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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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package org.jgroups.protocols.rules;

import org.jgroups.logging.Log;

/**
 * A rule with a condition and (optional) action. When a rule is run, the condition is checked with {@link #eval()} and
 * - if true - the action is triggered with {@link #trigger()}.
 * @author Bela Ban
 * @since  3.3
 */
public abstract class Rule implements Runnable {
    protected SUPERVISOR sv;  // set when rule is installed
    protected Log        log;         // set when rule is installed

    public Rule supervisor(SUPERVISOR sv) {this.sv=sv;   return this;}
    public Rule log(Log log)              {this.log=log; return this;}

    /** Returns the name of the rule. Should be unique if a rule needs to be uninstalled */
    public abstract String name();

    /** Describes what the rules does */
    public abstract String description();

    /** Called when rule is installed */
    public void init() {}

    /** Called when rule is uninstalled */
    public void destroy() {}

    /** Evaluates the condition. If true, the rule is triggered. If true, the next execution of {@link #condition()}
     * should return a non-null string */
    public abstract boolean eval();

    /** Returns a description of the condition that led to {@link #eval()} returning true */
    public abstract String condition();

    /** The action of the rule. Triggered if {@link #eval()} returned true */
    public abstract void trigger() throws Throwable;

    public void run() {
        if(!eval())
            return;
        try {
            String condition=condition();
            if(condition == null)
                condition="executed rule " + name();
            sv.addCondition(condition);
            if(log.isTraceEnabled())
                log.trace(sv.getLocalAddress() + ": executing rule " + name());
            trigger();
        }
        catch(Throwable t) {
            log.error(sv.getLocalAddress() + ": failed executiong rule " + name(), t);
        }
    }
}