Working with an MBean server - JMX in Action - page 182

Table 8.9 Methods of the Query class that create QueryExp objects (or subclasses) that can be
used in more complex query expressions. (continued)

Method Return type Description

Creates an expression that means the first ValueExp
should be less than the second

lt( ValueExp,
ValueExp)

QueryExp

Creates an expression that means the first ValueExp
should match the String expression represented by
the second argument; for example, the second argu-
ment might be va*lu?

match( AttributeValue-
Exp, StringValueExp)

QueryExp

Creates an expression that means the first ValueExp
should have a prefix matching the String expression
represented by the second argument; for example, the
second argument might be va*lu?

initialSubString(
AttributeValueExp,
StringValueExp)

QueryExp

Creates an expression that means the first ValueExp
should contain the String expression represented by
the second argument; for example, the second argu-
ment might be va*lu?

anySubString(
AttributeValueExp,
StringValueExp)

QueryExp

Creates an expression that means the first ValueExp
should have a suffix matching the String expression
represented by the second argument; for example, the
second argument might be va*lu?

finalSubString(
AttributeValueExp,
StringValueExp)

QueryExp

If you are overwhelmed with all these methods right now, don't worry—the next
section presents several examples to get you started.

8.3.3 Constructing examples

Now that you have seen the methods of the Query class that are used to create
simple and complex queries, we can present some examples. To create meaning-
ful query examples, let's first imagine the scenario in which the example queries
might exist. Each query will be described in a textual sentence, and then shown
in code using the methods of the Query class.
Imagine you have a JMX agent with the domain Hardware . The agent will con-
tain five MBeans that monitor different pieces of hardware (modem, printer, and
so forth). Each MBean has its own unique object name, but some MBeans have
common attributes. Table 8.10 lists the devices being monitored, along with the
object names and a few attributes of the MBeans.
Use this table as a reference as you develop the queries in the following para-
graphs. As you can see, you have five devices ranging from modems to a fax
machine. All the devices have a status attribute, and one has an error value.
The printer, fax, and copier all have identical attributes with varying values (as