javax.management: public class: AttributeValueExp

javax.management
public class: AttributeValueExp [javadoc | source]

java.lang.Object
   javax.management.AttributeValueExp

All Implemented Interfaces:
ValueExp

Direct Known Subclasses:
QualifiedAttributeValueExp, ClassAttributeValueExp

Represents attributes used as arguments to relational constraints. Instances of this class are usually obtained using Query.attr .

An AttributeValueExp may be used anywhere a ValueExp is required.

since: 1.5 -

Constructor:

Constructor:
public AttributeValueExp() { } An `AttributeValueExp` with a null attribute.
public AttributeValueExp(String attr) { this.attr = attr; } Creates a new `AttributeValueExp` representing the specified object attribute, named attr. Parameters: `attr` - the name of the attribute whose value is the value of this ValueExp .

 public AttributeValueExp() {

}

An AttributeValueExp with a null attribute.

 public AttributeValueExp(String attr) {
        this.attr = attr;
}

AttributeValueExp

Parameters:

attr - the name of the attribute whose value is the value of this ValueExp .

Method from javax.management.AttributeValueExp Summary:
apply, getAttribute, getAttributeName, setMBeanServer, toString

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from javax.management.AttributeValueExp Detail:
public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException, BadAttributeValueExpException, InvalidApplicationException { Object result = getAttribute(name); if (result instanceof Number) { return new NumericValueExp((Number)result); } else if (result instanceof String) { return new StringValueExp((String)result); } else if (result instanceof Boolean) { return new BooleanValueExp((Boolean)result); } else { throw new BadAttributeValueExpException(result); } } Applies the `AttributeValueExp` on an MBean. This method calls getAttribute(name) and wraps the result as a {@code ValueExp}. The value returned by {@code getAttribute} must be a {@code Number}, {@code String}, or {@code Boolean}; otherwise this method throws a {@code BadAttributeValueExpException}, which will cause the containing query to be false for this {@code name}.
protected Object getAttribute(ObjectName name) { try { // Get the value from the MBeanServer MBeanServer server = QueryEval.getMBeanServer(); return server.getAttribute(name, attr); } catch (Exception re) { return null; } } Return the value of the given attribute in the named MBean. If the attempt to access the attribute generates an exception, return null. The MBean Server used is the one returned by QueryEval#getMBeanServer() .
public String getAttributeName() { return attr; } Returns a string representation of the name of the attribute.
public void setMBeanServer(MBeanServer s) { } Deprecated! `This` - method has no effect. The MBean Server used to obtain an attribute value is QueryEval#getMBeanServer() . Sets the MBean server on which the query is to be performed.
public String toString() { return attr; } Returns the string representing its value.

Method from javax.management.AttributeValueExp Detail:

 public ValueExp apply(ObjectName name) throws BadStringOperationException, BadBinaryOpValueExpException, BadAttributeValueExpException, InvalidApplicationException {
        Object result = getAttribute(name);
        if (result instanceof Number) {
            return new NumericValueExp((Number)result);
        } else if (result instanceof String) {
            return new StringValueExp((String)result);
        } else if (result instanceof Boolean) {
            return new BooleanValueExp((Boolean)result);
        } else {
            throw new BadAttributeValueExpException(result);
        }
}

Applies the AttributeValueExp on an MBean. This method calls getAttribute(name) and wraps the result as a {@code ValueExp}. The value returned by {@code getAttribute} must be a {@code Number}, {@code String}, or {@code Boolean}; otherwise this method throws a {@code BadAttributeValueExpException}, which will cause the containing query to be false for this {@code name}.

 protected Object getAttribute(ObjectName name) {
        try {
            // Get the value from the MBeanServer
            MBeanServer server = QueryEval.getMBeanServer();
            return server.getAttribute(name, attr);
        } catch (Exception re) {
            return null;
        }
}

Return the value of the given attribute in the named MBean. If the attempt to access the attribute generates an exception, return null.

The MBean Server used is the one returned by QueryEval#getMBeanServer() .

 public String getAttributeName() {
        return attr;
}

Returns a string representation of the name of the attribute.

 public  void setMBeanServer(MBeanServer s) {

}

Deprecated! This - method has no effect. The MBean Server used to obtain an attribute value is QueryEval#getMBeanServer() .

Sets the MBean server on which the query is to be performed.

 public String toString() {
        return attr;
}

Returns the string representing its value.