SpringMVC 视图解析器

SpringMVC 视图解析器

还记得SpringMVC 快速入门中,dispatcher-servlet.xml 配置的视图解析器么。它是SpringMVC 的核心知识点。本章节比较简单,明白视图解析器的工作原理,然后配置自定义的视图解析器和使用重点向跳转页面。

SpringMVC的配置文件,dispatcher-servlet.xml。这里配置了直接跳转的页面 mvc:view-controller 即不经过Controller层,直接根据视图解析器跳转页面。还配置了视图解析器 BeanNameViewResolver 优先级为666。其中jsp最为常见的解析器是 InternalResourceViewResolver 器优先级是int类型的最大值。也就是说优先级最低。

<?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-4.0.xsd  
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">  
  
    <!-- 配置自定扫描的包 -->  
    <context:component-scan base-package="com.itdragon.springmvc" />  
  
    <!-- 配置视图解析器 -->  
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <property name="prefix" value="/WEB-INF/views/"></property>  
        <property name="suffix" value=".jsp"></property>  
    </bean>  
      
    <!-- 配置注解驱动 -->  
    <mvc:annotation-driven />  
  
    <!-- 配置视图  BeanNameViewResolver 解析器  
        使用视图的名字来解析视图   
        通过 order 属性来定义视图解析器的优先级, order 值越小优先级越高  
    -->  
    <bean class="org.springframework.web.servlet.view.BeanNameViewResolver">  
        <property name="order" value="666"></property>  
    </bean>  
      
    <!-- 配置直接跳转的页面,无需经过Controller层    
        http://localhost:8080/springmvc/index   
        然后会跳转到 WEB-INF/views/index.jsp 页面  
    -->  
    <mvc:view-controller path="/index" view-name="index"/>  
</beans>  

自定义CustomViewResolver java类 实现 View 接口。

import java.util.Map;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import org.springframework.stereotype.Component;  
import org.springframework.web.servlet.View;  
  
@Component  
public class CustomViewResolver implements View{  
  
    public String getContentType() {  
        return "text/html";  
    }  
  
    public void render(Map<String, ?> model, HttpServletRequest request,  
            HttpServletResponse response) throws Exception {  
        response.setCharacterEncoding("utf-8");  
        response.setContentType("text/html;charset=utf-8");  
        response.getWriter().print("CustomViewResolver order 越小优先级越高! 所以优先于 InternalResourceViewResolver");  
    }  
  
}  

语法知识点说明类 ViewResolverController

import org.springframework.stereotype.Controller;  
import org.springframework.web.bind.annotation.RequestMapping;  
  
@Controller  
public class ViewResolverController {  
      
    @RequestMapping("/testRedirect")  
    public String testRedirect() {  
        System.out.println("^^^^^^^^^^^^^^^^^^^^^重定向到apistudy.jsp页面,地址栏URL改变");  
        return "redirect:apiStudy/testModelAndView";  
    }  
      
    @RequestMapping("/testForward")  
    public String testForward() {  
        System.out.println("^^^^^^^^^^^^^^^^^^^^^转发到apistudy.jsp页面,地址栏URL不变");  
        return "forward:apiStudy/testModelAndView";  
    }  
      
    @RequestMapping("/testCustomViewResolver")  
    public String testCustomViewResolver() {  
        System.out.println("^^^^^^^^^^^^^^^^^^^^^进入到自定义的视图解析器中,返回值必须是类名首字母小写");  
        return "customViewResolver";  
    }  
  
}  

WEB-INF/views/index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"  
    pageEncoding="UTF-8"%>  
      
<!DOCTYPE>  
<html>  
<head>  
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
<title>SpringMVC 快速入门</title>  
</head>  
<body>  
      
    <h2>视图解析器</h2>  
    <a href="testRedirect">Test Redirect</a>  
    <br/><br/>  
    <a href="testForward">Test Forward</a>  
    <br/><br/>  
    <a href="testCustomViewResolver">Test Custom View Resolver</a>  
    <br/><br/>  
      
</body>  
</html>  

运行的效果图

们装配成ModelAndView对象,
然后,借助视图解析器 ViewResolver,得到最终的逻辑视图对象View。最终的物理视图可以是jsp,excel,表单 等各种表现形式的视图。

到这里SpringMVC 的视图解析器就介绍完了,下一章是重难点,SpringMVC Form表单的crud操作。

posted @ 2017-10-23 17:57  ITDragon龙  阅读(1391)  评论(0编辑  收藏