This annotation defines an attribute in either CompositeData (ManagedData) or
an open MBean (ManagedObject). An attribute may be read/write (has a setter
and a getter), read only (only has a getter),
or write only (only has a setter) depending on the declared methods in the class.
A method defines a getter if it returns a non-void type and takes no argument types.
Likewise a method defines a setter if it return void and takes exactly one
argument.
An id is derived from a method name as follows:
- If the method is a getter, and has a name of the form getXXX, the derived
id is xXX (note the initial lower case change).
- If the method is a getter with a boolean return type, and has a name of
the form isXXX, the derived id is xXX
- If the method is a setter, and has a name of the form setXXX, the
detived id is xXX.
- Otherwise the derived ID is the method name.
In certain cases, a field annotated with @ManagedAttribute
may also represent a read-only attribute.
The field must be final, and its type must be one of:
- A primitive type (boolean, byte, short, char, int, long, float, double)
- A primitive type wrapper (Boolean, Byte, Short, Character, Integer,
Long, Float, Double)
- A String
- A BigDecimal or BigInteger
- A java.util.Date
- An ObjectName
- An enum (which is translated to its ordinal name)
Any such field can be accessed safely by multiple threads, because its value
cannot change after an instance of the containing class has completed its
constructor. Note that Date is not truly immutable (it should be!), but it's
one of the Open MBean simple types, so it is included here.