我试图获得一个简单的Websocket,以将其集成到我的应用程序中。但是,在调用处理程序尝试将Tomcat类型转换为javax对象之前,我无法使其与Spring API配合使用,并带有ClassCastException。如果我不使用Spring而直接使用Tomcat(因此使用javax.websocket对象和注释),则它运行良好,因此我真的不确定为什么Spring会有问题。
08-May-2014 01:10:12.048 SEVERE [http-nio-8084-exec-88] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [dispatcher] in context with path [/WebsocketSpringTest] threw exception [Request processing failed; nested exception is org.springframework.web.socket.server.HandshakeFailureException: Uncaught failure for request http://localhost:8084/WebsocketSpringTest/socket; nested exception is java.lang.ClassCastException: org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server.ServerContainer] with root cause java.lang.ClassCastException: org.apache.tomcat.websocket.server.WsServerContainer cannot be cast to javax.websocket.server.ServerContainer at org.springframework.web.socket.server.standard.AbstractStandardUpgradeStrategy.getContainer(AbstractStandardUpgradeStrategy.java:67)
TestSocket.java
import org.springframework.web.socket.WebSocketHandler; public class TestSocket implements WebSocketHandler { ...
web.xml
<servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
dispatcher-servlet.xml
<context:component-scan base-package="com.willnewbery.websocketspringtest" /> <context:annotation-config /> <mvc:annotation-driven /> <mvc:resources mapping="/resources/**" location="/resources/" /> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" p:prefix="/WEB-INF/views/" p:suffix=".jsp" /> <websocket:handlers> <websocket:mapping path="/socket" handler="socket"/> </websocket:handlers> <bean id="socket" class="com.willnewbery.websocketspringtest.TestSocket"/>
pom.xml
<properties> <endorsed.dir>${project.build.directory}/endorsed</endorsed.dir> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <spring.version>4.0.4.RELEASE</spring.version> <tomcat.version>8.0.3</tomcat.version> </properties> <dependencies> <!--javax--> <dependency> <groupId>javax</groupId> <artifactId>javaee-web-api</artifactId> <version>7.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax.websocket</groupId> <artifactId>javax.websocket-api</artifactId> <version>1.0</version> </dependency> <!--spring--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-websocket</artifactId> <version>${spring.version}</version> </dependency> <!--tomcat--> </dependencies>
可能是“ javax.websocket- api”依赖项。它已经包含在服务器库中,因此您至少要将其设置为“提供”范围或尝试将其删除,很有可能您不需要在应用程序pom中使用它。