JBoss Drools 规则引擎示例程序

参考资料：http://leowzy.javaeye.com/blog/603941

 

如下图所示建立工程：

 

代码如下：

DroolsTest.java

package com.sample;import java.io.InputStreamReader;import java.io.Reader;import org.drools.RuleBase;import org.drools.RuleBaseFactory;import org.drools.WorkingMemory;import org.drools.compiler.PackageBuilder;import org.drools.rule.Package;public class DroolsTest {public static final void main(String[] args) {try {RuleBase ruleBase = readRule();WorkingMemory workingMemory = ruleBase.newStatefulSession();Message message = new Message();message.setMessage("Hello World");message.setStatus(Message.HELLO);workingMemory.insert(message);workingMemory.fireAllRules();} catch (Throwable t) {t.printStackTrace();}}private static RuleBase readRule() throws Exception {Reader source = new InputStreamReader(DroolsTest.class.getResourceAsStream("./Sample.drl"));PackageBuilder builder = new PackageBuilder();builder.addPackageFromDrl(source);Package pkg = builder.getPackage();RuleBase ruleBase = RuleBaseFactory.newRuleBase();ruleBase.addPackage(pkg);return ruleBase;}public static class Message {public static final int HELLO = 0;public static final int GOODBYE = 1;public static final int GAME_OVER = 2;private String message;private int status;public String getMessage() {return this.message;}public void setMessage(String message) {this.message = message;}public int getStatus() {return this.status;}public void setStatus(int status) {this.status = status;}}}

Sample.drl

package com.sampleimport com.sample.DroolsTest.Message;rule "Hello World"when m : Message( status == Message.HELLO, message : message )then System.out.println( message ); m.setMessage( "Goodbye cruel world" ); m.setStatus( Message.GOODBYE ); update( m );endrule "GoodBye"no-loop truewhen m : Message( status == Message.GOODBYE, message : message )then System.out.println( message ); m.setStatus(Message.GAME_OVER); m.setMessage("game over now!"); update( m );endrule "game over"when m : Message( status == Message.GAME_OVER)then System.out.println( m.getMessage() ); end  

 

其他资料：

http://fu8000888.dns28.trtr.cn/article.asp?id=11

http://www.javaeye.com/topic/659752