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spring-mvc 系列：视图（ThymeleafView、InternalResourceView、RedirectView）

发布时间 2023-08-07 22:55:07作者: IT技术派

目录

SpringMVC中的视图是View接口，视图的作用渲染数据，将模型Model中的数据展示给用户

SpringMVC视图的种类很多，默认有转发视图和重定向视图

当工程引入jstl的依赖，转发视图会自动转换为JstlView若使用的视图技术为Thymeleaf，在SpringMVC的配置文件中配置了Thymeleaf的视图解析器，由此视图解析器解析之后所得到的是ThymeleafView

一、ThymeleafView

当控制器方法中所设置的视图名称没有任何前缀时，此时的视图名称会被SpringMVC配置文件中所配置的视图解析器解析，视图名称拼接视图前缀和视图后缀所得到的最终路径，会通过转发的方式实现跳转

html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>首页</h1>
<a th:href="@{/testThymeleafView}">测试ThymeleafView</a>
</body>
</html>

java

package com.mcode.api.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * ClassName: ViewController
 * Package: com.mcode.api.controller
 * Description:
 *
 * @Author: robin
 * @Create: 2023/8/7 - 9:06 PM
 * @Version: v1.0
 */
@Controller
public class ViewController {
    @RequestMapping("/")
    public String index(){
        return "index";
    }
    @RequestMapping("/testThymeleafView")
    public  String testThymeleafView(){
        return "success";
    }
}

DispatcherServlet.render()

AbstractCachingViewResolver.resolveViewName()

ThymeleafViewResolver.createView()

image

image

二、转发视图

SpringMVC中默认的转发视图是InternalResourceView

SpringMVC中创建转发视图的情况：

当控制器方法中所设置的视图名称以"forward:"为前缀时，创建InternalResourceView视图，此时的视图名称不会被SpringMVC配置文件中所配置的视图解析器解析，而是会将前缀"forward:"去掉，剩余部分作为最终路径通过转发的方式实现跳转

例如"forward:/"，"forward:/employee"

html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>首页</h1>
<a th:href="@{/testThymeleafView}">测试ThymeleafView</a>
<a th:href="@{/testForward}">测试InternalResourceView</a>
</body>
</html>

java

package com.mcode.api.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * ClassName: ViewController
 * Package: com.mcode.api.controller
 * Description:
 *
 * @Author: robin
 * @Create: 2023/8/7 - 9:06 PM
 * @Version: v1.0
 */
@Controller
public class ViewController {
    @RequestMapping("/")
    public String index(){
        return "index";
    }
    @RequestMapping("/testThymeleafView")
    public  String testThymeleafView(){
        return "success";
    }

    @RequestMapping("/testForward")
    public String testForward(){
        return "forward:/testThymeleafView";
    }
}

image

image

image

三、重定向视图

SpringMVC中默认的重定向视图是RedirectView

当控制器方法中所设置的视图名称以"redirect:"为前缀时，创建RedirectView视图，此时的视图名称不会被SpringMVC配置文件中所配置的视图解析器解析，而是会将前缀"redirect:"去掉，剩余部分作为最终路径通过重定向的方式实现跳转

html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>首页</h1>
<a th:href="@{/testThymeleafView}">测试ThymeleafView</a>
<a th:href="@{/testForward}">测试InternalResourceView</a>
<a th:href="@{/testRedirect}">测试Redirect</a>
</body>
</html>

java

package com.mcode.api.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * ClassName: ViewController
 * Package: com.mcode.api.controller
 * Description:
 *
 * @Author: robin
 * @Create: 2023/8/7 - 9:06 PM
 * @Version: v1.0
 */
@Controller
public class ViewController {
    @RequestMapping("/")
    public String index(){
        return "index";
    }
    @RequestMapping("/testThymeleafView")
    public  String testThymeleafView(){
        return "success";
    }

    @RequestMapping("/testForward")
    public String testForward(){
        return "forward:/testThymeleafView";
    }

    @RequestMapping("/testRedirect")
    public String testRedirect(){
        return "redirect:/testThymeleafView";
    }
}

image

image

image

注：重定向视图在解析时，会先将redirect:前缀去掉，然后会判断剩余部分是否以/开头，若是则会自动拼接上下文路径

四、视图控制器view-controller

当控制器方法中，仅仅用来实现页面跳转，即只需要设置视图名称时，可以将处理器方法使用view-controller标签进行表示

<?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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <context:component-scan base-package="com.mcode.api.controller"/>

    <!-- 配置Thymeleaf视图解析器 -->
    <bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="order" value="1"/>
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">

                        <!-- 视图前缀 -->
                        <property name="prefix" value="/WEB-INF/templates/"/>

                        <!-- 视图后缀 -->
                        <property name="suffix" value=".html"/>
                        <property name="templateMode" value="HTML5"/>
                        <property name="characterEncoding" value="UTF-8"/>
                    </bean>
                </property>
            </bean>
        </property>
    </bean>

    <!--    path：设置处理的请求地址 view-name：设置请求地址所对应的视图名称 -->
    <mvc:view-controller path="/" view-name="index"/>

    <!--  开启mvc注解驱动  -->
    <mvc:annotation-driven/>
</beans>

@Controller
public class ViewController {
//    @RequestMapping("/")
//    public String index(){
//        return "index";
//    }
}

注：当SpringMVC中设置任何一个view-controller时，其他控制器中的请求映射将全部失效，此时需要在SpringMVC的核心配置文件中设置开启mvc注解驱动的标签：<mvc:annotation-driven />

五、配置jsp解析

<?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 https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
    <context:component-scan base-package="com.mcode.api.controller"/>

    <!-- 配置Thymeleaf视图解析器 -->
    <bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="order" value="1"/>
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">

                        <!-- 视图前缀 -->
                        <property name="prefix" value="/WEB-INF/templates/"/>

                        <!-- 视图后缀 -->
                        <property name="suffix" value=".html"/>
                        <property name="templateMode" value="HTML5"/>
                        <property name="characterEncoding" value="UTF-8"/>
                    </bean>
                </property>
            </bean>
        </property>
    </bean>

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!--    jsp前缀    -->
        <property name="prefix" value="/jsp/"/>
        <!--     jsp后缀   -->
        <property name="suffix" value=".jsp"/>
        <!--    配置优先等级，越小优先级越高    -->
        <property name="order" value="0"/>
    </bean>

    <!--    path：设置处理的请求地址 view-name：设置请求地址所对应的视图名称 -->
    <mvc:view-controller path="/" view-name="index"/>

    <!--  开启mvc注解驱动  -->
    <mvc:annotation-driven/>
</beans>

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>首页</h1>
<a href="${pageContext.request.contextPath}/success">success.jsp</a>
</body>
</html>

web.xml

<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_4_0.xsd"
         version="4.0">

注：${pageContext.request.contextPath } 无效大多情况下是由于web.xml版本太低导致的，现在普遍都再用web4.0版本，web-app的版本默认是2.3，而要正确解析上面的代码获得当前路径，我们需要把web-app的版本手动改成2.5及以上版本。

image

控制器

package com.mcode.api.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * ClassName: JSPController
 * Package: com.mcode.api.controller
 * Description:
 *
 * @Author: robin
 * @Create: 2023/8/7 - 10:16 PM
 * @Version: v1.0
 */
@Controller
public class JSPController {
    @RequestMapping("/success")
    public String success(){
        return "success";
    }
}

image