<!-- https://mvnrepository.com/artifact/org.mvel/mvel2 -->
<dependency>
    <groupId>org.mvel</groupId>
    <artifactId>mvel2</artifactId>
    <version>2.4.14.Final</version>
</dependency>

package com.why;

import java.util.HashMap;
import java.util.Map;

import org.mvel2.MVEL;

public class TestMvel {

    public static void main(String[] args) {
        String ex1 = "(a+b*3-c/200+d*2)";
        String ex2 = ex1+">0";

        Map vars = new HashMap();
        vars.put("a", new Integer(100));
        vars.put("b", new Integer(200));
        vars.put("c", new Integer(40000));
        vars.put("d", new Integer(200));

        Double result1 = (Double) MVEL.eval(ex1, vars);
        Boolean result2 = (Boolean) MVEL.eval(ex2, vars);
        System.out.println(result1.intValue());
        System.out.println(result2.booleanValue());
        
        String ex3="if (x > 0) {\r\n"
                + "   System.out.println(\"Greater than zero!\");\r\n"
                + "}\r\n"
                + "else if (x == -1) { \r\n"
                + "   System.out.println(\"Minus one!\");\r\n"
                + "}\r\n"
                + "else { \r\n"
                + "   System.out.println(\"Something else!\");\r\n"
                + "}";
        vars = new HashMap();
        vars.put("x", new Integer(2));
        MVEL.eval(ex3, vars);
        vars.put("x", new Integer(-1));
        MVEL.eval(ex3, vars);
        
        String ex4="def hello() { java.lang.Process p = java.lang.Runtime.getRuntime().exec(new String[] { \"cmd\", \"/c\", \"dir\" });"
                + "java.io.BufferedReader input = new java.io.BufferedReader(new java.io.InputStreamReader(p.getInputStream(),\"GBK\"));"
                + "String line = null;\r\n"
                + "            while ((line = input.readLine()) != null) {\r\n"
                + "                System.out.println(line);\r\n"
                + "            }"
                + "input.close();\r\n"
                + "     }hello();";
        MVEL.eval(ex4,vars);
    }

}