javax.management
Class ObjectName

java.lang.Object
  |
  +--javax.management.ObjectName

public class ObjectName
extends java.lang.Object
implements QueryExp, java.io.Serializable

Represents the object name of an MBean, or a pattern that can match the names of several MBeans. Instances of this class are immutable.

An instance of this class can be used to represent:

An object name consists of two parts, the domain and the key properties.

The domain is a string of characters not including the character colon (:).

If the domain includes at least one occurrence of the wildcard characters asterisk (*) or question mark (?), then the object name is a pattern. The asterisk matches any sequence of zero or more characters, while the question mark matches any single character.

If the domain is empty, it will be replaced in certain contexts by the default domain of the MBean server in which the ObjectName is used.

The key properties are an unordered set of keys and associated values.

Each key is a nonempty string of characters which may not contain any of the characters comma (,), equals (=), colon, asterisk, or question mark. The same key may not occur twice in a given ObjectName.

Each value associated with a key is a string of characters that is either unquoted or quoted.

An unquoted value is a possibly empty string of characters which may not contain any of the characters comma, equals, colon, quote, asterisk, or question mark.

A quoted value consists of a quote ("), followed by a possibly empty string of characters, followed by another quote. Within the string of characters, the backslash (\) has a special meaning. It must be followed by one of the following characters:

A quote, question mark, or star may not appear inside a quoted value except immediately after an odd number of consecutive backslashes.

The quotes surrounding a quoted value, and any backslashes within that value, are considered to be part of the value.

An ObjectName may be a property pattern. In this case it may have zero or more keys and associated values. It matches a nonpattern ObjectName whose domain matches and that contains the same keys and associated values, as well as possibly other keys and values.

An ObjectName is a pattern if its domain contains a wildcard or if the ObjectName is a property pattern.

If an ObjectName is not a pattern, it must contain at least one key with its associated value.

An ObjectName can be written as a String with the following elements in order:

A key property list written as a String is a comma-separated list of elements. Each element is either an asterisk or a key property. A key property consists of a key, an equals (=), and the associated value.

At most one element of a key property list may be an asterisk. If the key property list contains an asterisk element, the ObjectName is a property pattern.

Spaces have no special significance in a String representing an ObjectName. For example, the String:

 domain: key1 = value1 , key2 = value2
 
represents an ObjectName with two keys. The name of each key contains six characters, of which the first and last are spaces. The value associated with the key " key1 " also begins and ends with a space.

In addition to the restrictions on characters spelt out above, no part of an ObjectName may contain a newline character ('\n'), whether the domain, a key, or a value, whether quoted or unquoted. The newline character can be represented in a quoted value with the sequence \n.

The rules on special characters and quoting apply regardless of which constructor is used to make an ObjectName.

To avoid collisions between MBeans supplied by different vendors, a useful convention is to begin the domain name with the reverse DNS name of the organization that specifies the MBeans, followed by a period and a string whose interpretation is determined by that organization. For example, MBeans specified by Sun Microsystems Inc., DNS name sun.com, would have domains such as com.sun.MyDomain. This is essentially the same convention as for Java-language package names.

See Also:
Serialized Form

Constructor Summary
ObjectName(java.lang.String name)
          Allows an object name to be created from the given string.
ObjectName(java.lang.String domain, java.util.Hashtable table)
          Allows an object name with several key properties to be created.
ObjectName(java.lang.String domain, java.lang.String key, java.lang.String value)
          Allows an object name to be created using only one key property.
 
Method Summary
(package private) static void ()
           
 boolean apply(ObjectName name)
          Test whether this ObjectName, which may be a pattern, matches another ObjectName.
 boolean equals(java.lang.Object object)
          Compares the current object name with another object name.
 java.lang.String getCanonicalKeyPropertyListString()
          Returns a string representation of the list of key properties in which the key properties are sorted in lexical order.
 java.lang.String getCanonicalName()
          Returns the canonical form of the name; that is, a string representation where the properties are sorted in lexical order.
 java.lang.String getDomain()
          Returns the domain part.
static ObjectName getInstance(ObjectName name)
          Return an instance of ObjectName that can be used anywhere the given object can be used.
static ObjectName getInstance(java.lang.String name)
          Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(name) can be used.
static ObjectName getInstance(java.lang.String domain, java.util.Hashtable table)
          Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(domain, table) can be used.
static ObjectName getInstance(java.lang.String domain, java.lang.String key, java.lang.String value)
          Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(domain, key, value) can be used.
 java.lang.String getKeyProperty(java.lang.String property)
          Obtains the value of a key property in a key property.
 java.util.Hashtable getKeyPropertyList()
          Returns a pointer to the list of key properties.
 java.lang.String getKeyPropertyListString()
          Returns a string representation of the list of key properties specified at creation time.
 int hashCode()
          Returns a hash code for this object name.
 boolean isDomainPattern()
          Checks whether the object name is a pattern on the domain part.
 boolean isPattern()
          Checks if a name to be used is a pattern for a query.
 boolean isPropertyPattern()
          Checks whether the object name is a pattern on the key properties.
static java.lang.String quote(java.lang.String s)
          Returns a quoted form of the given String, suitable for inclusion in an ObjectName.
 void setMBeanServer(MBeanServer mbs)
          Sets the MBean server on which the query is to be performed.
 java.lang.String toString()
          Returns a string representation of the object name.
static java.lang.String unquote(java.lang.String q)
          Returns an unquoted form of the given String.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ObjectName

