SpringMVC源码剖析1——执行流程

00.SpringMVC执行流程
file:///C:/Users/WANGGA~1/AppData/Local/Temp/enhtmlclip/Image.png
01.拦截所有的请求,访问DispatcherServlet
<ignore_js_op>
02.DispatcherServlet原理是一个Servlet,只要是Servlet就走doService方法
下面是DispatcherServlet的doService方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
protected void doService(HttpServletRequest request, HttpServletResponse response) throws Exception {
   if (logger.isDebugEnabled()) {
      String resumed = WebAsyncUtils.getAsyncManager(request).hasConcurrentResult() ? " resumed" : "";
      logger.debug("DispatcherServlet with name '" + getServletName() + "'" + resumed +
            " processing " + request.getMethod() + " request for [" + getRequestUri(request) + "]");
   }
 
 
   // Keep a snapshot of the request attributes in case of an include,
   // to be able to restore the original attributes after the include.
   Map<String, Object> attributesSnapshot = null;
   if (WebUtils.isIncludeRequest(request)) {
      attributesSnapshot = new HashMap<>();
      Enumeration<?> attrNames = request.getAttributeNames();
      while (attrNames.hasMoreElements()) {
         String attrName = (String) attrNames.nextElement();
         if (this.cleanupAfterInclude || attrName.startsWith(DEFAULT_STRATEGIES_PREFIX)) {
            attributesSnapshot.put(attrName, request.getAttribute(attrName));
         }
      }
   }
 
 
   // Make framework objects available to handlers and view objects.
   request.setAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE, getWebApplicationContext());
   request.setAttribute(LOCALE_RESOLVER_ATTRIBUTE, this.localeResolver);
   request.setAttribute(THEME_RESOLVER_ATTRIBUTE, this.themeResolver);
   request.setAttribute(THEME_SOURCE_ATTRIBUTE, getThemeSource());
 
 
   if (this.flashMapManager != null) {
      FlashMap inputFlashMap = this.flashMapManager.retrieveAndUpdate(request, response);
      if (inputFlashMap != null) {
         request.setAttribute(INPUT_FLASH_MAP_ATTRIBUTE, Collections.unmodifiableMap(inputFlashMap));
      }
      request.setAttribute(OUTPUT_FLASH_MAP_ATTRIBUTE, new FlashMap());
      request.setAttribute(FLASH_MAP_MANAGER_ATTRIBUTE, this.flashMapManager);
   }
 
 
   try {
      doDispatch(request, response);
   }
   finally {
      if (!WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {
         // Restore the original attribute snapshot, in case of an include.
         if (attributesSnapshot != null) {
            restoreAttributesAfterInclude(request, attributesSnapshot);
         }
      }
   }
}

前面都没啥用就是给request添加参数

03.doDispatch(request, response);方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
   HttpServletRequest processedRequest = request;
   HandlerExecutionChain mappedHandler = null;
   boolean multipartRequestParsed = false;
 
 
   WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
 
 
   try {
      ModelAndView mv = null;
      Exception dispatchException = null;
 
 
      try {
         processedRequest = checkMultipart(request);
         multipartRequestParsed = (processedRequest != request);
 
 
         // Determine handler for the current request. 这段代码是用来确定调用方法的,是根据路径解析出来的
         mappedHandler = getHandler(processedRequest);
         if (mappedHandler == null) {
            noHandlerFound(processedRequest, response);
            return;
         }
 
 
         // Determine handler adapter for the current request.
        //确定当前请求程序的适配器 [RequestMappingHandlerAdapter也是就@Controller 的适配器
         HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
 
 
         // Process last-modified header, if supported by the handler.
         String method = request.getMethod();
         boolean isGet = "GET".equals(method);
         if (isGet || "HEAD".equals(method)) {
            long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
            if (logger.isDebugEnabled()) {
               logger.debug("Last-Modified value for [" + getRequestUri(request) + "] is: " + lastModified);
            }
            if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {
               return;
            }
         }
 
 
         if (!mappedHandler.applyPreHandle(processedRequest, response)) {
            return;
         }
 
 
         // Actually invoke the handler.  通过反射调用相应执行的方法
         mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
 
 
         if (asyncManager.isConcurrentHandlingStarted()) {
            return;
         }
 
 
         applyDefaultViewName(processedRequest, mv);
         mappedHandler.applyPostHandle(processedRequest, response, mv);
      }
      catch (Exception ex) {
         dispatchException = ex;
      }
      catch (Throwable err) {
         // As of 4.3, we're processing Errors thrown from handler methods as well,
         // making them available for @ExceptionHandler methods and other scenarios.
         dispatchException = new NestedServletException("Handler dispatch failed", err);
      }
      processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
   }
   catch (Exception ex) {
      triggerAfterCompletion(processedRequest, response, mappedHandler, ex);
   }
   catch (Throwable err) {
      triggerAfterCompletion(processedRequest, response, mappedHandler,
            new NestedServletException("Handler processing failed", err));
   }
   finally {
      if (asyncManager.isConcurrentHandlingStarted()) {
         // Instead of postHandle and afterCompletion
         if (mappedHandler != null) {
            mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);
         }
      }
      else {
         // Clean up any resources used by a multipart request.
         if (multipartRequestParsed) {
            cleanupMultipart(processedRequest);
         }
      }
   }
}

04. mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
此方法主要是调用对应的适配器,然后再通过反射执行对应方法

本来应该调用RequestHandlerAdapter类中的方法,但是没有,根据继承的关系调用父类,抽象类AbstractHandlerMethodAdapter中的方法handle( )

[Java] 纯文本查看 复制代码
1
2
3
4
public final ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
      throws Exception {
   return handleInternal(request, response, (HandlerMethod) handler);
}

本类

[Java] 纯文本查看 复制代码
1
2
protected abstract ModelAndView handleInternal(HttpServletRequest request,HttpServletResponse response,
                                                                         HandlerMethod handlerMethod) throws Exception;

然后在RequestHandlerAdapter中调用 handleInternal( )方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
protected ModelAndView handleInternal(HttpServletRequest request,
      HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
 
 
   ModelAndView mav;
   checkRequest(request);
 
 
   // Execute invokeHandlerMethod in synchronized block if required.
   if (this.synchronizeOnSession) {
      HttpSession session = request.getSession(false);
      if (session != null) {
         Object mutex = WebUtils.getSessionMutex(session);
         synchronized (mutex) {
            mav = invokeHandlerMethod(request, response, handlerMethod);
         }
      }
      else {
         // No HttpSession available -> no mutex necessary
         mav = invokeHandlerMethod(request, response, handlerMethod);
      }
   }
   else {
      // No synchronization on session demanded at all...
      mav = invokeHandlerMethod(request, response, handlerMethod);
   }
SpringMVC源码剖析1——执行流程

00.SpringMVC执行流程
file:///C:/Users/WANGGA~1/AppData/Local/Temp/enhtmlclip/Image.png
01.拦截所有的请求,访问DispatcherServlet
<ignore_js_op>
02.DispatcherServlet原理是一个Servlet,只要是Servlet就走doService方法
下面是DispatcherServlet的doService方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
protected void doService(HttpServletRequest request, HttpServletResponse response) throws Exception {
   if (logger.isDebugEnabled()) {
      String resumed = WebAsyncUtils.getAsyncManager(request).hasConcurrentResult() ? " resumed" : "";
      logger.debug("DispatcherServlet with name '" + getServletName() + "'" + resumed +
            " processing " + request.getMethod() + " request for [" + getRequestUri(request) + "]");
   }
 
 
   // Keep a snapshot of the request attributes in case of an include,
   // to be able to restore the original attributes after the include.
   Map<String, Object> attributesSnapshot = null;
   if (WebUtils.isIncludeRequest(request)) {
      attributesSnapshot = new HashMap<>();
      Enumeration<?> attrNames = request.getAttributeNames();
      while (attrNames.hasMoreElements()) {
         String attrName = (String) attrNames.nextElement();
         if (this.cleanupAfterInclude || attrName.startsWith(DEFAULT_STRATEGIES_PREFIX)) {
            attributesSnapshot.put(attrName, request.getAttribute(attrName));
         }
      }
   }
 
 
   // Make framework objects available to handlers and view objects.
   request.setAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE, getWebApplicationContext());
   request.setAttribute(LOCALE_RESOLVER_ATTRIBUTE, this.localeResolver);
   request.setAttribute(THEME_RESOLVER_ATTRIBUTE, this.themeResolver);
   request.setAttribute(THEME_SOURCE_ATTRIBUTE, getThemeSource());
 
 
   if (this.flashMapManager != null) {
      FlashMap inputFlashMap = this.flashMapManager.retrieveAndUpdate(request, response);
      if (inputFlashMap != null) {
         request.setAttribute(INPUT_FLASH_MAP_ATTRIBUTE, Collections.unmodifiableMap(inputFlashMap));
      }
      request.setAttribute(OUTPUT_FLASH_MAP_ATTRIBUTE, new FlashMap());
      request.setAttribute(FLASH_MAP_MANAGER_ATTRIBUTE, this.flashMapManager);
   }
 
 
   try {
      doDispatch(request, response);
   }
   finally {
      if (!WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {
         // Restore the original attribute snapshot, in case of an include.
         if (attributesSnapshot != null) {
            restoreAttributesAfterInclude(request, attributesSnapshot);
         }
      }
   }
}

