The Instance Provider Interface (InstanceProvider)

The following table describes the methods in the instance provider interface in the Provider package (com.sun.wbem.provider20).

These methods each take the op argument, the CIMObjectPath of the specified CIM class or CIM instance. The object path includes the namespace, class name, and keys (if the object is an instance). The namespace is a directory that can contain other namespaces, classes, instances, and qualifier types. A key is a property that uniquely identifies an instance of a class. Key properties have a KEY qualifier.

For example, the following object path has two parts:

\\myserver\root\cimv2\Solaris_ComputerSystem:Name=mycomputer:   CreationClassName=Solaris_ComputerSystem

• \\myserver\root\cimv2

  The default CIM namespace on host myserver.

• Solaris_ComputerSystem:Name=mycomputer: CreationClassName=Solaris_ComputerSystem

  A specific Solaris Computer System object in the default namespace on host myserver. This Solaris computer system is uniquely identified by two key property values in the format (property=value):

  • Name=mycomputer

  • CreationClassName=Solaris_ComputerSystem

Example — Implementing an Instance Provider

The following example shows the Java source code for an instance provider, SimpleInstanceProvider, that implements the enumInstances and getInstance interfaces for the Ex_SimpleInstanceProvider class. For brevity, this example implements the deleteInstance, createInstance, setInstance, and execQuery interfaces by throwing a CIMException. In practice, an instance provider must implement all InstanceProvider interfaces.

Example 5–1 SimpleInstanceProvider Instance Provider

/*
 * "@(#)SimpleInstanceProvider.java"
 */
import com.sun.wbem.cim.*;
import com.sun.wbem.client.*;
import com.sun.wbem.provider.CIMProvider;
import com.sun.wbem.provider20.InstanceProvider;
import com.sun.wbem.provider.MethodProvider;
import java.util.*;
import java.io.*;

public class SimpleInstanceProvider implements InstanceProvider{
     static int loop = 0;
     public void initialize(CIMOMHandle cimom) throws CIMException {
     }
     public void cleanup() throws CIMException {
     }
     public Vector enumInstances(CIMObjectPath op, boolean deep, CIMClass cc,
            boolean localOnly) throws CIMException {
                return null;
     }
     /*
      * enumInstances:
      * The entire instances and not just the names are returned.
      * Deep or shallow enumeration is possible, however
      * currently the CIMOM only asks for shallow enumeration.
      */
     public Vector enumInstances(CIMObjectPath op, boolean deep, CIMClass cc)
             throws CIMException {
         if (op.getObjectName().equalsIgnoreCase("Ex_SimpleInstanceProvider")) 
             {
             Vector instances = new Vector();
             CIMObjectPath cop = new CIMObjectPath(op.getObjectName(),
                     op.getNameSpace());
                 if (loop == 0){
                     cop.addKey("First", new CIMValue("red"));
                     cop.addKey("Last", new CIMValue("apple"));
                     // To delete this class, comment this following 
	                    // line and compile it.
                     instances.addElement(cop);
                     loop += 1;
                 } else {
                     cop.addKey("First", new CIMValue("red"));
                     cop.addKey("Last", new CIMValue("apple"));
                     // To delete this class, comment this following 
                     // line and compile it.
                     instances.addElement(cop);
                     cop = new CIMObjectPath(op.getObjectName(),
                             op.getNameSpace());
                     cop.addKey("First", new CIMValue("green"));
                     cop.addKey("Last", new CIMValue("apple"));
                     // To delete this class, comment this following 
                     // line and compile it.
                     instances.addElement(cop);
                 }
             return instances;
             }
         return new Vector();
     }

     public CIMInstance getInstance(CIMObjectPath op, 
             CIMClass cc, boolean localOnly) throws CIMException {
             if (op.getObjectName().equalsIgnoreCase("Ex_SimpleInstanceProvider"))
             {
                 CIMInstance ci = cc.newInstance();
                 ci.setProperty("First", new CIMValue("yellow"));
                 ci.setProperty("Last", new CIMValue("apple"));
                 return ci;
             }
            return new CIMInstance();
      }

     public Vector execQuery(CIMObjectPath op, String query, int ql, CIMClass cc)
             throws CIMException {
                 throw(new CIMException(CIMException.CIM_ERR_NOT_SUPPORTED));
    }

     public void setInstance(CIMObjectPath op, CIMInstance ci)
             throws CIMException {
                 throw(new CIMException(CIMException.CIM_ERR_NOT_SUPPORTED));
    }

     public CIMObjectPath createInstance(CIMObjectPath op, CIMInstance ci)
              throws CIMException {
                 throw(new CIMException(CIMException.CIM_ERR_NOT_SUPPORTED));
    }

     public void deleteInstance(CIMObjectPath cp) throws CIMException {
         throw(new CIMException(CIMException.CIM_ERR_NOT_SUPPORTED));
     }
 }