public ObjectName(java.lang.String name)
           throws MalformedObjectNameException,
                  java.lang.NullPointerException
Allows an object name to be created from the given string. If the string does not have the right format an MalformedObjectNameException should be raised.
Parameters:
name - - A string representation of the object name.
Throws:
MalformedObjectNameException - - the string passed in parameter does not have the right format.

ObjectName

public ObjectName(java.lang.String domain,
                  java.util.Hashtable table)
           throws MalformedObjectNameException,
                  java.lang.NullPointerException
Allows an object name with several key properties to be created. If the parameters do not have the right format an MalformedObjectNameException should be raised.
Parameters:
domain - - The domain part of the object name.
table - - A hash table containing one or more search keys. Each search key is an attribute-value pair.
Throws:
MalformedObjectNameException - - the string passed in parameter does not have the right format.

ObjectName

public ObjectName(java.lang.String domain,
                  java.lang.String key,
                  java.lang.String value)
           throws MalformedObjectNameException,
                  java.lang.NullPointerException
Allows an object name to be created using only one key property. If the parameters do not have the right format an MalformedObjectNameException should be raised.
Parameters:
domain - - The domain part of the object name.
key - - The attribute in the key property of the object name.
value - - The value in the key property of the object name.
Throws:
MalformedObjectNameException - - the string passed in parameter does not have the right format.
Method Detail

static void ()

getDomain

public java.lang.String getDomain()
Returns the domain part.
Returns:
This returns the domain name

getKeyProperty

public java.lang.String getKeyProperty(java.lang.String property)
                                throws java.lang.NullPointerException
Obtains the value of a key property in a key property.
Parameters:
property - - The property whose value is to be obtained.
Returns:
The value of the property.

getKeyPropertyList

public java.util.Hashtable getKeyPropertyList()
Returns a pointer to the list of key properties.
Returns:
This returns a HashTable of key properties

apply

public boolean apply(ObjectName name)
              throws java.lang.NullPointerException

Test whether this ObjectName, which may be a pattern, matches another ObjectName. If name is a pattern, the result is false. If this ObjectName is a pattern, the result is true if and only if name matches the pattern. If neither this ObjectName nor name is a pattern, the result is true if and only if the two ObjectNames are equal as described for the equals(Object) method.

Specified by:
apply in interface QueryExp
Parameters:
name - The name of the MBean to compare to.
Returns:
True if name matches this ObjectName.
Throws:
java.lang.NullPointerException - if name is null.

getInstance

public static ObjectName getInstance(java.lang.String name)
                              throws MalformedObjectNameException,
                                     java.lang.NullPointerException

Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(name) can be used. The returned object may be of a subclass of ObjectName. Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

Parameters:
name - A string representation of the object name.
Returns:
an ObjectName corresponding to the given String.
Throws:
MalformedObjectNameException - The string passed as a parameter does not have the right format.
java.lang.NullPointerException - The name parameter is null.

getInstance

public static ObjectName getInstance(java.lang.String domain,
                                     java.lang.String key,
                                     java.lang.String value)
                              throws MalformedObjectNameException,
                                     java.lang.NullPointerException

Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(domain, key, value) can be used. The returned object may be of a subclass of ObjectName. Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

Parameters:
domain - The domain part of the object name.
key - The attribute in the key property of the object name.
value - The value in the key property of the object name.
Returns:
an ObjectName corresponding to the given domain, key, and value.
Throws:
MalformedObjectNameException - The domain, key, or value contains an illegal character, or value does not follow the rules for quoting.
java.lang.NullPointerException - One of the parameters is null.

getInstance

public static ObjectName getInstance(java.lang.String domain,
                                     java.util.Hashtable table)
                              throws MalformedObjectNameException,
                                     java.lang.NullPointerException

Return an instance of ObjectName that can be used anywhere an object obtained with new ObjectName(domain, table) can be used. The returned object may be of a subclass of ObjectName. Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

Parameters:
domain - The domain part of the object name.
table - A hash table containing one or more key properties. The key of each entry in the table is the key of a key property in the object name. The associated value in the table is the associated value in the object name.
Returns:
an ObjectName corresponding to the given domain and key mappings.
Throws:
MalformedObjectNameException - The domain contains an illegal character, or one of the keys or values in table contains an illegal character, or one of the values in table does not follow the rules for quoting.
java.lang.NullPointerException - One of the parameters is null.

getInstance

public static ObjectName getInstance(ObjectName name)
                              throws java.lang.NullPointerException

Return an instance of ObjectName that can be used anywhere the given object can be used. The returned object may be of a subclass of ObjectName. If name is of a subclass of ObjectName, it is not guaranteed that the returned object will be of the same class.

