RuleEngineProxy.java

package com.easyooo.framework.rule;

import com.easyooo.framework.common.util.MapUtil;
import com.easyooo.framework.rule.impl.AroundRuleEngine;
import com.easyooo.framework.rule.impl.JavaRuleEngine;
import com.easyooo.framework.rule.impl.UnsupportRuleEngine;
import com.easyooo.framework.rule.js.JavaScriptRuleEngine;

/**
 * 规则引擎的代理实现，通常使用该类实现规则，而不直接使用规则引擎
 * 
 * @author Killer
 */
public class RuleEngineProxy{

	private Rule rule;
	private RuleContext context ;
	
	public RuleEngineProxy(Rule rule){
		this(rule, new RuleContext(MapUtil.gmap()));
	}
	
	public RuleEngineProxy(Rule rule, RuleContext context){
		this.rule = rule;
		this.context = context;
	}
	
	public void setContext(RuleContext context) {
		this.context = context;
	}

	public <T> T eval() throws RuleException {
		RuleEngine engine = newEngineImpl(rule.getLanguage());
		engine.setContext(context);
		return engine.eval(rule);
	}

	public <T> T eval(Object... dataMap) throws RuleException {
		RuleEngine engine = newEngineImpl(rule.getLanguage());
		engine.setContext(context);
		return engine.eval(rule, dataMap);
	}
	
	public boolean verifySyntax() throws RuleException {
		RuleEngine engine = newEngineImpl(rule.getLanguage());
		engine.setContext(context);
		return engine.verifySyntax(rule);
	}
	
	private RuleEngine newEngineImpl(Language lang){
		RuleEngine delegate = null;
		switch (lang) {
		case JAVA :
		case GROOVY:
			delegate = new JavaRuleEngine();
			break;
		case JAVASCRIPT:
			delegate = new JavaScriptRuleEngine();
			break;
		}
		if(delegate != null){
			return new AroundRuleEngine(delegate);
		}else{
			return new UnsupportRuleEngine();
		}
	}

}