Java 如何在 tomcat 7 的 Jersey 2 中使用异步回调
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How to use Asynchronous Callbacks in Jersey 2 in tomcat 7
提问by anij
How to use asynchronous callbacks of jersey 2 in tomcat server. I found some examples in Jersey manual : https://jersey.java.net/documentation/latest/user-guide.html#d0e8496.
如何在tomcat服务器中使用jersey 2的异步回调。我在Jersey 手册中找到了一些示例：https: //jersey.java.net/documentation/latest/user-guide.html#d0e8496。
But the issue occurs when I'm tring to test following code with this: https://jersey.java.net/documentation/latest/user-guide.html#d0e8615code as mentioned on Jersey 2 Manual.
但是，当我尝试使用以下代码测试以下代码时会出现问题：https://jersey.java.net/documentation/latest/user-guide.html#d0e8615 代码，如 Jersey 2 手册中所述。
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As, manual version has been changed, I'm posting the codes over here:
由于手动版本已更改，我在此处发布代码：
This is my Service:
这是我的服务：
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.container.AsyncResponse;
import javax.ws.rs.container.CompletionCallback;
import javax.ws.rs.container.Suspended;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
@Path("/resource")
public class AsyncResource {
private static int numberOfSuccessResponses = 0;
private static int numberOfFailures = 0;
private static Throwable lastException = null;
@GET
public void asyncGetWithTimeout(@Suspended final AsyncResponse asyncResponse) {
System.out.println("AsyncResource.asyncGetWithTimeout()");
asyncResponse.register(new CompletionCallback() {
@Override
public void onComplete(Throwable throwable) {
if (throwable == null) {
// no throwable - the processing ended successfully
// (response already written to the client)
numberOfSuccessResponses++;
} else {
numberOfFailures++;
lastException = throwable;
}
}
});
new Thread(new Runnable() {
@Override
public void run() {
String result = veryExpensiveOperation();
asyncResponse.resume(result);
}
private String veryExpensiveOperation() {
// ... very expensive operation
return "Hi";
}
}).start();
}
}
This is client:
这是客户端：
ClientConfig clientConfig = new ClientConfig();
Client client = ClientBuilder.newClient(clientConfig);
WebTarget webTarget = client.target("http://localhost:8080/Jersey2.5Service/rest");
WebTarget target = webTarget.path("resource");
final AsyncInvoker asyncInvoker = target
.request().async();
final Future<Response> responseFuture = asyncInvoker.get();
System.out.println("Request is being processed asynchronously.");
final Response response = responseFuture.get();
// get() waits for the response to be ready
System.out.println("Response received." +response.readEntity(String.class));
web.xml
网页.xml
<servlet>
<servlet-name>HelloServlet</servlet-name>
<servlet-class>
org.glassfish.jersey.servlet.ServletContainer
</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>main.java</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>HelloServlet</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
These are the jars I'm using:
这些是我正在使用的罐子：
asm-all-repackaged-2.2.0-b21.jar
cglib-2.2.0-b21.jar
guava-14.0.1.jar
hk2-api-2.2.0-b21.jar
hk2-locator-2.2.0-b21.jar
hk2-utils-2.2.0-b21.jar
javax.annotation-api-1.2.jar
javax.inject-2.2.0-b21.jar
javax.servlet-api-3.0.1.jar
javax.ws.rs-api-2.0.jar
jaxb-api-2.2.7.jar
jersey-client.jar
jersey-common.jar
jersey-container-servlet-core.jar
jersey-container-servlet.jar
jersey-server.jar
org.osgi.core-4.2.0.jar
osgi-resource-locator-1.0.1.jar
persistence-api-1.0.jar
servlet-api-3.0.jar
validation-api-1.1.0.Final.jar
These errors are coming:
这些错误即将到来：
Jan 31, 2014 4:06:53 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: Not supported.
