映射器处理器,处理器适配器-->
<mvc:annotation-driven/>
<!--视图解析器-->
<bean id="ViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--释放静态资源-->
<mvc:default-servlet-handler/>
</beans>