前面都没啥用就是给request添加参数

03.doDispatch(request, response);方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
   HttpServletRequest processedRequest = request;
   HandlerExecutionChain mappedHandler = null;
   boolean multipartRequestParsed = false;
 
 
   WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
 
 
   try {
      ModelAndView mv = null;
      Exception dispatchException = null;
 
 
      try {
         processedRequest = checkMultipart(request);
         multipartRequestParsed = (processedRequest != request);
 
 
         // Determine handler for the current request. 这段代码是用来确定调用方法的,是根据路径解析出来的
         mappedHandler = getHandler(processedRequest);
         if (mappedHandler == null) {
            noHandlerFound(processedRequest, response);
            return;
         }
 
 
         // Determine handler adapter for the current request.
        //确定当前请求程序的适配器 [RequestMappingHandlerAdapter也是就@Controller 的适配器
         HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
 
 
         // Process last-modified header, if supported by the handler.
         String method = request.getMethod();
         boolean isGet = "GET".equals(method);
         if (isGet || "HEAD".equals(method)) {
            long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
            if (logger.isDebugEnabled()) {
               logger.debug("Last-Modified value for [" + getRequestUri(request) + "] is: " + lastModified);
            }
            if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {
               return;
            }
         }
 
 
         if (!mappedHandler.applyPreHandle(processedRequest, response)) {
            return;
         }
 
 
         // Actually invoke the handler.  通过反射调用相应执行的方法
         mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
 
 
         if (asyncManager.isConcurrentHandlingStarted()) {
            return;
         }
 
 
         applyDefaultViewName(processedRequest, mv);
         mappedHandler.applyPostHandle(processedRequest, response, mv);
      }
      catch (Exception ex) {
         dispatchException = ex;
      }
      catch (Throwable err) {
         // As of 4.3, we're processing Errors thrown from handler methods as well,
         // making them available for @ExceptionHandler methods and other scenarios.
         dispatchException = new NestedServletException("Handler dispatch failed", err);
      }
      processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
   }
   catch (Exception ex) {
      triggerAfterCompletion(processedRequest, response, mappedHandler, ex);
   }
   catch (Throwable err) {
      triggerAfterCompletion(processedRequest, response, mappedHandler,
            new NestedServletException("Handler processing failed", err));
   }
   finally {
      if (asyncManager.isConcurrentHandlingStarted()) {
         // Instead of postHandle and afterCompletion
         if (mappedHandler != null) {
            mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);
         }
      }
      else {
         // Clean up any resources used by a multipart request.
         if (multipartRequestParsed) {
            cleanupMultipart(processedRequest);
         }
      }
   }
}

04. mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
此方法主要是调用对应的适配器,然后再通过反射执行对应方法

本来应该调用RequestHandlerAdapter类中的方法,但是没有,根据继承的关系调用父类,抽象类AbstractHandlerMethodAdapter中的方法handle( )

[Java] 纯文本查看 复制代码
1
2
3
4
public final ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
      throws Exception {
   return handleInternal(request, response, (HandlerMethod) handler);
}

本类

[Java] 纯文本查看 复制代码
1
2
protected abstract ModelAndView handleInternal(HttpServletRequest request,HttpServletResponse response,
                                                                         HandlerMethod handlerMethod) throws Exception;

然后在RequestHandlerAdapter中调用 handleInternal( )方法

[Java] 纯文本查看 复制代码
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
protected ModelAndView handleInternal(HttpServletRequest request,
      HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
 
 
   ModelAndView mav;
   checkRequest(request);
 
 
   // Execute invokeHandlerMethod in synchronized block if required.
   if (this.synchronizeOnSession) {
      HttpSession session = request.getSession(false);
      if (session != null) {
         Object mutex = WebUtils.getSessionMutex(session);
         synchronized (mutex) {
            mav = invokeHandlerMethod(request, response, handlerMethod);
         }
      }
      else {
         // No HttpSession available -> no mutex necessary
         mav = invokeHandlerMethod(request, response, handlerMethod);
      }
   }
   else {
      // No synchronization on session demanded at all...
      mav = invokeHandlerMethod(request, response, handlerMethod);
   }

SpringMVC源码剖析1——执行流程的更多相关文章

  1. SpringMVC源码剖析（四）- DispatcherServlet请求转发的实现

    SpringMVC完成初始化流程之后,就进入Servlet标准生命周期的第二个阶段,即“service”阶段.在“service”阶段中,每一次Http请求到来,容器都会启动一个请求线程,通过serv ...

