public interface CompositeDataView
A Java class can implement this interface to indicate how it is
to be converted into a CompositeData
by the MXBean framework.
A typical way to use this class is to add extra items to the
CompositeData
in addition to the ones that are declared in the
CompositeType
supplied by the MXBean framework. To do this,
you must create another CompositeType
that has all the same items,
plus your extra items.
For example, suppose you have a class Measure
that consists of
a String called units
and a value
that is either a
long
or a double
. It might look like this:
public class Measure implements CompositeDataView { private String units; private Number value; // a Long or a Double public Measure(String units, Number value) { this.units = units; this.value = value; } public static Measure from(CompositeData cd) { return new Measure((String) cd.get("units"), (Number) cd.get("value")); } public String getUnits() { return units; } // Can't be called getValue(), because Number is not a valid type // in an MXBean, so the implied "value" property would be rejected. public Number _getValue() { return value; } public CompositeData toCompositeData(CompositeType ct) { try {List<String> itemNames = new ArrayList<String>(ct.keySet());
List<String> itemDescriptions = new ArrayList<String>();
List<OpenType<?>> itemTypes = new ArrayList<OpenType<?>>();
for (String item : itemNames) { itemDescriptions.add(ct.getDescription(item)); itemTypes.add(ct.getType(item)); } itemNames.add("value"); itemDescriptions.add("long or double value of the measure"); itemTypes.add((value instanceof Long) ? SimpleType.LONG : SimpleType.DOUBLE); CompositeType xct = new CompositeType(ct.getTypeName(), ct.getDescription(), itemNames.toArray(new String[0]), itemDescriptions.toArray(new String[0]), itemTypes.toArray(new OpenType<?>[0])); CompositeData cd = new CompositeDataSupport(xct, new String[] {"units", "value"}, new Object[] {units, value}); assert ct.isValue(cd); // check we've done it right return cd; } catch (Exception e) { throw new RuntimeException(e); } } }
The CompositeType
that will appear in the openType
field
of the Descriptor
for an attribute or
operation of this type will show only the units
item, but the actual
CompositeData
that is generated will have both units
and
value
.
- Since:
- 1.6
- See Also:
MXBean
-
Method Summary
Modifier and Type Method Description CompositeData
toCompositeData(CompositeType ct)
Return aCompositeData
corresponding to the values in this object.
-
Method Details
-
toCompositeData
Return a
CompositeData
corresponding to the values in this object. The returned value should usually be an instance ofCompositeDataSupport
, or a class that serializes as aCompositeDataSupport
via awriteReplace
method. Otherwise, a remote client that receives the object might not be able to reconstruct it.- Parameters:
ct
- The expectedCompositeType
of the returned value. If the returned value iscd
, thencd.getCompositeType().equals(ct)
should be true. Typically this will be becausecd
is aCompositeDataSupport
constructed withct
as itsCompositeType
.- Returns:
- the
CompositeData
.
-