Struts + Jboss Drools 规则引擎

                                  Struts+Jboss Drools规则引擎：一个Stock小小例子

    第一篇写在JavaEye的东西，很粗糙！

 

   

1、从try输入信息，Struts Action控制其跳转，Drools规则引擎执行规则之后将信息提供给Struts Action。

1.1 BusinessLayer类

代码如下：

package com.stock;

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;

//加载Drools规则库
//评估该股票即可

public class BusinessLayer {
      //定义规则文件字符串
 public final static String file="Business.drl";
 public static RuleBase businessRule;
 public static RuleBase rr;
 
 private static RuleBase readRules() throws Exception {
  //读入规则文件
  Reader source = new InputStreamReader(BusinessLayer.class
    .getResourceAsStream(file));

  PackageBuilder builder = new PackageBuilder();

  builder.addPackageFromDrl(source);

  Package pkg = builder.getPackage();

  RuleBase ruleBase = RuleBaseFactory.newRuleBase();

  ruleBase.addPackage(pkg);

  return ruleBase;

 }
 
 public static void evaluateStockPurchase(UserOffer stockToBuy)
 {
     try {
   businessRule=readRules();
  } catch (Exception e) {
   // TODO 自动生成 catch 块
   e.printStackTrace();
  } 
  
  
  WorkingMemory workingMemory=businessRule.newStatefulSession();
  workingMemory.insert(stockToBuy);
  
  //我忘记激活规则了
  System.out.println("激活规则");
  System.out.println("-----------");
  
  workingMemory.fireAllRules();
 }
 
 public static void ee()
 {
  try {
   rr=readRules();
  } catch (Exception e) {
   // TODO 自动生成 catch 块
   e.printStackTrace();
  }
  
  WorkingMemory work=rr.newStatefulSession();
  work.insert(new UserOffer());
  work.fireAllRules();   //该处代码仅供JUnit测试使用！

 }
}

1.2 UserOffer类

 

package com.stock;

public class UserOffer {
 private final static String Yes = "Yes";

 private final static String No = "No";

 private String stockName;

 private String stockPrice;

 private String stockQuantity;

 private String commendPurchase;

 public String getCommendPurchase() {
  return commendPurchase;
 }

 public void setCommendPurchase(String commendPurchase) {
  this.commendPurchase = commendPurchase;
 }

 public String getStockName() {
  return stockName;
 }

 public void setStockName(String stockName) {
  this.stockName = stockName;
 }

 public String getStockPrice() {
  return stockPrice;
 }

 public void setStockPrice(String stockPrice) {
  this.stockPrice = stockPrice;
 }

 public String getStockQuantity() {
  return stockQuantity;
 }

 public void setStockQuantity(String stockQuantity) {
  this.stockQuantity = stockQuantity;
 }
}

3、Struts Action

/*
 * Generated by MyEclipse Struts
 * Template path: templates/java/JavaClass.vtl
 */
package com.stock.dao.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.stock.BusinessLayer;
import com.stock.UserOffer;
import com.stock.dao.form.TryForm;

/**
 * MyEclipse Struts
 * Creation date: 05-13-2009
 *
 * XDoclet definition:
 * @struts.action path="/try" name="tryForm" input="/form/try.jsp" scope="request" validate="true"
 */
public class TryAction extends Action {
 /*
  * Generated Methods
  */

 /**
  * Method execute
  * @param mapping
  * @param form
  * @param request
  * @param response
  * @return ActionForward
  */
 public ActionForward execute(ActionMapping mapping, ActionForm form,
   HttpServletRequest request, HttpServletResponse response) {
  TryForm tryForm = (TryForm) form;// TODO Auto-generated method stub

  UserOffer user = null;

  if (null == user) {
   user = new UserOffer();
  }

  //设置user的数值
  //从Form获得
  user.setStockName(request.getParameter("stockname"));

  //调用商业逻辑
  BusinessLayer.evaluateStockPurchase(user);
       
  
  //查看执行方法
  BusinessLayer.ee();
  
  if ("Yes".equals(user.getCommendPurchase())) {
   return mapping.findForward("yes");
  } else {
   return mapping.findForward("no");
  }

 }
}

 

1.4 JBoss Drools 规则文件

#created on: 2009-5-13
package com.stock;

#list any import classes here.
import com.stock.UserOffer;

#declare any global variables here

 

rule "Your First Rule"
 
 when
  #conditions
  $s:UserOffer( stockName=="ABC")
 then
  #actions
  #返回名字为ABC公司的名称 ，利用Action来控制
  $s.setCommendPurchase("Yes");
  System.out.println("规则引擎执行！");
  
end

rule "new rule"
 when
  
 then
  System.out.println("Hello Drools，测试规则引擎用例！");
end

 

测试结果：

 

 

 

 

 

输入：ABC