异步进程在 javax.ws.rs.*（REST 客户端）中不起作用

Question

我在 REST API 中使用 javax（2.26 版本）演示了异步过程。 当我尝试时，我得到“当前链的过滤器或 servlet 不支持异步操作。” 我不知道该怎么办。 我尝试了很多方法，但没有成功。

下面是资源文件Resource.java

import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.container.AsyncResponse;
import javax.ws.rs.container.Suspended;
import javax.ws.rs.core.MediaType;

import com.jersey.rest.User;

@Path("/async")
public class AsynDemo {
    
    @POST
    @Produces(MediaType.APPLICATION_JSON)
    @Consumes(MediaType.APPLICATION_JSON)
    public void asyncMethod(@Suspended final AsyncResponse response, User user) {
        new Thread() {
            public void run() {
                response.resume(true);
            }
        }.start();
    }

}

Pom.xml

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.jersey</groupId>
    <artifactId>rest</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>rest</name>

    <build>
        <finalName>rest</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <inherited>true</inherited>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet</artifactId>
            <!-- use the following artifactId if you don't need servlet 2.x compatibility -->
            <!-- artifactId>jersey-container-servlet</artifactId -->
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.inject</groupId>
            <artifactId>jersey-hk2</artifactId>
            <version>2.26</version>
        </dependency>
        
         <dependency>
             <groupId>javax.activation</groupId>
             <artifactId>activation</artifactId>
             <version>1.1.1</version>
         </dependency>
        <!-- uncomment this to get JSON support-->
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-json-jackson</artifactId>
            </dependency>
        
        <!-- https://mvnrepository.com/artifact/javax.xml.bind/jaxb-api -->
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        
        <dependency> 
           <groupId>com.google.code.gson</groupId> 
           <artifactId>gson</artifactId> 
           <version>2.6.2</version> 
       </dependency>
       
        <dependency>
            <groupId>org.glassfish.jersey.security</groupId>
            <artifactId>oauth2-client</artifactId>
        </dependency>
        
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.10.3</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.11.2</version>
        </dependency>
                
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.11.0</version>
        </dependency>
                
    </dependencies>
    <properties>
        <jersey.version>2.26-b03</jersey.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
</project>

客户端检查 java 文件

import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.MediaType;
import com.jersey.rest.User;

public class MainTesting {
    public static void main(String[] args) {
    
        Client client = ClientBuilder.newClient();
        WebTarget target = client.target("http://localhost:9090/rest/jwt/async"); 
        AsyncInvoker invoker = target.request().async();
        
        Future<Boolean> response = invoker.post(Entity.entity(new User(), MediaType.APPLICATION_JSON), Boolean.class);
        try {
            System.out.println(response.get());
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
        
    }

}

应用程序错误

SEVERE: Servlet.service() for servlet [Jersey jwt Application] in context with path [/rest] threw exception [java.lang.UnsupportedOperationException: Asynchronous processing not supported on Servlet 2.x container.] with root cause
java.lang.UnsupportedOperationException: Asynchronous processing not supported on Servlet 2.x container.
    at org.glassfish.jersey.servlet.WebComponent$3.suspend(WebComponent.java:137)
    at org.glassfish.jersey.servlet.internal.ResponseWriter.suspend(ResponseWriter.java:125)
    at org.glassfish.jersey.server.ServerRuntime$AsyncResponder.suspend(ServerRuntime.java:921)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:326)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:337)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at..................```

Tomcat exception
```WARNING: Unable to start async because the following classes in the processing chain do not support async [org.glassfish.jersey.servlet.ServletContainer]
java.lang.IllegalStateException: A filter or servlet of the current chain does not support asynchronous operations.
    at org.apache.catalina.connector.Request.startAsync(Request.java:1692)
    at org.apache.catalina.connector.RequestFacade.startAsync(RequestFacade.java:1050)
    at org.glassfish.jersey.servlet.async.AsyncContextDelegateProviderImpl$ExtensionImpl.getAsyncContext(AsyncContextDelegateProviderImpl.java:112)
    at org.glassfish.jersey.servlet.async.AsyncContextDelegateProviderImpl$ExtensionImpl.suspend(AsyncContextDelegateProviderImpl.java:96)
    at org.glassfish.jersey.servlet.internal.ResponseWriter.suspend(ResponseWriter.java:125)
    at org.glassfish.jersey.server.ServerRuntime$AsyncResponder.suspend(ServerRuntime.java:921)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:326)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:337)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Err....

Aug 21, 2020 5:07:24 PM org.glassfish.jersey.servlet.internal.ResponseWriter suspend
WARNING: Attempt to put servlet request into asynchronous mode has failed. Please check your servlet configuration - all Servlet instances and Servlet filters involved in the request processing must explicitly declare support for asynchronous request processing.
java.lang.IllegalStateException: A filter or servlet of the current chain does not support asynchronous operations.
    at org.apache.catalina.connector.Request.startAsync(Request.java:1692)
    at org.apache.catalina.connector.RequestFacade.startAsync(RequestFacade.java:1050)
    at org.glassfish.jersey.servlet.async.AsyncContextDelegateProviderImpl$ExtensionImpl.getAsyncContext(AsyncContextDelegateProviderImpl.java:112)
    at org.glassfish.jersey.servlet.async.AsyncContextDelegateProviderImpl$ExtensionImpl.suspend(AsyncContextDelegateProviderImpl.java:96)
    at org.glassfish.jersey.servlet.internal.ResponseWriter.suspend(ResponseWriter.java:125)
    at org.glassfish.jersey.server.ServerRuntime$AsyncResponder.suspend(ServerRuntime.java:921)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:326)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    at org.glassfish.jersey.server.Serv.....

Aug 21, 2020 5:07:24 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Jersey jwt Application] in context with path [/rest] threw exception [javax.ws.rs.ProcessingException: Attempt to suspend a connection of an asynchronous request failed in the underlying container.] with root cause
javax.ws.rs.ProcessingException: Attempt to suspend a connection of an asynchronous request failed in the underlying container.
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:327)
    at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:337)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    ....```

Could you help me to solve this? :)

Answer 1

在 web.xml servlet 定义中添加<async-supported>true</async-supported> 。

<servlet>
    <servlet-name>Jersey jwt Application</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>com.jersey.jwt</param-value>
    </init-param>
    <async-supported>true</async-supported>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>Jersey jwt Application</servlet-name>
    <url-pattern>/jwt/*</url-pattern>
</servlet-mapping>

它解决了这个问题。