javax.slee.facilities.TimerPreserveMissed Maven / Gradle / Ivy
package javax.slee.facilities;
import java.io.Serializable;
import java.io.StreamCorruptedException;
/**
* This class defines an enumerated type for the late-timer preservation options
* suppored by the {@link TimerFacility Timer Facility}. A singleton instance of
* each enumerated value is guaranteed (via an implementation of readResolve()
* - refer {@link java.io.Serializable java.io.Serializable}), so that equality tests
* using == are always evaluated correctly. (This equality test is only
* guaranteed if this class is loaded in the application's boot class path, rather
* than dynamically loaded at runtime.)
*
* The late-timer preservation options are:
*
* - NONE - timer events for a late timer are not generated.
*
- ALL - timer events for a late timer are always generated.
*
- LAST - only one timer event is generated for a late timer, that event
* corresponding to the most recent firing of the timer.
*
*/
public final class TimerPreserveMissed implements Serializable {
/**
* An integer representation of {@link #NONE}.
*/
public static final int PRESERVE_NONE = 0;
/**
* An integer representation of {@link #ALL}.
*/
public static final int PRESERVE_ALL = 1;
/**
* An integer representation of {@link #LAST}.
*/
public static final int PRESERVE_LAST = 2;
/**
* A string representation of {@link #NONE}.
*/
public static final String NONE_STRING = "None";
/**
* A string representation of {@link #ALL}.
*/
public static final String ALL_STRING = "All";
/**
* A string representation of {@link #LAST}.
*/
public static final String LAST_STRING = "Last";
/**
* Preserve-missed value for the NONE option.
*/
public static final TimerPreserveMissed NONE = new TimerPreserveMissed(PRESERVE_NONE);
/**
* Preserve-missed value for the ALL option.
*/
public static final TimerPreserveMissed ALL = new TimerPreserveMissed(PRESERVE_ALL);
/**
* Preserve-missed value for the LAST option.
*/
public static final TimerPreserveMissed LAST = new TimerPreserveMissed(PRESERVE_LAST);
/**
* Get a TimerPreserveMissed object from an integer value.
* @param option the preserve-missed option as an integer.
* @return a TimerPreserveMissed object corresponding to option.
* @throws IllegalArgumentException if option is not a valid
* preserve-missed option value.
*/
public static TimerPreserveMissed fromInt(int option) throws IllegalArgumentException {
switch (option) {
case PRESERVE_NONE: return NONE;
case PRESERVE_ALL: return ALL;
case PRESERVE_LAST: return LAST;
default: throw new IllegalArgumentException("Invalid preserve-missed value: " + option);
}
}
/**
* Get a TimerPreserveMissed object from a string value.
* @param option the preserve-missed option as a string, for example as returned
by the {@link #toString()} method (case insensitive).
* @return a TimerPreserveMissed object corresponding to option.
* @throws NullPointerException if option is null.
* @throws IllegalArgumentException if option is not a valid
* preserve-missed option value.
* @since SLEE 1.1
*/
public static TimerPreserveMissed fromString(String option) throws NullPointerException, IllegalArgumentException {
if (option == null) throw new NullPointerException("option is null");
if (option.equalsIgnoreCase(NONE_STRING)) return NONE;
if (option.equalsIgnoreCase(ALL_STRING)) return ALL;
if (option.equalsIgnoreCase(LAST_STRING)) return LAST;
throw new IllegalArgumentException("Invalid preserve-missed value: " + option);
}
/**
* Get an integer value representation for this TimerPreserveMissed object.
* @return an integer value representation for this TimerPreserveMissed object.
*/
public int toInt() {
return option;
}
/**
* Determine if this TimerPreserveMissed object represents the NONE option.
*
* This method is effectively equivalent to the conditional test:
* (this == NONE), ie. the code:
*
* if (timerPreserveMissed.isNone()) ...
*
* is interchangeable with the code:
*
* if (timerPreserveMissed == TimerPreserveMissed.NONE) ...
*
* @return true if this object represents the NONE option,
* false otherwise.
*/
public boolean isNone() {
return option == PRESERVE_NONE;
}
/**
* Determine if this TimerPreserveMissed object represents the ALL option.
*
* This method is effectively equivalent to the conditional test:
* (this == ALL), ie. the code:
*
* if (timerPreserveMissed.isAll()) ...
*
* is interchangeable with the code:
*
* if (timerPreserveMissed == TimerPreserveMissed.ALL) ...
*
* @return true if this object represents the ALL option,
* false otherwise.
*/
public boolean isAll() {
return option == PRESERVE_ALL;
}
/**
* Determine if this TimerPreserveMissed object represents the LAST option.
*
* This method is effectively equivalent to the conditional test:
* (this == LAST), ie. the code:
*
* if (timerPreserveMissed.isLast()) ...
*
* is interchangeable with the code:
*
* if (timerPreserveMissed == TimerPreserveMissed.LAST) ...
*
* @return true if this object represents the LAST option,
* false otherwise.
*/
public boolean isLast() {
return option == PRESERVE_LAST;
}
/**
* Compare this preserve-missed option object for equality with another.
* @param obj the object to compare this with.
* @return true if obj is an instance of this class
* representing the same preserve-missed option as this, false
* otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) return true;
return (obj instanceof TimerPreserveMissed) && ((TimerPreserveMissed)obj).option == option;
}
/**
* Get a hash code value for this preserve-missed option object.
* @return a hash code value.
*/
public int hashCode() {
return option;
}
/**
* Get the textual representation of the TimerPreserveMissed object.
* @return the textual representation of the TimerPreserveMissed object.
*/
public String toString() {
switch (option) {
case PRESERVE_NONE: return NONE_STRING;
case PRESERVE_ALL: return ALL_STRING;
case PRESERVE_LAST: return LAST_STRING;
default: return "TimerPreserveMissed in Unknown and Invalid State";
}
}
/**
* Private constructor to prevent unauthorized object creation.
*/
private TimerPreserveMissed(int option) {
this.option = option;
}
/**
* Resolve deserialisation references so that the singleton property of each
* enumerated object is preserved.
*/
private Object readResolve() throws StreamCorruptedException {
try {
return fromInt(option);
}
catch (IllegalArgumentException iae) {
throw new StreamCorruptedException("Invalid internal state found");
}
}
/**
* The internal state representation of the enumerated type.
*/
private final int option;
}