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No EJB receiver available for handling ...

程序员文章站 2022-07-13 09:57:50
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No EJB receiver available for handling ...

在Jboss EAP 6中,调用远程EJB时出现这个错误, 原因可能是JNDI格式写错了。EJB JNDI的格式如下:

 

ejb:<appName>/<moduleName>/<distinctName>/<beanName>!<viewClassName>?stateful

 

注意appName前是没有"/"的!如没有distinctName,留空,即连续两个”//“。

 

在jboss-eap-quickstarts-6.4.0.GA提供了样例代码ejb-remote:

 

public interface RemoteCalculator {

    int add(int a, int b);

    int subtract(int a, int b);
}

@Stateless
@Remote(RemoteCalculator.class)
public class CalculatorBean implements RemoteCalculator {

    @Override
    public int add(int a, int b) {
        return a + b;
    }

    @Override
    public int subtract(int a, int b) {
        return a - b;
    }
}

public class RemoteEJBClient {

    public static void main(String[] args) throws Exception {
        // Invoke a stateless bean
        invokeStatelessBean();

        // Invoke a stateful bean
        invokeStatefulBean();
    }

    private static void invokeStatelessBean() throws NamingException {
        // Let's lookup the remote stateless calculator
        final RemoteCalculator statelessRemoteCalculator = lookupRemoteStatelessCalculator();
        System.out.println("Obtained a remote stateless calculator for invocation");
        // invoke on the remote calculator
        int a = 204;
        int b = 340;
        System.out.println("Adding " + a + " and " + b + " via the remote stateless calculator deployed on the server");
        int sum = statelessRemoteCalculator.add(a, b);
        System.out.println("Remote calculator returned sum = " + sum);
        if (sum != a + b) {
            throw new RuntimeException("Remote stateless calculator returned an incorrect sum " + sum + " ,expected sum was "
                    + (a + b));
        }
        // try one more invocation, this time for subtraction
        int num1 = 3434;
        int num2 = 2332;
        System.out.println("Subtracting " + num2 + " from " + num1
                + " via the remote stateless calculator deployed on the server");
        int difference = statelessRemoteCalculator.subtract(num1, num2);
        System.out.println("Remote calculator returned difference = " + difference);
        if (difference != num1 - num2) {
            throw new RuntimeException("Remote stateless calculator returned an incorrect difference " + difference
                    + " ,expected difference was " + (num1 - num2));
        }
    }

...

    private static RemoteCalculator lookupRemoteStatelessCalculator() throws NamingException {
        final Hashtable<String, String> jndiProperties = new Hashtable<String, String>();
        jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
        final Context context = new InitialContext(jndiProperties);

        return (RemoteCalculator) context.lookup("ejb:/jboss-ejb-remote-server-side/CalculatorBean!" + RemoteCalculator.class.getName());
    }

...
}

 

 jboss-ejb-client.properties(放在resources根目录下)

remote.connectionprovider.create.options.org.xnio.Options.SSL_ENABLED=false

remote.connections=default

remote.connection.default.host=localhost
remote.connection.default.port = 4447
remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOANONYMOUS=false

 

Client pom.xml

    <dependencyManagement>
      <dependencies>
         <dependency>
            <groupId>org.jboss.spec</groupId>
            <artifactId>jboss-javaee-6.0</artifactId>
            <version>${version.jboss.spec.javaee.6.0}</version>
            <type>pom</type>
            <scope>import</scope>
         </dependency>

         <dependency>
             <groupId>org.jboss.as</groupId>
             <artifactId>jboss-as-ejb-client-bom</artifactId>
             <version>${version.jboss.as}</version>
             <type>pom</type>
             <scope>import</scope>
         </dependency>
      </dependencies>
   </dependencyManagement>

   <dependencies>
       <!-- Import the transaction spec API, we use runtime scope because we aren't using any direct
        reference to the spec API in our client code -->
      <dependency>
         <groupId>org.jboss.spec.javax.transaction</groupId>
         <artifactId>jboss-transaction-api_1.1_spec</artifactId>
         <scope>runtime</scope>
      </dependency>

      <!-- Import the EJB 3.1 API, we use runtime scope because we aren't using any direct
       reference to EJB spec API in our client code -->
      <dependency>
         <groupId>org.jboss.spec.javax.ejb</groupId>
         <artifactId>jboss-ejb-api_3.1_spec</artifactId>
         <scope>runtime</scope>
      </dependency>

       <!-- We depend on the EJB remote business interfaces  of this application -->
       <dependency>
          <groupId>org.jboss.quickstarts.eap</groupId>
          <artifactId>jboss-ejb-remote-server-side</artifactId>
          <type>ejb-client</type>
         <version>${project.version}</version>
       </dependency>

       <!-- JBoss EJB client API jar. We use runtime scope because the EJB client API
        isn't directly used in this example. We just need it in our runtime classpath -->
       <dependency>
           <groupId>org.jboss</groupId>
           <artifactId>jboss-ejb-client</artifactId>
           <scope>runtime</scope>
       </dependency>

       <!-- client communications with the server use XNIO -->
       <dependency>
           <groupId>org.jboss.xnio</groupId>
           <artifactId>xnio-api</artifactId>
           <scope>runtime</scope>
       </dependency>

       <dependency>
           <groupId>org.jboss.xnio</groupId>
           <artifactId>xnio-nio</artifactId>
           <scope>runtime</scope>
       </dependency>

      <!-- The client needs JBoss remoting to access the server -->
       <dependency>
            <groupId>org.jboss.remoting3</groupId>
            <artifactId>jboss-remoting</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- Remote EJB accesses can be secured -->
        <dependency>
            <groupId>org.jboss.sasl</groupId>
            <artifactId>jboss-sasl</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- data serialization for invoking remote EJBs -->
        <dependency>
            <groupId>org.jboss.marshalling</groupId>
            <artifactId>jboss-marshalling-river</artifactId>
            <scope>runtime</scope>
        </dependency>

    </dependencies>

 

 

例子是以jar包的形式部署到jboss中的,查看jboss日志,能查找到:

java:jboss/exported/jboss-ejb-remote-server-side/CalculatorBean!org.jboss.as.quickstarts.ejb.remote.stateless.RemoteCalculator

 

以jar包的形式部署,访问时写法:

context.lookup("ejb:/jboss-ejb-remote-server-side/CalculatorBean!" + RemoteCalculator.class.getName());

我将其移到ear中,改为如下写法:

context.lookup("ejb:/myear/myejb/CalculatorBean!" + RemoteCalculator.class.getName());

就出现了No EJB receiver available for handling ...,注意要去掉"/"!

 

注意:By default WildFly uses 8080 as the remoting port. The EJB client API uses the http port, with the http-upgrade functionality, for communicating with the server for remote invocations(unless the server is configured for some other http port)

 

更详细信息请参见

EJB JNDI Naming Reference

Invoke a Session Bean Remotely using JNDI(EAP 6)

EJB invocations from a remote client using JNDI(Wildfly 8)

Remote EJB invocations via JNDI - EJB client API or remote-naming project

Download the Quickstart Code Examples