drools中使用excel

• • 在drools中如果使用规则表

        典型的用法就是根据excel创建KnowledgeBase,然后将它丢给session执行，执行的参数和结果都在params里面

  package com.xxx.yyyy;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.InputStream;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import junit.framework.Assert;
  
  import org.drools.KnowledgeBase;
  import org.drools.KnowledgeBaseFactory;
  import org.drools.builder.DecisionTableConfiguration;
  import org.drools.builder.DecisionTableInputType;
  import org.drools.builder.KnowledgeBuilder;
  import org.drools.builder.KnowledgeBuilderFactory;
  import org.drools.builder.ResourceType;
  import org.drools.definition.KnowledgePackage;
  import org.drools.io.ResourceFactory;
  import org.drools.runtime.StatelessKnowledgeSession;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.Parameterized;
  import org.junit.runners.Parameterized.Parameters;
  
  @RunWith(Parameterized.class)  
  public class IsP4PTest{
  	 private IsP4P param;  
  	 private String extected;  
  	      
  	 public IsP4PTest(IsP4P param,String extected) {  
  	        this.param = param;  
  	        this.extected = extected;  
  	 }  
  	    
  	public static class IsP4P {
  		private String productLine;
  		private String productType;
  		private String playType;
  		
  		public IsP4P(String productLine,String productType,String playType){
  			this.productLine =  productLine;
  		    this.productType = productType;
  		    this.playType = playType;
  		}
  		
  		public Map getParams(){
  			Map params = new HashMap();
  			
  			params.put("productLine", productLine);
  			params.put("productType", productType);
  			params.put("playType", playType);
  			
  			return params;
  		}
  	} 
  	
  	public void testExcel(String fileName, Map params)
  			throws Exception {
  		System.out.println("---------------begin------------------------");
  		
  		DecisionTableConfiguration dtableconfiguration = KnowledgeBuilderFactory
  				.newDecisionTableConfiguration();
  		dtableconfiguration.setInputType(DecisionTableInputType.XLS);
  		final KnowledgeBuilder kbuilder = KnowledgeBuilderFactory
  				.newKnowledgeBuilder();
  		File file = new File("D:\\iwork-space\\rule\\src\\test\\resources\\"
  				+ fileName);
  		InputStream is = new FileInputStream(file);
  
  		// InputStream is = new ClassPathResource(fileName).getInputStream();
  		kbuilder.add(ResourceFactory.newInputStreamResource(is,"UTF-8"),
  				ResourceType.DTABLE);
  		if (kbuilder.hasErrors()) {
  			System.out.println(kbuilder.getErrors().toString());
  		}
  		Collection pkgs = kbuilder.getKnowledgePackages();
  		KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
  		kbase.addKnowledgePackages(pkgs);
  
  		StatelessKnowledgeSession ksession = kbase
  				.newStatelessKnowledgeSession();
  		ksession.execute(Arrays.asList(new Object[] {params}));
  		
  		System.out.println("---------------end------------------------");
  	}
        
      @Parameters  
      public static Collection contructData(){  
          return Arrays.asList(new Object[][]{  
                  {new IsP4P("aa","true","null"),"true"},  
                  {new IsP4P("bb","true","null"),"true"},  
                  {new IsP4P("cc","true","aa"),"false"},  
                  {new IsP4P("dd","false","bb"),"other"}  
          });  
      }  
      
      @Test
      public void testP4P() throws Exception{
      	Map params = new HashMap();
      	params.putAll(param.getParams());
      	testExcel("ka/isP4P.xls", params);
          Assert.assertEquals(extected, params.get("isP4P"));  
      }  
  }
  

   

• 什么时候考虑使用规则表

  如果规则可以表示成 templates+data(模板＋数据),可以考虑使用 decision tables。在决策表的每一行，采集数据和模板一起生成规则。使用基于决策表的Spreadsheet的API在Drools-decisiontables模块中。只有一个类：SpreadsheetCompiler. 这个类可以操作各种格式的Spreadsheet，并生成DRL规则（然后就可以常规的方式使用）。

 

• 一个典型的规则表的格式
  
   

 

1. RuleSet关键字是必须的，名字是可选的
2. Import语句非常像java的import，如果有多个import，用逗号隔开
3. RuleTable关键字也是必须的，它指示了后面将会有一批rule，ruletable的名称将会作为以后生成rule的前缀
4. 条件如果不写的话默认就是==, 比如上面的contract.get("productLine"),其实就是contract.get("productLine") == $param, 如果有多个参数可以使用$1,$2,比如我们经常用到的一个区间数据，这个占位符就派上用场了
5. 所有的关键字都是忽略大小写的
6. 默认情况下规则引擎只解析第一个sheet的规则

• 规则区域所支持的关键字

Keyword	Value	Usage
RuleSet	The package name for the generated DRL file. Optional, the default is rule_table.(默认值是rule_table)	Must be First entry.
Sequential	"true" or "false". If "true", then salience is used to ensure that rules fire from the top down.(规则触发是从上朝下，如果是false就是乱序)	Optional, at most once. If omitted, no firing order is imposed.
Import	A comma-separated list of Java classes to import.(逗号隔开)	Optional, may be used repeatedly.
Variables	Declarations of DRL globals, i.e., a type followed by a variable name. Multiple global definitions must be separated with a comma. 全局变量定义，多个用逗号隔开	Optional, may be used repeatedly.
Functions	One or more function definitions, according to DRL syntax.	Optional, may be used repeatedly.
Queries	One or more query definitions, according to DRL syntax.	Optional, may be used repeatedly.

        需要特别注意的是这些关键字只能出现一次!

 

• Rule Table的头部所支持的关键字

Keyword	Initial	Value	Usage
NAME	N	Provides the name for the rule generated from that row. The default is constructed from the text following the RuleTable tag and the row number.	At most one column
DESCRIPTION	I	A text, resulting in a comment within the generated rule.	At most one column
CONDITION	C	Code snippet and interpolated values for constructing a constraint within a pattern in a condition.	At least one per rule table
ACTION	A	Code snippet and interpolated values for constructing an action for the consequence of the rule.	At least one per rule table
METADATA	@	Code snippet and interpolated values for constructing a metadata entry for the rule.	Optional, any number of columns

• 将excel编译成规则文件

   

package com.xxx.yyy;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

import org.drools.decisiontable.InputType;
import org.drools.decisiontable.SpreadsheetCompiler;
import org.junit.Test;

public class SpreadsheetCompilerTest {
	@Test
	public void compile() throws FileNotFoundException{
		File file = new File("D:\\iwork-space\\rule\\src\\test\\resources\\ka\\isP4P.xls");
		InputStream is = new FileInputStream(file);
		
		SpreadsheetCompiler converter = new SpreadsheetCompiler();
		String drl = converter.compile(is, InputType.XLS); //--------exception here-------- 
		System.out.println("\n\n" + drl);
	}
}

        编译后的结果如下：

      

  这个地方注意一点，==和equals是相同的，!= 和 !equals是相同的

 

     // Similar to: java.util.Objects.equals(person.getFirstName(), "John")

     // so (because "John" is not null) similar to:

     // "John".equals(person.getFirstName())

     Person( firstName == "John" )

 

     The != operator has null-safe !equals() semantics:

     // Similar to: !java.util.Objects.equals(person.getFirstName(), "John")

      Person( firstName != "John" )