Java调用js做的规则引擎

package com.chinamobile.scm.project.util;
import com.chinamobile.scm.project.dto.ButtonRuleDto;
import com.chinamobile.scm.project.manual.mapper.PurchaseWorkbenchQueryReturnDto;
import com.google.common.collect.Maps;
import org.springframework.cglib.beans.BeanMap;

import javax.script.Bindings;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import java.util.*;

/**
 * 脚本规则引擎 杨航 [email protected]
 */
public class RuleUtil {
    /**
     * 按钮规则列表
     */
    public static List buttonDisplayRules=new ArrayList<>();

    public static final String argfront="var jsresult=";
    private static ScriptEngine javaScriptEngine;

    static {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine scriptEngine = manager.getEngineByName("js");
        if (scriptEngine == null) {
            throw new RuntimeException("获取脚本解析引擎失败");
        }
        javaScriptEngine = scriptEngine;
    }

    public static Object execute(String script) throws ScriptException {
        return javaScriptEngine.eval(script);
    }
    public static Object executeForAttribute(String script, String attributeName) throws ScriptException {
        javaScriptEngine.eval(script);
        return javaScriptEngine.getContext().getAttribute(attributeName);
    }

    public static Object executeForFirstAttribute(String script) throws ScriptException {

        //这里重新获取一个JavaScript解析引擎是为了避免代码中有其他调用工具类的地方的变量干扰
        //重新获取后,这个JavaScript解析引擎只执行了这次传入的代码,不会保存其他地方的变量
        //全局的解析器中会保存最大200个变量,JavaScript解析引擎本身最大保存100个变量
//        ScriptEngineManager manager = new ScriptEngineManager();
//        ScriptEngine scriptEngine = manager.getEngineByName("js");
//        if (scriptEngine == null) {
//            throw new RuntimeException("获取脚本解析引擎失败");
//        }

        javaScriptEngine.eval(script);
        ScriptContext context = javaScriptEngine.getContext();
        if (context == null) {
            return null;
        }
        Bindings bindings = context.getBindings(ScriptContext.ENGINE_SCOPE);
        if (bindings == null) {
            return null;
        }
        Set> entrySet = bindings.entrySet();
        if (entrySet == null || entrySet.isEmpty()) {
            return null;
        }
        for (Map.Entry entry : entrySet) {
            if (entry.getValue() != null) {
                return entry.getValue();
            }
        }
        return null;
    }

    public static boolean isDisplay(String rule, Object bean)  throws ScriptException
    {

        Map args= beanToMap( bean);
        if(args!=null&&args.size()>0) {
            for (Map.Entry entry : args.entrySet()) {
                String mapKey = entry.getKey();
                Object param = entry.getValue();
                String s = "";
                if (param instanceof Integer) {
                    int value = ((Integer) param).intValue();
                    s = String.valueOf(value);
                    rule = rule.replace(mapKey, s);
                } else if (param instanceof String) {
                    s = (String) param;
                    rule = rule.replace(mapKey, "'" + s + "'");
                } else if (param instanceof Double) {
                    double d = ((Double) param).doubleValue();
                    s = String.valueOf(d);
                    rule = rule.replace(mapKey, s);
                } else if (param instanceof Float) {
                    float f = ((Float) param).floatValue();
                    s = String.valueOf(f);
                    rule = rule.replace(mapKey, s);
                } else if (param instanceof Long) {
                    long l = ((Long) param).longValue();
                    s = String.valueOf(l);
                    rule = rule.replace(mapKey, s);
                } else if (param instanceof Boolean) {
                    boolean b = ((Boolean) param).booleanValue();
                    s = String.valueOf(b);
                    rule = rule.replace(mapKey, s);
                } else if (param instanceof Date) {
                    Date d = (Date) param;
                    s = String.valueOf(d);
                    rule = rule.replace(mapKey, s);
                }
               // System.out.println(mapKey + ":" + rule);
            }
        }
        boolean testExecuteForFirstAttribute = (boolean)executeForFirstAttribute(argfront+rule);
        return testExecuteForFirstAttribute;
    }
    /**
     * 将对象装换为map
     *
     * @param bean
     * @return
     */
    private static  Map beanToMap(T bean) {
        Map map = Maps.newHashMap();
        if (bean != null) {
            BeanMap beanMap = BeanMap.create(bean);
            for (Object key : beanMap.keySet()) {
                map.put(key + "", beanMap.get(key));
            }
        }
        return map;
    }

    /**
     * 示例
     * @throws ScriptException
     */
    public static void ruleSample1() throws ScriptException {
        Integer testExecute = (Integer) execute("2*3");
        Object myb=execute("var a = 6==2*3");
        String testExecuteForAttribute = (String) myb;
       // String testExecuteForAttribute = (String) executeForAttribute("var value = 'a'+ 'dc'", "value");
        Boolean testExecuteForFirstAttribute = (Boolean)executeForFirstAttribute("var a = 6==2*3");

        System.out.println(testExecute);
        System.out.println(testExecuteForAttribute);
        System.out.println(testExecuteForFirstAttribute);




        long start = System.currentTimeMillis();
        for(int i=0;i<51;i++) {
            ButtonRuleDto  onbu=new ButtonRuleDto();
            onbu.setRuleId(i+"");
          onbu.setButtonRuleScript(  "nextStage=='1'&&(currentStage=='2'||nextStage=='1')" );
          onbu.setButtonId(i+"");
            onbu.setButtonName("测试按钮");
            buttonDisplayRules.add(onbu);
           // System.out.println(testExecuteForFirstAttribute2);
        }



        PurchaseWorkbenchQueryReturnDto purchaseWorkbenchQueryReturnDto=new PurchaseWorkbenchQueryReturnDto();
        purchaseWorkbenchQueryReturnDto.setNextStage("1");
        purchaseWorkbenchQueryReturnDto.setCurrentStage("2");
        long useTime = System.currentTimeMillis() - start;
        StringBuilder prefix = new StringBuilder();
        List  testlist= verfiyButtonRule(purchaseWorkbenchQueryReturnDto);
        prefix.append("Used Time (ms):");
        prefix.append(useTime);
        System.out.println("示例结束  ...."+prefix.toString());
    }

    /**
     * 验证可显示的按钮列表
     * @param purchaseWorkbenchQueryReturnDto
     * @return
     * @throws ScriptException
     */
    public static List verfiyButtonRule(PurchaseWorkbenchQueryReturnDto purchaseWorkbenchQueryReturnDto)throws ScriptException
    {
        List strings=new ArrayList<>();
        for( ButtonRuleDto buttonRuleDto: buttonDisplayRules) {

            Boolean verfiyflg = isDisplay(buttonRuleDto.getButtonRuleScript(), purchaseWorkbenchQueryReturnDto);
           if(verfiyflg)
           {
               strings.add(buttonRuleDto.getButtonId());
           }
        }
        return strings;
    }
}