阅读webflux文档

spring/webflux/spring webflux.md

@@ -37,6 +37,10 @@
     - [Overview](#overview)
     - [Immutable](#immutable)
     - [Router Function](#router-function)
+    - [HandlerFunction](#handlerfunction)
+    - [Server Request](#server-request)
+    - [ServerResponse](#serverresponse)
+    - [Handler Class](#handler-class)
 
 
 # Spring Webflux
@@ -542,4 +546,90 @@ public class PersonHandler {
 - `RouterFunctions.toHttpHandler(RouterFunction)`
 - `RouterFunctions.toHttpHandler(RouterFunction, HandlerStrategies)`
 
+### HandlerFunction
+`ServerRequest`和`ServerResponse`为不可变接口，两者都对body stream提供Reactive Stream back pressure。
+- 其中，request body通过Reactor `Flux`或`Mono`表示
+- response body可以通过任何`Reactive Stream Publisher`进行表示，包括`Flux`和`Mono`
+
+### Server Request
+ServerRequest提供了对如下内容的访问：
+- http method 
+- uri 
+- headers
+- query params 
+- body
+
+如下示例展示了如何将请求体转化为`Mono/Flux`类型：
+```java
+Mono<String> string = request.bodyToMono(String.class);
+
+Flux<Person> people = request.bodyToFlux(Person.class);
+```
+
+如下示例展示了如何访问formdata:
+```java
+Mono<MultiValueMap<String, String>> map = request.formData();
+```
+
+如下示例展示了如何访问multipart data：
+```java
+Mono<MultiValueMap<String, Part>> map = request.multipartData();
+```
+
+访问multipart数据内容的示例如下所示:
+```java
+Flux<PartEvent> allPartEvents = request.bodyToFlux(PartEvent.class);
+allPartsEvents.windowUntil(PartEvent::isLast)
+      .concatMap(p -> p.switchOnFirst((signal, partEvents) -> {
+          if (signal.hasValue()) {
+              PartEvent event = signal.get();
+              if (event instanceof FormPartEvent formEvent) {
+                  String value = formEvent.value();
+                  // handle form field
+              }
+              else if (event instanceof FilePartEvent fileEvent) {
+                  String filename = fileEvent.filename();
+                  Flux<DataBuffer> contents = partEvents.map(PartEvent::content);
+                  // handle file upload
+              }
+              else {
+                  return Mono.error(new RuntimeException("Unexpected event: " + event));
+              }
+          }
+          else {
+              return partEvents; // either complete or error signal
+          }
+      }));
+```
+### ServerResponse 
+ServerResponse类提供了对http返回内容的访问，由于ServerResponse是不可变的，故而可以通过`build`方法来创建ServerResponse。
+
+如下示例展示了ServerResponse的使用
+```java
+Mono<Person> person = ...
+ServerResponse.ok().contentType(MediaType.APPLICATION_JSON).body(person, Person.class);
+
+URI location = ...
+ServerResponse.created(location).build();
+```
+
+同时，在构建响应体时，支持传递hint参数来控制body被序列化和反序列化的方式，示例如下：
+```java
+ServerResponse.ok().hint(Jackson2CodecSupport.JSON_VIEW_HINT, MyJacksonView.class).body(...);
+```
+
+### Handler Class
+可以将HandlerFunction写为lambda的形式，示例如下：
+```java
+HandlerFunction<ServerResponse> helloWorld =
+  request -> ServerResponse.ok().bodyValue("Hello World");
+```
+
+
+
+
+
+
+
+