springmvc的两个处理器适配器(四)

拼搏现实的明天。 2022-06-12 04:29 127阅读 0赞

1.SimpleControllerHandlerAdapter(默认)  
  
使用该处理器适配器需要自定义Controller实现Controller接口,否则会找不到对应的controller  
默认的Controller适配器

<bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>

SimpleControllerHandlerAdapter源码

public class SimpleControllerHandlerAdapter implements HandlerAdapter { 
    
        public boolean supports(Object handler) {
            return (handler instanceof Controller);
        }
    
        public ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
                throws Exception {
    
            return ((Controller) handler).handleRequest(request, response);
        }
    
        public long getLastModified(HttpServletRequest request, Object handler) {
            if (handler instanceof LastModified) {
                return ((LastModified) handler).getLastModified(request);
            }
            return -1L;
        }
    }

通过查看源码可知,需要先判断自定义的controller是否实现的Controller接口才会执行后面的方法  
![这里写图片描述][SouthEast]

2.HttpRequestHandlerAdapter  
  
HttpRequestHandlerAdapter处理器适配器将http请求封装成HttpServletResquest 和HttpServletResponse对象，和servlet接口类似

1.配置xml文件

<bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter"></bean>

2.自定义Controller

public class HtppController implements HttpRequestHandler{ 
    
        public void handleRequest(HttpServletRequest request, HttpServletResponse respone) throws ServletException, IOException {
            request.setAttribute("hello", "sprinmvc,又见面了!");
            request.getRequestDispatcher("/WEB-INF/jsps/index.jsp").forward(request, respone);
        }
    
    }

3.将自定义的Controller交给spring管理

4.jsp页面显示结果

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>springmvc</title>
    </head>
    <body>
        ${hello }
    </body>
    </html>

注:两个处理器适配器是可以共存的.

[SouthEast]: /images/20220612/ee8f645e80124720adf6c4346cd49573.png