WebFlux从入门到精通(1)

本是古典何须时尚 2023-06-10 05:19 55阅读 0赞

### WebFlux之HelloWorld ###

`此次开发工具使用idea，jdk11`

1.  打开idea
2.  file -> new -> project 进入下面的界面，使用SpringInitialzr构建一个spirngboot项目  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 1]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 2]
3.  构建出一个基于webflux的项目  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 3]
4.  现在开始编写第一个helloworld  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 4]

package com.example.controller;
    
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class HelloWorldController { 
    
       static final String HELLO_WORLD = "Hello World";
    
       @GetMapping
       public String hello(){ 
           return HELLO_WORLD;
       }
    }

1.  运行这个application  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 5]  
    6.通过查看application启动监听的端口是8080，我们现在通过浏览器访问8080端口  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDEzMDEx_size_16_color_FFFFFF_t_70 6]  
    可以到，helloworld已经成功显示了,但是上面的案例可以看出来，它好像和原来的mvc没什么区别，所以现在我们来改造一下这个项目，将代码修改成下面的样子

package com.example.controller;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.server.reactive.ServerHttpResponse;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    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;
    import reactor.core.publisher.Flux;
    import reactor.core.publisher.Mono;
    
    import java.util.stream.IntStream;
    
    @RestController
    public class HelloWorldController { 
    
        static final String HELLO_WORLD = "Hello World";
    
        @GetMapping
        public String hello(){ 
            return HELLO_WORLD;
        }
    
        /** * 将数据转换成流的方式输出 * Mono是单条数据,Flux一般处理集合或者数组 * @return */
        @GetMapping("/hello1")
        public Mono<String> hello1(){ 
            return Mono.just(HELLO_WORLD);
        }
    
        /** * MediaType.TEXT_EVENT_STREAM_VALUE 设置这个头部是让flux变成响应式的 * 如果不设置这个参数，flux就相当于List Array * @return */
        @GetMapping(value = "/hellon",produces = MediaType.TEXT_EVENT_STREAM_VALUE)
        public Flux<String> hellon(){ 
            return Flux
                    .fromStream(IntStream.range(1,20).mapToObj(item ->HELLO_WORLD + item))
                    .doOnNext(item -> { 
                        try { 
                            //等待500毫秒响应一次数据
                            Thread.sleep(500);
                        } catch (InterruptedException e) { 
                            e.printStackTrace();
                        }
                    });
        }
    
        /** * 定义一个路由函数 * @return */
        @Bean
        public RouterFunction<ServerResponse> function(){ 
            return RouterFunctions.route(
                    RequestPredicates.GET("/helloF"),
                    serverRequest -> { 
                        return ServerResponse.status(HttpStatus.OK).contentType(MediaType.APPLICATION_JSON).bodyValue(HELLO_WORLD);
                    }
            );
        }
    }

通过改造之后，发现webflux有不同方式响应数据，下一次，我会讲webflux如何整合thymeleaf，实现一个登陆注册个功能

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