at org.apache.catalina.connector.Request.startAsync(Request.java:1676)
at org.apache.catalina.connector.RequestFacade.startAsync(RequestFacade.java:1031)
at org.glassfish.jersey.servlet.async.AsyncContextDelegateProviderImpl$ExtensionImpl.suspend(AsyncContextDelegateProviderImpl.java:87)
at org.glassfish.jersey.servlet.internal.ResponseWriter.suspend(ResponseWriter.java:120)
at org.glassfish.jersey.server.ServerRuntime$AsyncResponder.suspend(ServerRuntime.java:758)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:330)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:106)
at org.glassfish.jersey.server.ServerRuntime.run(ServerRuntime.java:259)
at org.glassfish.jersey.internal.Errors.call(Errors.java:271)
at org.glassfish.jersey.internal.Errors.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 org.glassfish.jersey.internal.Errors.process(Errors.java:267)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:318)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:236)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1010)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:373)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:382)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:345)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:220)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Jan 31, 2014 4:06:53 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [HelloServlet] in context with path [/Jersey2.5Service] 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:331)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:106)
at org.glassfish.jersey.server.ServerRuntime.run(ServerRuntime.java:259)
at org.glassfish.jersey.internal.Errors.call(Errors.java:271)
at org.glassfish.jersey.internal.Errors.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 org.glassfish.jersey.internal.Errors.process(Errors.java:267)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:318)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:236)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1010)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:373)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:382)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:345)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:220)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
回答by FelasDroid
For Async callback you can use Guava lib. For example:
对于异步回调，您可以使用 Guava lib。例如：
@GET
@Produces(MediaType.APPLICATION_JSON)
@ManagedAsync
public void getBooks(@Suspended final AsyncResponse response){
ListenableFuture<Collection<Book>> bookFuture = dao.getBooksAsync();
Futures.addCallback(bookFuture, new FutureCallback<Collection<Book>>() {
public void onSuccess(Collection<Book> books){
response.resume(books);
}
public void onFailure(Throwable thrown){
response.resume(thrown);
}
});
}
And in my book DAO I have:
在我的书 DAO 中，我有：
BookDao(){
books = new HashMap<String,Book>();
Book b1 = new Book();
service = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(10));
}
Collection<Book> getBooks(){
return(books.values());
}
ListenableFuture<Collection<Book>> getBooksAsync(){
ListenableFuture<Collection<Book>> future =
service.submit(new Callable<Collection<Book>>() {
public Collection<Book> call() throws Exception{
return getBooks();
}
});
return(future);
}
回答by Aschwin
For me the solution was to add support for Async in a Servlet Filter. The error message gave me a hint:
对我来说，解决方案是在 Servlet 过滤器中添加对异步的支持。错误信息给了我一个提示：
Attempt to put servlet request into asynchronous mode has failed. Please check your servlet configuration - all Servlet instances and Servlet filters involvedin the request processing must explicitly declare support for asynchronous request processing
尝试将 servlet 请求置于异步模式失败。请检查您的 servlet 配置 -请求处理中涉及的所有 Servlet 实例和 Servlet 过滤器必须明确声明对异步请求处理的支持
I am using Spring for Dependency Injection and using the default Jersey servlet. For Spring I use a Delegating Filter Proxy. I needed to declare for the Filter asycn support true.
我使用 Spring 进行依赖注入并使用默认的 Jersey servlet。对于 Spring，我使用委托过滤器代理。我需要声明 Filter asycn 支持为 true。
So for the servlet:
所以对于 servlet：
<servlet>
<servlet-name>myserlet</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<load-on-startup>1</load-on-startup>
<async-supported>true</async-supported>
</servlet>
AND add async support true for the the Spring filter as well.
并为 Spring 过滤器添加异步支持 true。
<filter>
<description>Spring filter</description>
<display-name>spring-filter</display-name>
<filter-name>springFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
<async-supported>true</async-supported>
</filter>
I hope this might help for you and others.
我希望这可能对您和其他人有所帮助。
回答by user3933885
I know this question is very old, but for people who are facing this issue Please update Tomcat Server to the Latest Version 8.** . Tomcat starting from version 8 has support for Async Processing.
我知道这个问题很老了，但是对于遇到这个问题的人，请将 Tomcat 服务器更新到最新版本 8.** 。Tomcat 从版本 8 开始支持异步处理。
回答by Kwesi Aryee
This might be too late, but upgrading to tomcat 9 will resolve this issue, without you modifying anything in the server
这可能为时已晚，但升级到 tomcat 9 将解决此问题，而无需修改服务器中的任何内容
