Rule

java.lang.Object
- org.jgroups.protocols.rules.Rule

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

CheckFDMonitor, SampleRule
```
public abstract class Rule
extends java.lang.Object
implements java.lang.Runnable
```
A rule with a condition and (optional) action. When a rule is run, the condition is checked with eval() and - if true - the action is triggered with trigger().

Since:

3.3

Author:

Bela Ban

Field Summary

Fields
Modifier and Type Field Description

protected Log log

protected SUPERVISOR sv

Constructor Summary

Constructors
Constructor Description

Rule()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract java.lang.String`	`condition()`	Returns a description of the condition that led to `eval()` returning true
`abstract java.lang.String`	`description()`	Describes what the rules does
`void`	`destroy()`	Called when rule is uninstalled
`abstract boolean`	`eval()`	Evaluates the condition.
`void`	`init()`	Called when rule is installed
`Rule`	`log(Log log)`
`abstract java.lang.String`	`name()`	Returns the name of the rule.
`void`	`run()`
`Rule`	`supervisor(SUPERVISOR sv)`
`abstract void`	`trigger()`	The action of the rule.

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

- Field Detail
  - sv
```
protected SUPERVISOR sv
```
  - log
```
protected Log log
```
- Constructor Detail
  - Rule
```
public Rule()
```
- Method Detail
  - supervisor
```
public Rule supervisor(SUPERVISOR sv)
```
  - log
```
public Rule log(Log log)
```
  - name
```
public abstract java.lang.String name()
```
    Returns the name of the rule. Should be unique if a rule needs to be uninstalled
  - description
```
public abstract java.lang.String description()
```
    Describes what the rules does
  - init
```
public void init()
```
    Called when rule is installed
  - destroy
```
public void destroy()
```
    Called when rule is uninstalled
  - eval
```
public abstract boolean eval()
```
    Evaluates the condition. If true, the rule is triggered. If true, the next execution of condition() should return a non-null string
  - condition
```
public abstract java.lang.String condition()
```
    Returns a description of the condition that led to eval() returning true
  - trigger
```
public abstract void trigger()
                      throws java.lang.Throwable
```
    The action of the rule. Triggered if eval() returned true
    
    Throws:
    
    java.lang.Throwable
  - run
```
public void run()
```
    Specified by:
    
    run in interface java.lang.Runnable