为什么我得到多个客户端:当只有一个客户端连接时，来自cometd的真实建议

Question

我正在将CometD集成到Grails 2.0应用程序中（通过创建一个新的插件-我没有使用现有的CometD插件，因为它现在似乎很破碎）。我相信我已经把所有东西都配置好了。我所经历的是，当浏览器连接时，最初的元/握手会成功返回。然而，此后的每个meta/connect调用都会返回针对多个客户端的建议，并将其设置为true，从而关闭长轮询连接。然后每2秒发生一次（我认为这是默认的间隔）。

正如我所说，我使用的是Grails 2.0，其中tomcat 7是Grails默认使用的。

以下是我目前看到的：

呼叫/元/握手

Request URL:http://localhost:8080/cometd/handshake
Request Method:POST
Status Code:200 OK
Request Headers
Accept:*/*
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Content-Length:182
Content-Type:application/json;charset=UTF-8
Host:localhost:8080
Origin:http://localhost:8080
Referer:http://localhost:8080/
User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.46 Safari/535.11
X-Requested-With:XMLHttpRequest
Request Payload
[{"version":"1.0","minimumVersion":"0.9","channel":"/meta/handshake","supportedConnectionTypes":["long-polling","callback-polling"],"advice":{"timeout":60000,"interval":0},"id":"1"}]
Response Headers
Content-Length:201
Content-Type:application/json;charset=UTF-8
Date:Tue, 14 Feb 2012 03:32:24 GMT
Server:Apache-Coyote/1.1
Set-Cookie:BAYEUX_BROWSER=dac8yl3vlli7s8x2gymdm2ca177s; Path=/

这是返回的有效载荷：

[{"id":"1","minimumVersion":"1.0","supportedConnectionTypes":["callback-polling","long-polling"],"successful":true,"channel":"/meta/handshake","clientId":"115v93y19uvavr159qvzz43yct1","version":"1.0"}]

我已经验证了正在浏览器中设置cookie。随后对/meta/connect的调用如下所示：

Request URL:http://localhost:8080/cometd/connect
Request Method:POST
Status Code:200 OK
Request Headers
Accept:*/*
Accept-Charset:ISO-8859-1,utf-8;q=0.7,*;q=0.3
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Content-Length:134
Content-Type:application/json;charset=UTF-8
Cookie:BAYEUX_BROWSER=dac8yl3vlli7s8x2gymdm2ca177s
Host:localhost:8080
Origin:http://localhost:8080
Referer:http://localhost:8080/
User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.46 Safari/535.11
X-Requested-With:XMLHttpRequest
Request Payload
[{"channel":"/meta/connect","connectionType":"long-polling","advice":{"timeout":0},"id":"2","clientId":"115v93y19uvavr159qvzz43yct1"}]
Response Headers
Content-Length:116
Content-Type:application/json;charset=UTF-8
Date:Tue, 14 Feb 2012 03:32:24 GMT
Server:Apache-Coyote/1.1

其中请求有效载荷中的内容长度和id根据每个请求而改变。前3个电话的回复是：

呼叫1:

[{"id":"2","successful":true,"advice":{"interval":0,"reconnect":"retry","timeout":30000},"channel":"/meta/connect"}]

呼叫2:

[{"id":"3","successful":true,"channel":"/meta/connect"}]

呼叫3:

[{"id":"4","successful":true,"advice":{"interval":2000,"reconnect":"retry","multiple-clients":true},"channel":"/meta/connect"}]

从那时起，每一条返回的信息都与上一条完全相同。我只打开了一个浏览器窗口/选项卡。

以下是web.xml文件的适用部分的副本：

<web-app xmlns="http://java.sun.com/xml/ns/javaee" version="3.0" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
...
<servlet>
    <servlet-name>cometd</servlet-name>
    <servlet-class>org.cometd.server.CometdServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
    <init-param>
        <param-name>timeout</param-name>
        <param-value>30000</param-value>
    </init-param>
    <init-param>
        <param-name>logLevel</param-name>
        <param-value>3</param-value>
    </init-param>
</servlet>
...
<servlet-name>cometd</servlet-name>
    <url-pattern>/cometd/*</url-pattern>
</servlet-mapping>
...
</web-app>

BuildConfig.groovy:

grails.project.class.dir = "target/classes"
grails.project.test.class.dir = "target/test-classes"
grails.project.test.reports.dir = "target/test-reports"
grails.project.target.level = 1.6
grails.project.dependency.resolution = {
    // inherit Grails' default dependencies
    inherits "global"
    log "warn" // log level of Ivy resolver, either 'error', 'warn', 'info', 'debug' or 'verbose'
    repositories {
        mavenCentral()
    }
    dependencies {
        def cometVersion = '2.4.0'
        compile(group: 'org.cometd.java', name: 'cometd-java-server', version: cometVersion) {
            excludes 'servlet-api'
        }
        compile group: 'org.cometd.java', name: 'bayeux-api', version: cometVersion
        runtime group: 'org.eclipse.jetty', name: 'jetty-servlets', version: '7.6.0.v20120127'
        test group: 'org.cometd.java', name: 'cometd-java-client', version: cometVersion        
    }
    plugins {
        build(":tomcat:$grailsVersion",
            ":release:1.0.0") {
            export = false
        }
    }
}

最后是ComedGrailsPlugin.groovy:的doWithSpring部分

def doWithSpring = {
    bayeux(BayeuxServerImpl) { bean ->
        bean.initMethod = 'start'
        bean.destroyMethod = 'stop'
    }
    // the CometdServlet will pick up the Bayeux object from the servlet context
    bayeuxAttributeExporter(ServletContextAttributeExporter) {
        attributes = [(BayeuxServer.ATTRIBUTE): ref('bayeux')]
    }        
}

希望这不是太多信息。在过去的几天里，我一直在努力解决这个问题，但已经没有什么想法了，真的需要一些帮助

Answer 1

这似乎与Grails 2.0.0中的一个错误有关。升级到Grails 2.0.1（今天发布）后，错误自行解决。