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. Linux下idea由于缺少相关权限导致的tomcat ERROR

    昨天一天都在倒腾两个系统,也是醉了. 不过还好,系统修好了,在ubuntu下重新安装idea后,出现了这个错误: Intellij Idea Tmocat Error running Tomcat: ...

  2. Python笔记_第四篇_高阶编程_进程、线程、协程_5.GPU加速

    Numba:高性能计算的高生产率 在这篇文章中,笔者将向你介绍一个来自Anaconda的Python编译器Numba,它可以在CUDA-capable GPU或多核cpu上编译Python代码.Pyt ...

  3. Java中static变量作用和用法详解

    static表示"全局"或者"静态"的意思,用来修饰成员变量和成员方法,也可以形成静态static代码块,但是Java语言中没有全局变量的概念. 被static ...

  4. UVALive 2678 利用序列的前缀来减少时间复杂度

    题意很简单,在一串正整数序列中找一个连续的子序列使该序列和大于等于一个已知量S,但要求序列长度最短,通常喜欢暴力枚举 这个题目跟大白书之前的一个题目很像,在数列A中 求 Ai-Aj最大 并且 i< ...

  5. PAT Vocabulary

    数字 单词 词性 中文意 常用 音标 non-negative 非负数 non-negative number Positive 正整数 Positive integer Negative 负数 Ne ...

  6. druid socket timeout超时15分钟(转载)

    背景 在应用端通过mybatis的interceptor自定义Plugin拦截Executor, 统计输出sql的执行耗时. 今天生产发生一个很奇怪的问题: 莫名其妙卡顿15分钟+,其后正常返回sql ...

  7. 第二季 第十一天 part2

    const greeting = function() { // 注意,这个 this.name 取决于谁调用了 greeting() 函数 console.log('Hi, ', this.name ...

  8. 编程基础-servlet1

    1.Servelet是什么 sevlet是Server与Applet 的缩写,即服务端小程序.Sun公司提供的开发动态web资源的技术. servelet本质是java类,但遵循Servlet规范,没 ...

  9. 量化投资_关于Multicharts砖型图(传统砖型图和非传统砖型图)最详细的解释_调用篇

    1. 砖图形成数组后,我们再对他们复制到数组中然后再调用出来看一下. 2. 如下是累计只取20个数组大小为例,如果开始阶段数组长度组成初始的Array[20]的长度,然后这个数组的最后一个值填满后,进 ...

  10. LCA 最近公共祖先 Tarjan(离线)算法的基本思路及其算法实现

    首先是最近公共祖先的概念(什么是最近公共祖先?): 在一棵没有环的树上,每个节点肯定有其父亲节点和祖先节点,而最近公共祖先,就是两个节点在这棵树上深度最大的公共的祖先节点. 换句话说,就是两个点在这棵 ...