AttributeValueExp (Java SE 15 & JDK 15) (original) (raw)

All Implemented Interfaces:

[Serializable](../../../java.base/java/io/Serializable.html "interface in java.io"), [ValueExp](ValueExp.html "interface in javax.management")

public class AttributeValueExp extends Object implements ValueExp

Represents attributes used as arguments to relational constraints. Instances of this class are usually obtained using Query.attr.

An AttributeValueExp may be used anywhere aValueExp is required.

Since:

1.5

See Also:

Serialized Form

• Constructor Summary

Constructors

• Method Summary

• Constructor Details

  • AttributeValueExp

  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 Details

  • getAttributeName

  public String getAttributeName()
  Returns a string representation of the name of the attribute.
  Returns:
  the attribute name.

  • apply

  Applies the AttributeValueExp on an MBean. This method calls getAttribute(name) and wraps the result as a ValueExp. The value returned bygetAttribute must be a Number, String, or Boolean; otherwise this method throws aBadAttributeValueExpException, which will cause the containing query to be false for this name.
  Specified by:
  [apply](ValueExp.html#apply%28javax.management.ObjectName%29) in interface [ValueExp](ValueExp.html "interface in javax.management")
  Parameters:
  name - The name of the MBean on which the AttributeValueExp will be applied.
  Returns:
  The ValueExp.
  Throws:
  [BadStringOperationException](BadStringOperationException.html "class in javax.management") - when an invalid string operation is passed to a method for constructing a query
  [BadBinaryOpValueExpException](BadBinaryOpValueExpException.html "class in javax.management") - when an invalid expression is passed to a method for constructing a query
  [BadAttributeValueExpException](BadAttributeValueExpException.html "class in javax.management") - when an invalid MBean attribute is passed to a query constructing method
  [InvalidApplicationException](InvalidApplicationException.html "class in javax.management") - when an invalid apply is attempted

  • toString

  Returns the string representing its value.
  Overrides:
  [toString](../../../java.base/java/lang/Object.html#toString%28%29) in class [Object](../../../java.base/java/lang/Object.html "class in java.lang")
  Returns:
  a string representation of the object.

  • setMBeanServer

  Sets the MBean server on which the query is to be performed.
  Specified by:
  [setMBeanServer](ValueExp.html#setMBeanServer%28javax.management.MBeanServer%29) in interface [ValueExp](ValueExp.html "interface in javax.management")
  Parameters:
  s - The MBean server on which the query is to be performed.

  • getAttribute

  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.