【问题标题】:Spring boot WebSocket connection to 'ws://127.0.0.1:8081/getUsersList/' failed: Error during WebSocket handshake: Unexpected response code: 200Spring Boot WebSocket 连接到“ws://127.0.0.1:8081/getUsersList/”失败:WebSocket 握手期间出错:意外响应代码:200
【发布时间】:2020-04-03 17:35:03
【问题描述】:

我的下面的客户端抛出了下面的异常。

我也试过localhost

到“ws://127.0.0.1:8081/getUsersList/”的 WebSocket 连接失败: WebSocket 握手期间出错:意外响应代码:200

当我尝试点击浏览器时,它会按预期流式传输数据,但是当我尝试从 Javascript 客户端获取数据时,它会导致问题。

http://127.0.0.1:8081/getUsersList

data:19:20:33
data:

data:19:20:34
data:

data:19:20:36
data:

data:19:20:37

我认为作为端口映射的一部分遗漏了一些东西,所以如果有人可以帮助解决这个问题,那将是可观的。

提前致谢!

代码:

index.html - 客户端

      <script type = "text/javascript">
         function WebSocketTest() {

            if ("WebSocket" in window) {
               alert("WebSocket is supported by your Browser!");

               // Let us open a web socket
               var ws = new WebSocket("ws://127.0.0.1:8081/getUsersList/");

               ws.onopen = function() {

                  // Web Socket is connected, send data using send()
                  //ws.send("Message to send");
                //  alert("Message is sent...");
               };

               ws.onmessage = function (evt) { 
                  var received_msg = evt.data;
                  alert("Message is received...");
               };

               ws.onclose = function() { 

                  // websocket is closed.
                  alert("Connection is closed..."); 
               };
            } else {

               // The browser doesn't support WebSocket
               alert("WebSocket NOT supported by your Browser!");
            }
        }
      </script>

   </head>

   <body>
      <div id = "sse">
         <a href = "javascript:WebSocketTest()">Run WebSocket</a>
      </div>

   </body>
</html>

pom.xml

<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>Webflux-POC</groupId>
    <artifactId>Webflux-POC</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Webflux-POC</name>
    <description>POC on webflux</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>


        <dependency>
            <groupId>com.jcraft</groupId>
            <artifactId>jsch</artifactId>
            <version>0.1.54</version>
        </dependency>

        <dependency>
            <groupId>net.logstash.logback</groupId>
            <artifactId>logstash-logback-encoder</artifactId>
            <version>4.9</version>
        </dependency>


        <!-- https://mvnrepository.com/artifact/javax.websocket/javax.websocket-api -->
        <dependency>
            <groupId>javax.websocket</groupId>
            <artifactId>javax.websocket-api</artifactId>
            <version>1.1</version>
            <scope>provided</scope>
        </dependency>


    </dependencies>


    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

WebfluxApp.java

package com.poc.webflux;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.reactive.config.EnableWebFlux;

@SpringBootApplication
@EnableWebFlux
@ComponentScan
public class WebfluxApp {
    public static void main(String[] args) {
        SpringApplication.run(WebfluxApp.class);
    }
}

UsersController.java

package com.poc.webflux;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.poc.webflux.service.UserService;

import reactor.core.publisher.Flux;

@RestController
@CrossOrigin
public class UsersController {

    @Autowired
    private UserService userService;

    @GetMapping(value="/getUsersList",produces = "text/event-stream")
    public Flux<String> getUsersList(){
        return userService.getUsersList();
    }

}

用户服务.java

package com.poc.webflux.service;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.Objects;
import java.util.stream.Stream;

import org.springframework.stereotype.Service;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;

import reactor.core.publisher.Flux;

@Service
public class UserService {

    public Flux<String> getUsersList() {
        return Flux.fromStream(Stream.generate(() -> {
             String str = getRandomNumber();
             System.out.println(str);
             return str ;
        }))
                //.log()
                .delayElements(Duration.ofSeconds(1));

    }

    private String getRandomString() {
        return "Test";
    }
}

【问题讨论】:

    标签: javascript java spring-boot websocket spring-webflux


    【解决方案1】:

    您正在尝试在 http 端点建立 websocket 连接。要在响应式堆栈上公开 websocket 连接端点,您需要实现 WebSocketHandler 并向端点和实现的 WebSocketHandler 提供 HandlerMapping。

    在简历中: 1 - 创建一个实现 WebSocketHandler 的类,并使您在处理方法上的业务逻辑实现(在您的情况下是用户服务的逻辑)。 2 - 创建一个@Configuration,它公开一个 HandlerMapping bean,其中包含您要建立 websocket 连接的端点和您的 WebSocketHandler 实现。

    有关响应式 websocket 实现的更多详细信息,请参阅official documentation

    【讨论】:

    • 谢谢。看看,我是 websocket 的新手,所以你的意思是说我们不应该有 @RestController ,而是应该有 Handler 代替控制器?
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