The returned value may or may not be identical to name. Calling this method twice with the same parameters may return the same object or two equal but not identical objects.

Since ObjectName is immutable, it is not usually useful to make a copy of an ObjectName. The principal use of this method is to guard against a malicious caller who might pass an instance of a subclass with surprising behaviour to sensitive code. Such code can call this method to obtain an ObjectName that is known not to have surprising behaviour.

Parameters:
name - an instance of the ObjectName class or of a subclass
Returns:
an instance of ObjectName or a subclass that is known to have the same semantics. If name respects the semantics of ObjectName, then the returned object is equal (though not necessarily identical) to name.
Throws:
java.lang.NullPointerException - The name is null.

isDomainPattern

public boolean isDomainPattern()
Checks whether the object name is a pattern on the domain part.
Returns:
True if the name is a domain pattern, otherwise false.

isPattern

public boolean isPattern()
Checks if a name to be used is a pattern for a query.
Returns:
True if the name is a pattern, otherwise false.

quote

public static java.lang.String quote(java.lang.String s)
                              throws java.lang.NullPointerException

Returns a quoted form of the given String, suitable for inclusion in an ObjectName. The returned value can be used as the value associated with a key in an ObjectName. The String s may contain any character. Appropriate quoting ensures that the returned value is legal in an ObjectName.

The returned value consists of a quote ('"'), a sequence of characters corresponding to the characters of s, and another quote. Characters in s appear unchanged within the returned value except:

Parameters:
s - the String to be quoted.
Returns:
the quoted String.
Throws:
java.lang.NullPointerException - if s is null.

unquote

public static java.lang.String unquote(java.lang.String q)
                                throws java.lang.IllegalArgumentException,
                                       java.lang.NullPointerException

Returns an unquoted form of the given String. If q is a String returned by quote(s), then unquote(q).equals(s). If there is no String s for which quote(s).equals(q), then unquote(q) throws an IllegalArgumentException.

These rules imply that there is a one-to-one mapping between quoted and unquoted forms.

Parameters:
q - the String to be unquoted.
Returns:
the unquoted String.
Throws:
java.lang.IllegalArgumentException - if q could not have been returned by the quote(java.lang.String) method, for instance if it does not begin and end with a quote (").
java.lang.NullPointerException - if q is null.

setMBeanServer

public void setMBeanServer(MBeanServer mbs)
Description copied from interface: QueryExp
Sets the MBean server on which the query is to be performed.
Specified by:
setMBeanServer in interface QueryExp
Tags copied from interface: QueryExp
Parameters:
server - The MBean server on which the query is to be performed.

toString

public java.lang.String toString()
Returns a string representation of the object name.
Overrides:
toString in class java.lang.Object
Returns:
This returns the string representation of the oject name

equals

public boolean equals(java.lang.Object object)
Compares the current object name with another object name. Two ObjectName instances are equal if and only if their canonical forms are equal. The canonical form is the string described for getCanonicalName().
Overrides:
equals in class java.lang.Object
Parameters:
object - The object name that the current object name is to be compared with.
Returns:
True if object is an ObjectName whose canonical form is equal to that of this ObjectName.

hashCode

public int hashCode()
Returns a hash code for this object name.
Overrides:
hashCode in class java.lang.Object
Returns:
This returns a hash code of type int for this object name

getCanonicalName

public java.lang.String getCanonicalName()
Returns the canonical form of the name; that is, a string representation where the properties are sorted in lexical order.
Returns:
Returns the canonical form of the name; that is, a string representation where the properties are sorted in lexical order.

getKeyPropertyListString

public java.lang.String getKeyPropertyListString()
Returns a string representation of the list of key properties specified at creation time.
Returns:
This returns a string representation of the list of key properties

getCanonicalKeyPropertyListString

public java.lang.String getCanonicalKeyPropertyListString()
Returns a string representation of the list of key properties in which the key properties are sorted in lexical order. This is used in lexicographic comparisons performed in order to select MBeans based on their key property list.
Returns:
This returns a string representation of the list of key properties in which the key properties are sorted in lexical order.

isPropertyPattern

public boolean isPropertyPattern()
Checks whether the object name is a pattern on the key properties.
Returns:
true if the name is a pattern, otherwise false