  2. SpringMVC源码剖析（二）- DispatcherServlet的前世今生

    上一篇文章<SpringMVC源码剖析(一)- 从抽象和接口说起>中,我介绍了一次典型的SpringMVC请求处理过程中,相继粉墨登场的各种核心类和接口.我刻意忽略了源码中的处理细节,只列 ...

  3. springmvc源码分析系列-请求处理流程

    接上一篇-springmvc源码分析开头片 上一节主要说了一下springmvc与struts2的作为MVC中的C(controller)控制层的一些区别及两者在作为控制层方面的一些优缺点.今天就结合 ...

  4. SpringMVC源码剖析5：消息转换器HttpMessageConverter与@ResponseBody注解

    转自 SpringMVC关于json.xml自动转换的原理研究[附带源码分析] 本系列文章首发于我的个人博客:https://h2pl.github.io/ 欢迎阅览我的CSDN专栏:Spring源码 ...

  5. SpringMVC源码剖析（五)-消息转换器HttpMessageConverter

    原文链接:https://my.oschina.net/lichhao/blog/172562 #概述 在SpringMVC中,可以使用@RequestBody和@ResponseBody两个注解,分 ...

  6. SpringMVC源码剖析（三）- DispatcherServlet的初始化流程

    在我们第一次学Servlet编程,学Java Web的时候,还没有那么多框架.我们开发一个简单的功能要做的事情很简单,就是继承HttpServlet,根据需要重写一下doGet,doPost方法,跳转 ...

  7. SpringMVC源码剖析（一）- 从抽象和接口说起

    SpringMVC作为Struts2之后异军突起的一个表现层框架,正越来越流行,相信javaee的开发者们就算没使用过SpringMVC,也应该对其略有耳闻.我试图通过对SpringMVC的设计思想和 ...

  8. SpringMVC源码分析-400异常处理流程及解决方法

    本文涉及SpringMVC异常处理体系源码分析,SpringMVC异常处理相关类的设计模式,实际工作中异常处理的实践. 问题场景 假设我们的SpringMVC应用中有如下控制器: 代码示例-1 @Re ...

  9. 【原创】angularjs1.3.0源码解析之执行流程

    Angular执行流程 前言 发现最近angularjs在我厂的应用变得很广泛,下周刚好也有个angular项目要着手开始做,所以先做了下功课,从源代码开始入手会更深刻点,可能讲的没那么细,侧重点在于 ...

随机推荐

  1. MQTT的编译和安装（mosquitto）

    1.基于IBM开发的开元框架实现mosquitto  下载地址:http://mosquitto.org/files/source/ 编译安装:(参考链接:https://www.cnblogs.co ...

  2. jquery 第二节 Dom和jQuery的互相转换

    1.Dom转jQuery Dom对象: var v_dom = document.getElementById("name"); 转换: jQuery对象:    var v_jq ...

  3. 什么？你还没女朋友？教你如何借助Python俘获女孩子芳心！

    天气降温,感情却升温了? 上午刚到公司,就收到小Q发来的灵魂拷问: “Q仔!要不然下午请个假!我带你去精神科看看!?”我实在忍不了,脱口而出. 话音未落,前排的运营小花回头看向小Q,莞尔一笑,百媚横生 ...

  4. mysql not in 或 in 优化

    在MySQL 中,not in 或in 优化思路, 利用left join 来优化,类似如下的查询方式: select id from a where id in (select id from b ...

  5. jsp/servlet编码原理

    转自:http://janwer.iteye.com/blog/150226 首先,说说 JSP/Servlet 中的几个编码的作用 在 JSP/Servlet 中主要有以下几种设置编码的方式: pa ...

  6. SDWebImage缓存图片和读取图片

    NSString *urlStr: NSUrl *url = [NSURL URLWithString:urlStr]; //缓存图片 SDWebImageManager *manager = [SD ...

  7. java 的HashMap底层数据结构

    HashMap也是我们使用非常多的Collection,它是基于哈希表的 Map 接口的实现,以key-value的形式存在.在HashMap中,key-value总是会当做一个整体来处理,系统会根据 ...

  8. 基于serverless快速部署前端项目到腾讯云

    腾讯云 COS 组件,可以快速部署静态网站页面到对象存储 COS 中,并生成域名供访问. 安装 首先要安装 serverless 组件 npm install -g serverless 在项目的根目 ...

  9. 编译x64c++出错，errorC1900：P1和P2之间 Il 不匹配问题

    搜索了下相关资料,有一个说法是编译x64时本地缺失一些东西,2015安装update3就行. 我的是2013update4,找了下最新的有update5,安装然而并没有什么用. 最后还是重新找对应版本 ...

  10. 安装chrome并设置默认主页

    chrome 版本 https://support.google.com/chrome/a/answer/187948?hl=en&ref_topic=2936229