Constructor Detail

• AttributeValueExp

  @Deprecated
  public AttributeValueExp()

  Deprecated. An instance created with this constructor cannot be used in a query.
  An AttributeValueExp with a null attribute.

• AttributeValueExp

  public AttributeValueExp(String attr)

  Creates a new AttributeValueExp representing the specified object attribute, named attr.

  Parameters:

  attr - the name of the attribute whose value is the value of this ValueExp.

Method Detail

• getAttributeName

  public String getAttributeName()

  Returns a string representation of the name of the attribute.

  Returns:

  the attribute name.

• apply

  public ValueExp apply(ObjectName name)
                 throws BadStringOperationException,
                        BadBinaryOpValueExpException,
                        BadAttributeValueExpException,
                        InvalidApplicationException

  Applies the AttributeValueExp on an MBean. This method calls getAttribute(name) and wraps the result as a ValueExp. The value returned by getAttribute must be a Number, String, or Boolean; otherwise this method throws a BadAttributeValueExpException, which will cause the containing query to be false for this name.

  Specified by:

  apply in interface ValueExp

  Parameters:

  name - The name of the MBean on which the AttributeValueExp will be applied.

  Returns:

  The ValueExp.

  Throws:

  BadAttributeValueExpException

  InvalidApplicationException

  BadStringOperationException

  BadBinaryOpValueExpException

• toString

  public String toString()

  Returns the string representing its value.

  Overrides:

  toString in class Object

  Returns:

  a string representation of the object.

• setMBeanServer

  @Deprecated
  public void setMBeanServer(MBeanServer s)

  Deprecated. This method has no effect. The MBean Server used to obtain an attribute value is QueryEval.getMBeanServer().
  Sets the MBean server on which the query is to be performed.

  Specified by:

  setMBeanServer in interface ValueExp

  Parameters:

  s - The MBean server on which the query is to be performed.

• getAttribute

  protected Object getAttribute(ObjectName name)

  Return the value of the given attribute in the named MBean. If the attempt to access the attribute generates an exception, return null.

  The MBean Server used is the one returned by QueryEval.getMBeanServer().

  Parameters:

  name - the name of the MBean whose attribute is to be returned.

  Returns:

  the value of the attribute, or null if it could not be obtained.