SpringBoot2使用WebFlux函數式編程
阿新 • • 發佈：2018-07-31
output 源碼下載 learn efault perm rest tpm apach cat
本文只是簡單使用SpringBoot2使用WebFlux的函數式編程簡單使用，後續會繼續寫關於Webflux相關的文章。
最近一直在研究WebFlux，後續會陸續出一些相關的文章。
首先看一下Srping官網上的一張圖，對比一下SpringMvc和Spring WebFlux，如圖：
在查看一下WebFlux的官方文檔:https://docs.spring.io/spring/docs/current/spring-framework-reference/web-reactive.html#spring-webflux，WebFlux提供了函數式編程，本文簡單介紹一下WebFlux函數式編程簡單使用。
新建項目
創建一個項目，pom文件中引入webflux依賴，完整pom文件如下：
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.dalaoyang</groupId> <artifactId>springboot2_webflux</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot2_webflux</name> <description>springboot2_webflux</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.3.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-webflux</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
首先試試引入WebFlux依賴之後，SpringMvc方式是否還能使用，新建一個HelloController，完整代碼如下，執行後發現，是可以正常執行訪問的，這其實就是我們所說的註解式編程。
package com.dalaoyang.controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; /** * @author dalaoyang * @project springboot_learn * @package com.dalaoyang.controller * @email [email protected] * @date 2018/7/30 */ @RestController public class HelloController { @GetMapping("hello") public String Hello(){ return "Hello this is SpringWebFlux"; } }
結果如圖：
接下來使用函數式編程，首先查閱一下官方文檔，如圖：
我們需要創建一個HandlerFunction返回值為Mono，新建一個HiHandler，裏面寫一個方法Hi，完整代碼如下：
package com.dalaoyang.handler;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;
/**
* @author dalaoyang
* @project springboot_learn
* @package com.dalaoyang.handler
* @email [email protected]
* @date 2018/7/30
*/
@Component
public class HiHandler {
public Mono<ServerResponse> Hi(ServerRequest request) {
return ServerResponse.ok().contentType(MediaType.APPLICATION_JSON)
.body(BodyInserters.fromObject("Hi , this is SpringWebFlux"));
}
}其中ServerResponse是相應的封裝對象，下面是它的源碼，其中包含了響應狀態，響應頭等等，代碼如下：
package org.springframework.web.reactive.function.server;
import java.net.URI;
import java.time.ZonedDateTime;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiFunction;
import java.util.function.Consumer;
import org.reactivestreams.Publisher;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.CacheControl;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseCookie;
import org.springframework.http.codec.HttpMessageWriter;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.util.MultiValueMap;
import org.springframework.web.reactive.function.BodyInserter;
import org.springframework.web.reactive.result.view.ViewResolver;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
public interface ServerResponse {
HttpStatus statusCode();
HttpHeaders headers();
MultiValueMap<String, ResponseCookie> cookies();
Mono<Void> writeTo(ServerWebExchange var1, ServerResponse.Context var2);
static ServerResponse.BodyBuilder from(ServerResponse other) {
return new DefaultServerResponseBuilder(other);
}
static ServerResponse.BodyBuilder status(HttpStatus status) {
return new DefaultServerResponseBuilder(status);
}
static ServerResponse.BodyBuilder status(int status) {
return new DefaultServerResponseBuilder(status);
}
static ServerResponse.BodyBuilder ok() {
return status(HttpStatus.OK);
}
static ServerResponse.BodyBuilder created(URI location) {
ServerResponse.BodyBuilder builder = status(HttpStatus.CREATED);
return (ServerResponse.BodyBuilder)builder.location(location);
}
static ServerResponse.BodyBuilder accepted() {
return status(HttpStatus.ACCEPTED);
