From 632324d94b4cc8ef0e5256a47455efe6d5e0a1fb Mon Sep 17 00:00:00 2001
From: Rikako Wu <496063163@qq.com>
Date: Wed, 30 Nov 2022 23:51:11 +0800
Subject: [PATCH] =?UTF-8?q?=E6=97=A5=E5=B8=B8=E6=8F=90=E4=BA=A4?=
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---
 spring/Spring core/SpringMVC.md | 39 +++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/spring/Spring core/SpringMVC.md b/spring/Spring core/SpringMVC.md
index a1897ed..c06042c 100644
--- a/spring/Spring core/SpringMVC.md	
+++ b/spring/Spring core/SpringMVC.md	
@@ -356,8 +356,43 @@ public String handle(@SessionAttribute User user) {
 }
 ```
 #### Multipart
-在MultipartResolver被启用之后，
-
+在MultipartResolver被启用之后，Post请求体中为multipart/form-data格式的数据将被转化并可以作为handler method的参数访问。如下显示了文件上传的用法：
+```java
+@Controller
+public class FileUploadController {
+
+    @PostMapping("/form")
+    public String handleFormUpload(@RequestParam("name") String name,
+            @RequestParam("file") MultipartFile file) {
+
+        if (!file.isEmpty()) {
+            byte[] bytes = file.getBytes();
+            // store the bytes somewhere
+            return "redirect:uploadSuccess";
+        }
+        return "redirect:uploadFailure";
+    }
+}
+```
+> 在上述代码中，可以将MultipartFile改为List\<MultipartFile\>来解析多个文件名  
+> **当@RequestParam没有指定name属性并且参数类型为Map<String,MultipartFile>或MultiValueMap<String,MultipartFile>类型时，会根据name自动将所有匹配的MultipartFile注入到map中**
+
+#### @RequestBody
+可以通过@RequestBody注解读取请求体内容，并且通过HttpMessageConverter将内容反序列化为Object。具体使用方法如下：
+```java
+@PostMapping("/accounts")
+public void handle(@RequestBody Account account) {
+    // ...
+}
+```
+#### HttpEntity
+将参数类型指定为HttpEntity与使用@RequestBody注解类似，其作为一个容器包含了请求体转化后的对象（account实例）和请求头（HttpHeaders）。其使用如下：
+```java
+@PostMapping("/accounts")
+public void handle(HttpEntity<Account> entity) {
+    // ...
+}
+```