| 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
- An object name pattern, within the context of a query
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:
- Another backslash. The second backslash has no special
meaning and the two characters represent a single blackslash.
- The character 'n'. The two characters represent a newline
('\n' in Java).
- A quote. The two characters represent a quote, and that quote
is not considered to terminate the quoted value. An ending closing
quote must be present for the quoted value to be valid.
- A question mark (?) or star (*). The two characters represent
a question mark or star respectively.
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:
- The domain.
- A colon (
:).
- A key property list as defined below.
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.
author:
Young Yang | 