/*
 * @(#)QualifiedAttributeValueExp.java	4.18 03/12/19
 * 
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.management;


/**
 * This class represents indexed attributes used as arguments to relational
 * constraints. An QualifiedAttributeValueExp may be used anywhere a
 * ValueExp is required.
 * @serial include
 *
 * @since 1.5
 */
class QualifiedAttributeValueExp extends AttributeValueExp   { 


    /* Serial version */
    private static final long serialVersionUID = 8832517277410933254L;

    /**
     * @serial The attribute class name
     */
    private String className;
        

    /**
     * Basic Constructor.
     */
    public QualifiedAttributeValueExp() { 
    } 

    /**
     * Creates a new QualifiedAttributeValueExp representing the specified object
     * attribute, named attr with class name className.
     */
    public QualifiedAttributeValueExp(String className, String attr) { 
	super(attr);
	this.className = className;
    } 


    /**
     * Returns a string representation of the class name of the attribute.
     */
    public String getAttrClassName()  { 
	return className;
    } 

    /**
     * Applies the QualifiedAttributeValueExp to an MBean.
     *
     * @param name The name of the MBean on which the QualifiedAttributeValueExp will be applied.
     *
     * @return  The ValueExp.
     *
     * @exception BadStringOperationException
     * @exception BadBinaryOpValueExpException
     * @exception BadAttributeValueExpException 
     * @exception InvalidApplicationException
     */
    public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException,
	BadAttributeValueExpException, InvalidApplicationException  {
	try {
	    MBeanServer server = QueryEval.getMBeanServer();
	    String v = server.getObjectInstance(name).getClassName();
	    
	    if (v.equals(className)) {
		return super.apply(name);
	    }
	    throw new InvalidApplicationException("Class name is " + v +
						  ", should be " + className);
	    
	} catch (Exception e) {
	    throw new InvalidApplicationException("Qualified attribute: " + e);
	    /* Can happen if MBean disappears between the time we
	       construct the list of MBeans to query and the time we
	       evaluate the query on this MBean, or if
	       getObjectInstance throws SecurityException.  */
	}
    } 
    
    /**
     * Returns the string representing its value
     */        
    public String toString()  { 
	if (className != null) {
	    return className + "." + super.toString();
	} else {
	    return super.toString();
	}
    } 
    
}