Developing Applications with WebLogic SIP Server

Generating SNMP Traps from Application Code

The following sections describe how to use the WebLogic SIP Server SipServletSnmpTrapRuntimeMBean to generate SNMP traps from within a SIP Servlet:

See Configuring SNMP in the Operations Guide for information about configuring SNMP in a WebLogic SIP Server domain.

Overview

WebLogic SIP Server includes a runtime MBean, SipServletSnmpTrapRuntimeMBean, that enables applications to easily generate SNMP traps. The WebLogic SIP Server MIB contains seven new OIDs that are reserved for traps generated by an application. Each OID corresponds to a severity level that the application can assign to a trap, in order from the least severe to the most severe:

To generate a trap, an application simply obtains an instance of the SipServletSnmpTrapRuntimeMBean and then executes a method that corresponds to the desired trap severity level (sendInfoTrap(), sendWarningTrap(), sendErrorTrap(), sendNoticeTrap(), sendCriticalTrap(), sendAlertTrap(), and sendEmergencyTrap()). Each method takes a single parameter—the String value of the trap message to generate.

For each SNMP trap generated in this manner, WebLogic SIP Server also automatically transmits the Servlet name, application name, and WebLogic SIP Server instance name associated with the calling Servlet.

Requirement for Accessing SipServletSnmpTrapRuntimeMBean

In order to obtain a SipServletSnmpTrapRuntimeMBean, the calling SIP Servlet must be able to perform MBean lookups from the Servlet context. To enable this functionality, you must assign a WebLogic SIP Server administrator role-name entry to the security-role and run-as role elements in the sip.xml deployment descriptor. Listing 15-1 shows a sample sip.xml file with the required role elements highlighted.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE sip-app

   PUBLIC "-//Java Community Process//DTD SIP Application 1.0//EN"

   "http://www.jcp.org/dtd/sip-app_1_0.dtd">

<sip-app>

  <display-name>My SIP Servlet</display-name>

  <distributable/>

  <servlet>

    <servlet-name>myservlet</servlet-name>

    <servlet-class>com.mycompany.MyServlet</servlet-class>

    <run-as>

      <role-name>weblogic</role-name>

    </run-as>

  </servlet>

  <servlet-mapping>

    <servlet-name>myservlet</servlet-name>

    <pattern>

      <equal>

	<var>request.method</var>

	<value>INVITE</value>

      </equal>

    </pattern>

  </servlet-mapping>

  <security-role>

    <role-name>weblogic</role-name>

  </security-role>

</sip-app>

Obtaining a Reference to SipServletSnmpTrapRuntimeMBean

Any SIP Servlet that generates SNMP traps must first obtain a reference to the SipServletSnmpTrapRuntimeMBean. Listing 15-2 shows the sample code for a method to obtain the MBean.

public SipServletSnmpTrapRuntimeMBean getServletSnmpTrapRuntimeMBean() {

    MBeanHome localHomeB = null;

    SipServletSnmpTrapRuntimeMBean ssTrapMB = null;

    try

    {

      Context ctx = new InitialContext();

      localHomeB = (MBeanHome)ctx.lookup(MBeanHome.LOCAL_JNDI_NAME);

      ctx.close();

    } catch (NamingException ne){

      ne.printStackTrace();

    }

    Set set = localHomeB.getMBeansByType("SipServletSnmpTrapRuntime");

    if (set == null || set.isEmpty()) {

      try {

        throw new ServletException("Unable to lookup type 'SipServletSnmpTrapRuntime'");

      } catch (ServletException e) {

        e.printStackTrace();

      }

    }

    ssTrapMB = (SipServletSnmpTrapRuntimeMBean) set.iterator().next();

    return ssTrapMB;

}

Generating a SNMP Trap

In combination with the method shown in Listing 15-2, Listing 15-3 demonstrates how a SIP Servlet would use the MBean instance to generate an SNMP trap in response to a SIP INVITE.

public class MyServlet extends SipServlet {

  private SipServletSnmpTrapRuntimeMBean sipServletSnmpTrapMb = null;

  public MyServlet () {

  }

  public void init (ServletConfig sc) throws ServletException {

    super.init (sc);

    sipServletSnmpTrapMb = getServletSnmpTrapRuntimeMBean();

  }

  protected void doInvite(SipServletRequest req) throws IOException {

    sipServletSnmpTrapMb.sendInfoTrap("Rx Invite from " + req.getRemoteAddr() + "with call id" + req.getCallId());

  }

}