在工作的时候，准备使用websocker建立长连接来统计网站在线人数，但是在配置好所有东西后，发现springboot启动失败
详细错误
java.lang.IllegalStateException: Failed to register @ServerEndpoint class: class com.example.pipayshopapi.component.WebSocketServer
at org.springframework.web.socket.server.standard.ServerEndpointExporter.registerEndpoint(ServerEndpointExporter.java:159) ~[spring-websocket-5.3.3.jar:5.3.3]
at org.springframework.web.socket.server.standard.ServerEndpointExporter.registerEndpoints(ServerEndpointExporter.java:134) ~[spring-websocket-5.3.3.jar:5.3.3]
at org.springframework.web.socket.server.standard.ServerEndpointExporter.afterSingletonsInstantiated(ServerEndpointExporter.java:112) ~[spring-websocket-5.3.3.jar:5.3.3]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:963) ~[spring-beans-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:923) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:588) ~[spring-context-5.3.3.jar:5.3.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1311) [spring-boot-2.4.2.jar:2.4.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) [spring-boot-2.4.2.jar:2.4.2]
at com.example.pipayshopapi.PipayshopApiApplication.main(PipayshopApiApplication.java:16) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_382]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_382]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_382]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_382]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.4.2.jar:2.4.2]
Caused by: javax.websocket.DeploymentException: No payload parameter present on the method [onMessage] of class [com.example.pipayshopapi.component.WebSocketServer] that was annotated with OnMessage
at org.apache.tomcat.websocket.pojo.PojoMethodMapping$MessageHandlerInfo.<init>(PojoMethodMapping.java:567) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.pojo.PojoMethodMapping.<init>(PojoMethodMapping.java:139) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.server.WsServerContainer.addEndpoint(WsServerContainer.java:154) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.server.WsServerContainer.addEndpoint(WsServerContainer.java:278) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.apache.tomcat.websocket.server.WsServerContainer.addEndpoint(WsServerContainer.java:228) ~[tomcat-embed-websocket-9.0.41.jar:9.0.41]
at org.springframework.web.socket.server.standard.ServerEndpointExporter.registerEndpoint(ServerEndpointExporter.java:156) ~[spring-websocket-5.3.3.jar:5.3.3]
... 18 common frames omitted在网上查了一番资料后，
1.有的说是aop导致的，
2.有的说是@ServerEndpoint 注解中配置路径必须以"/" 开头，
3.有的说的是SpringBoot内置Tomcat，使用ServerEndpointExporter扫描注册ServerEndpoint，而测试服务器的容器是Tomcat，使用自带jar包中的ServerApplicationConfig扫描注册ServerEndpoint，不同的容器使用不同的扫描机制
第一种，我没有配置aop所以不是这原因，pass。
第二种我有配置以"/"开头，pass
第三种，我没有试过，所以去试了一下：
在websockerconfig中加@ConditionalOnProperty(name = "spring.profiles.active", havingValue = "dev")注解
@Configuration
@ConditionalOnProperty(name = "spring.profiles.active", havingValue = "dev")
public class WebSocketConfig {
/**
* 注入一个ServerEndpointExporter,该Bean会自动注册使用@ServerEndpoint注解申明的websocket endpoint
*/
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}在websockerservce中加@ConditionalOnClass(value = WebSocketConfig.class)注解
@ServerEndpoint(value = "/dailyActive/{userId}")
@Component
@ConditionalOnClass(value = WebSocketConfig.class)
public class WebSocketServer {
private static final Logger log = LoggerFactory.getLogger(WebSocketServer.class);
// 注入查看聊天列表的服务
/**
* 记录当前在线连接数
*/
public static final Map<String, Session> dailyActiveCount = new ConcurrentHashMap<>();
public static final String dailyActiveName="dailyActiveName";
// @Resource
// private StringRedisTemplate stringRedisTemplate;
/**
* 连接建立成功调用的方法
*/
@OnOpen
public void onOpen(Session session, @PathParam("userId") String userId) {
log.error(userId+"----------------------------------------------进入");
// 保存当前用户session
dailyActiveCount.put(userId, session);
// 存入redis中去
// stringRedisTemplate.opsForValue().set(dailyActiveName,String.valueOf(dailyActiveCount.size()));
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose(Session session, @PathParam("userId") String userId) {
log.error(userId+"----------------------------------------------关闭");
// 移除当前用户session
dailyActiveCount.remove(userId);
// 存入redis中去
// stringRedisTemplate.opsForValue().set(dailyActiveName,String.valueOf(dailyActiveCount.size()));
}
/**
* 收到客户端消息后调用的方法
* 后台收到客户端发送过来的消息
* onMessage 是一个消息的中转站
* 接受 浏览器端 socket.send 发送过来的 json数据
*/
@OnMessage
public void onMessage(Session session, @PathParam("userId") String userId) {
}
@OnError
public void onError(Session session, Throwable error) {
log.error("发生错误");
error.printStackTrace();
}
}加了之后启动类，确实能启动了，我欣喜若狂，以为找到答案了
但是在页面尝试连接websocker的时候，当场给我泼了一盆冷水
在网上搜了一波：
有的说是server.servlet.context-path，可是我已经写上去了，pass。
其他都没有用，最后我在走投无路之下，去垃圾桶找回我以前能运行websocker的项目，在两个对比之下，原来是在@OnMessage方法少了一个参数 ，我猜想可能这个方法需要接收三个参数
顺序无所谓
都是能启动的
连接成功
详细的websockerconfig和websockerservice代码
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
@Configuration
public class WebSocketConfig {
/**
* 注入一个ServerEndpointExporter,该Bean会自动注册使用@ServerEndpoint注解申明的websocket endpoint
*/
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}
}import com.example.pipayshopapi.config.WebSocketConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;
import javax.annotation.Resource;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* @author websocket服务
*/
@ServerEndpoint(value = "/dailyActive/{userId}")
@Component
public class WebSocketServer {
private static final Logger log = LoggerFactory.getLogger(WebSocketServer.class);
// 注入查看聊天列表的服务
/**
* 记录当前在线连接数
*/
public static final Map<String, Session> dailyActiveCount = new ConcurrentHashMap<>();
public static final String dailyActiveName="dailyActiveName";
// @Resource
// private StringRedisTemplate stringRedisTemplate;
/**
* 连接建立成功调用的方法
*/
@OnOpen
public void onOpen(Session session, @PathParam("userId") String userId) {
log.error(userId+"----------------------------------------------进入");
// 保存当前用户session
dailyActiveCount.put(userId, session);
// 存入redis中去
// stringRedisTemplate.opsForValue().set(dailyActiveName,String.valueOf(dailyActiveCount.size()));
}
/**
* 连接关闭调用的方法
*/
@OnClose
public void onClose(Session session, @PathParam("userId") String userId) {
log.error(userId+"----------------------------------------------关闭");
// 移除当前用户session
dailyActiveCount.remove(userId);
// 存入redis中去
// stringRedisTemplate.opsForValue().set(dailyActiveName,String.valueOf(dailyActiveCount.size()));
}
/**
* 收到客户端消息后调用的方法
* 后台收到客户端发送过来的消息
* onMessage 是一个消息的中转站
* 接受 浏览器端 socket.send 发送过来的 json数据
*/
@OnMessage
public void onMessage(Session session, String message,@PathParam("userId") String userId) {
}
@OnError
public void onError(Session session, Throwable error) {
log.error("发生错误");
error.printStackTrace();
}
}
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