The addresses we use in jsp and html are all addresses in the front-end page. Such addresses that do not start with the protocol are relative addresses:

We use domain names to access web pages on the Internet, such as: https://www.baidu.com . This type of address with a protocol name is an absolute address.

The relative address in SpringMVC will be accessed through the current address (reference address) + relative address splicing out the absolute address:

1. The relative address does not start with /:

After the project is started, the address bar url of the browser is our reference address: http://localhost:8080/SpringMVC_01/ , the relative address is spliced to get the absolute address:

2. Relative addresses beginning with /

We found that the reference address of the project became http://localhost:8080 at this time , and the resource path accessed after splicing was wrong. In fact, the relative address that starts with /, the reference address he uses is the host name, missing the project name; if you must use this method, you need to add the project name (using EL expressions to dynamically obtain):

3. Comparison of advantages

Although it seems simple to not start with /, it also has disadvantages. We don't use the view parser and let the page jump back to index.jsp:

    @RequestMapping(value = "/some.do" , method = RequestMethod.GET)
    public ModelAndView doSome(){
        ModelAndView modelAndView = new ModelAndView();

        // 存放数据 框架会自动将数据放到request作用域
        modelAndView.addObject("msg","hello-get");

        modelAndView.setViewName("/index.jsp");

        return modelAndView;
    }

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       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-3.1.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-3.1.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">

    <!--声明组件扫描器-->
    <context:component-scan base-package="com.zzt.Controller"/>

    <!--配置视图解析器-->
    <!--<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/view/"/>
        <property name="suffix" value=".jsp"/>
    </bean>-->

    <!--配置注解驱动-->
    <mvc:annotation-driven/>

    <!--静态资源处理 方式1
    <mvc:default-servlet-handler/>-->

    <!--静态资源处理 方式2-->
    <mvc:resources mapping="/static/**" location="/static/" />


</beans>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <a href="test/some.do">发起some.do请求</a>
</body>
</html>

Note that SpringMVC uses the forward method, so the URL will not change with the jump. At this time, the address can be parsed as follows:

Reference path: http://localhost:8080/SpringMVC_02/test/

Source: some.do

What if we make another request at this time?

We use a method that does not start with /, but when we initiate the second request, the reference path is different from the first one. Through splicing, add it after http://localhost:8080/SpringMVC_02/test/ The relative address of the resource, test/some.do , is http://localhost:8080/SpringMVC_02/test/test/some.do , which obviously has no mapping to it, nor is it a static resource.

Solution 1: Add dynamic project name

<a href="${pageContext.request.contextPath}/test/some.do">发起some.do请求</a>

Solution 2: Use the <base> tag in html to fix the base address. All relative addresses that do not start with / will use the base address as the reference address

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <base href="http://localhost:8080/SpringMVC_02/">
</head>
<body>
    <a href="test/some.do">发起some.do请求</a>
</body>
</html>

Of course, it is impossible for us to write the base address of a base tag separately for each page. Therefore, we can also dynamically obtain the project address in jsp:

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%
    String basePath = request.getScheme()+ "://" +
            request.getServerName() + ":" + request.getServerPort() +
            request.getContextPath() + "/";
%>
<html>
<head>
    <title>Title</title>
    <base href="<%=basePath%>" />
</head>
<body>
    <a href="test/some.do">发起some.do请求</a>
</body>
</html>

SpringMVC study notes -07 path address

1. The relative address does not start with /:

2. Relative addresses beginning with /

3. Comparison of advantages

Guess you like