}
static ServerResponse.HeadersBuilder<?> noContent() {
return status(HttpStatus.NO_CONTENT);
}
static ServerResponse.BodyBuilder seeOther(URI location) {
ServerResponse.BodyBuilder builder = status(HttpStatus.SEE_OTHER);
return (ServerResponse.BodyBuilder)builder.location(location);
}
static ServerResponse.BodyBuilder temporaryRedirect(URI location) {
ServerResponse.BodyBuilder builder = status(HttpStatus.TEMPORARY_REDIRECT);
return (ServerResponse.BodyBuilder)builder.location(location);
}
static ServerResponse.BodyBuilder permanentRedirect(URI location) {
ServerResponse.BodyBuilder builder = status(HttpStatus.PERMANENT_REDIRECT);
return (ServerResponse.BodyBuilder)builder.location(location);
}
static ServerResponse.BodyBuilder badRequest() {
return status(HttpStatus.BAD_REQUEST);
}
static ServerResponse.HeadersBuilder<?> notFound() {
return status(HttpStatus.NOT_FOUND);
}
static ServerResponse.BodyBuilder unprocessableEntity() {
return status(HttpStatus.UNPROCESSABLE_ENTITY);
}
public interface Context {
List<HttpMessageWriter<?>> messageWriters();
List<ViewResolver> viewResolvers();
}
public interface BodyBuilder extends ServerResponse.HeadersBuilder<ServerResponse.BodyBuilder> {
ServerResponse.BodyBuilder contentLength(long var1);
ServerResponse.BodyBuilder contentType(MediaType var1);
ServerResponse.BodyBuilder hint(String var1, Object var2);
<T, P extends Publisher<T>> Mono<ServerResponse> body(P var1, Class<T> var2);
<T, P extends Publisher<T>> Mono<ServerResponse> body(P var1, ParameterizedTypeReference<T> var2);
Mono<ServerResponse> syncBody(Object var1);
Mono<ServerResponse> body(BodyInserter<?, ? super ServerHttpResponse> var1);
Mono<ServerResponse> render(String var1, Object... var2);
Mono<ServerResponse> render(String var1, Map<String, ?> var2);
}
public interface HeadersBuilder<B extends ServerResponse.HeadersBuilder<B>> {
B header(String var1, String... var2);
B headers(Consumer<HttpHeaders> var1);
B cookie(ResponseCookie var1);
B cookies(Consumer<MultiValueMap<String, ResponseCookie>> var1);
B allow(HttpMethod... var1);
B allow(Set<HttpMethod> var1);
B eTag(String var1);
B lastModified(ZonedDateTime var1);
B location(URI var1);
B cacheControl(CacheControl var1);
B varyBy(String... var1);
Mono<ServerResponse> build();
Mono<ServerResponse> build(Publisher<Void> var1);
Mono<ServerResponse> build(BiFunction<ServerWebExchange, ServerResponse.Context, Mono<Void>> var1);
}
}在回過頭了看上面官方文檔的圖片，還需要配置一個路由來類似@RequestMapping的功能，通過RouterFunctions.route(RequestPredicate, HandlerFunction)提供了一個路由器函數默認實現，新建一個HiRouter，代碼如下：
package com.dalaoyang.router;
import com.dalaoyang.handler.HiHandler;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.server.RequestPredicates;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.RouterFunctions;
import org.springframework.web.reactive.function.server.ServerResponse;
/**
* @author dalaoyang
* @project springboot_learn
* @package com.dalaoyang.router
* @email [email protected]
* @date 2018/7/30
*/
@Configuration
public class HiRouter {
@Bean
public RouterFunction<ServerResponse> routeCity(HiHandler hiHandler) {
return RouterFunctions
.route(RequestPredicates.GET("/hi")
.and(RequestPredicates.accept(MediaType.APPLICATION_JSON)),
hiHandler::Hi);
}
}啟動項目，通過控制臺可以看到，兩種方式的映射都被打印出來了，如圖所示：
在瀏覽器訪問，http://localhost:8080/hi,結果如圖所示:
源碼下載 ：大老楊碼雲
個人網站：https://www.dalaoyang.cn
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SpringBoot2使用WebFlux函數式編程